Here’s the part most size comparisons skip. Doubling the floor area from 20m² to 40m² doesn’t halve your cost per square metre. It barely moves it, from £3,015 to £2,933. That’s a 3% saving for twice the room.

This page shows the arithmetic behind all three columns, names the source behind every rate, and explains where the real step changes actually sit. For the wider picture, see our guide to house extension costs in South London.

The Short Answer

• Single-storey build in London runs £2,300 to £3,400 per m² (HomeOwners Alliance, 2026), with a £2,850 midpoint. The UK range is £1,800 to £3,000 per m².
• At that midpoint plus £3,300 of fees, you get about £60,000 at 20m², about £88,000 at 30m² and about £117,000 at 40m², all excluding a new kitchen.
• Indicative all-in bands, no kitchen: £52,000 to £71,000 at 20m², £75,000 to £105,000 at 30m², £98,000 to £139,000 at 40m².
• Cost per m² falls from £3,015 to £2,943 to £2,933. Scale buys you almost nothing, because fees, the opening steel, the drain connection and the kitchen don’t scale with floor area.
• A new kitchen is a separate £20,000 line (Architecture for London, 2026), whatever size room you put it in.
• Going deeper can cost more than it saves, once you pass the 3m Permitted Development limit or need a second roof plane.

All figures are indicative for South London as at September 2026, not a quote. Your property, ground conditions and specification will move them.

The three sizes come to about £60,000, £88,000 and £117,000 before a kitchen

Every column below uses the same London build rate and the same fee stack. Nothing changes between them except the floor area, which is the only fair way to compare sizes.

Indicative for South London, September 2026. Build rate from HomeOwners Alliance (2026). Kitchen from Architecture for London (2026). Not a quote.

The 30m² column is the same worked example used in our main costs guide, so the two pages agree to the pound. It’s the anchor the other two sizes are built around.

Each column is arithmetic you can check yourself

The method is identical in all three cases. Multiply the floor area by the London rate, add the fee stack, then trim the extremes of the range inward.

20m² comes to about £60,000, with a band of £52,000 to £71,000

Twenty square metres at £2,300 per m² is £46,000. At £3,400 per m² it’s £68,000. Add £3,000 to £6,000 of fees and the raw span is £49,000 to £74,000.

That span overstates both ends. The lowest build rate rarely lands on the same job as the lowest fee bill, and the same is true in reverse. Trim £3,000 off each end and you get £52,000 to £71,000.

At the £2,850 midpoint, the build is £57,000. Add the £3,300 fee stack and you’re at £60,300, so call it about £60,000.

For what a fixed budget buys once fees are paid, see whether £50,000 is enough for an extension.

30m² comes to about £88,000, with a band of £75,000 to £105,000

Thirty square metres at £2,300 per m² is £69,000, and at £3,400 per m² it’s £102,000. Fees take the raw span to £72,000 to £108,000, trimmed to £75,000 to £105,000.

At the midpoint, the build is 30 × £2,850, which is £85,500, or about £85,000. Add £3,300 in fees and the total is £88,300. Put a £20,000 kitchen inside it and you’re at £108,300, or about £108,000.

40m² comes to about £117,000, with a band of £98,000 to £139,000

Forty square metres at £2,300 per m² is £92,000. At £3,400 per m² it’s £136,000. Fees take that to £95,000 to £142,000, trimmed to £98,000 to £139,000.

At the midpoint, the build is £114,000. Add £3,300 and the total is £117,300, or about £117,000. With a new kitchen, about £137,000.

For context, the HomeOwners Alliance 2026 UK size bands put 20m² at £40,000 to £56,000 and 50m² at £100,000 to £140,000. Those are UK figures. London carries a premium of roughly 19% on the midpoint, so treat the UK bands as a floor rather than a forecast.

Cost per square metre barely falls as the extension gets bigger

This is the finding that changes how you should think about size. Going from 20m² to 40m² cuts the all-in cost per square metre by £82, from £3,015 to £2,933. That’s about 3%.

Most people expect something closer to a bulk discount. It doesn’t arrive, because the build rate itself is flat. A bricklayer charges the same per metre of wall on a 40m² job as on a 20m² one.

The only thing genuinely diluted by scale is the fee stack. Spread £3,300 over 20m² and it’s £165 per m². Over 40m² it’s £83. That £82 saving per square metre is the entire economy of scale, and you can see where it goes.

Indicative all-in cost per square metre, South London, September 2026. Build rate is the £2,850 per m² midpoint of the HomeOwners Alliance 2026 London range of £2,300 to £3,400 per m². The £3,300 fee stack is held constant across all three sizes. Excludes a new kitchen. Indicative, not a quote.

Add a kitchen and the picture shifts more, because £20,000 spread over 40m² is £500 per m² against £1,000 per m² at 20m². The kitchen is the one big line that genuinely rewards a larger room.

Four costs ignore your floor area completely

These are the reason the per-square-metre curve flattens so fast. Each one is a fixed lump that lands whether you build 20m² or 40m².

Statutory and professional fees. The householder planning application fee is £548 in England, identical at any size (Planning Portal, 2026). A party wall award runs around £1,000 per neighbour, set by the shared wall, not your depth. A structural engineer’s calculations for a single rear opening cost roughly £725. Only building control moves, and it’s charged in floor-area bands, so it steps up rather than rising smoothly.

The steel over the opening. The beam that holds up the back of your house spans the opening you form in the existing rear wall. That width is fixed by the house. A 5m wide terrace needs the same beam whether the new room behind it is 20m² or 40m² deep.

The drainage connection. You connect to the existing soil stack and manhole once. If you build over or near a public sewer, the Thames Water agreement is a flat application, not a charge per square metre. Confirm your position with Thames Water before you design over a drain run.

The kitchen. A new kitchen is about £20,000 on the Architecture for London 2026 range of £15,000 to £40,000. That figure tracks the units, worktop and appliances you choose, not the floor area around them.

Each of those fees, and what triggers it, is broken down in the costs that sit outside the build rate.

Going bigger can add costs that a smaller extension avoids entirely

Scale cuts both ways. Past a certain depth or width, a larger extension picks up new cost lines rather than spreading old ones thinner.

A single-storey rear extension on a terrace or semi is limited to 3m deep under Permitted Development, and 4m on a detached house (Planning Portal, 2026). You can go to 6m and 8m through the Larger Home Extension prior approval route. That route carries its own fee, a neighbour consultation period and a real chance of refusal. This is general guidance, so confirm your own position with your borough.

Width has its own trigger. On a typical South London terrace, 40m² usually can’t be reached by going deeper alone, so you wrap around into the side return. That adds a second roof plane, more external wall per square metre of floor, and often a new opening in the flank wall.

Then there’s the middle of the plan. A deep 40m² extension puts the original rear wall a long way from daylight, so the zone behind it goes dark without rooflights or a glazed link. Heating a single large open volume also costs more every winter than heating two smaller rooms you can close off.

The right size is the one that fixes light and flow

A well-planned 20m² beats a poorly planned 40m², and the cost gap between them is roughly £57,000. That’s the most useful sentence on this page.

Size solves a floor area problem. It doesn’t solve a layout problem. If your kitchen is dark because it faces a side return with a 2m wall beside it, another 20m² of depth makes the dark bit deeper.

Homeowner forums keep returning to the same regret, most visibly on Mumsnet threads about extension regrets. All the new area went to the kitchen, and the living space stayed cramped. Nobody regrets the square metres. They regret how the square metres were divided.

Across South London rear and side return projects, the layout question that predicts satisfaction is not how deep the extension goes. It is where the daylight enters the old part of the house once the new roof is on. Clients who spent design time on that before agreeing a depth rarely ask for more area afterwards.

So run the test before you pick a number. Sketch the room at 20m², 30m² and 40m², then ask what each one does for the darkest corner of your current ground floor. If the answer is the same at all three, build the 20m² and spend the difference on glazing and a better kitchen.

What to do next

Pick your size from the layout, then price it, not the other way round. Take the area you actually need, multiply it by £2,300 to £3,400 per m², then add £3,000 to £6,000 of fees. Decide in writing whether the kitchen sits inside that number or outside it.

Then test the assumption that bigger is better value. On these 2026 figures it’s worth about £82 per square metre, which buys less daylight than a well-placed rooflight does.

If you’d like these three columns tested against your actual house and garden, Rapid Bee covers Bromley, Bexley, Greenwich, Lewisham and Southwark. We’ll talk through a realistic range before any drawings exist.

Frequently asked questions

* All figures on this page are indicative for South London as at September 2026 and are not a quote. Costs move with ground conditions, specification, site access and season. Regulatory guidance here is general; your property may differ, so confirm your position with your local authority, Thames Water or a party wall surveyor before committing.

The total is the easy part to learn. The useful questions are narrower. What sets each fee off? Who invoices you? When does it land in the programme? What pushes it to the top of its range, and what actually happens if you skip it? This page answers those questions one fee at a time.

These are the hidden costs of a house extension in the only sense that matters. They’re real, predictable and absent from most builders’ quotes. For how they sit inside the wider budget, start with our guide to house extension costs in South London.

The Short Answer

• Structural engineer, £550 to £900 for a straightforward extension, £1,200 to £1,500 for a wraparound (StructuralEngineerCalcs, 2026). Triggered by the first opening in a load-bearing wall.
• Party wall award, around £1,000 with a single agreed surveyor, typical range £900 to £2,700. If your neighbour appoints their own, £1,800 to £5,400 across two surveyors at £90 to £450 an hour (HomeOwners Alliance, 2026). You pay in nearly all cases.
• Building control, £600 to £1,320 plus VAT, banded by floor area. Bromley 2026 charges start at £600 ex VAT up to 10m² (bromley.gov.uk, 2026).
• Planning, £548 for a householder application in England from 1 April 2026. A Certificate of Lawfulness is half the householder rate, so £274.
• Drains are the wild card. A diversion runs £1,500 to £5,000 and a manhole relocation £2,000 to £4,500 (StructuralEngineerCalcs, 2026).
• All five fall due before the build money draws down, mostly at design stage, when there’s nothing on site to show for them.

All figures are indicative for South London as at September 2026, not a quote. Your property, borough and design will move them.

1. The structural engineer’s £550 is triggered by the first beam, not by the extension

Any new opening in a load-bearing wall needs calculations, and calculations need an engineer. A straightforward single-storey rear extension runs £550 to £900 (StructuralEngineerCalcs, 2026). A wraparound is £1,200 to £1,500, because it carries more beams, more load paths and more foundation design.

Who charges it. A consulting structural engineer, appointed by you, your architect or your builder. The invoice reaches you either way, so ask early who is instructing whom.

When it lands. Design stage, before building control sees a single drawing. Beam sizes, padstone details and foundation depths all live in that report. Your builder can’t order steel without it.

What pushes it to the top. Several openings rather than one. An L-shape or wraparound. A loft or basement in the same contract. Clay soil, tree roots or a neighbour’s basement, which all drive extra foundation design. Changing the layout after the calculations are issued means a revisit, and revisits are chargeable.

If you skip it. You don’t get the option. Building control won’t pass structural work without calculations, and no reputable steel fabricator will size a beam off a sketch.

2. The party wall award costs around £1,000 if your neighbour agrees, and up to £5,400 if they don’t

The Party Wall etc. Act 1996 is triggered by the work, not by your neighbour’s mood. Four common triggers cover most South London extensions:

• Cutting into or building off the shared wall between two houses
• Building right up to the boundary line
• Excavating within 3 metres of a neighbour’s structure and deeper than their foundations
• Excavating within 6 metres and below a 45 degree line from their foundations

Most terraces and semis trip at least one. A rear extension with strip foundations near a shared boundary usually trips the third.

What it costs. A single agreed surveyor acting for both owners is around £1,000, inside a typical range of £900 to £2,700. If your neighbour appoints their own surveyor instead, budget £1,800 to £5,400 across the two, at hourly rates of £90 to £450 (HomeOwners Alliance, 2026). The building owner pays in nearly all cases. That’s you.

When it lands. Before you start. Notice for works to the party wall itself runs two months, and notice for excavation or building on the line of junction runs one month. Design late and the award, not the builder, sets your start date.

What pushes it to the top. More adjoining owners. A mid-terrace has neighbours on both sides. A converted house next door can mean a freeholder and two leaseholders, each entitled to their own notice. Dissent, a disputed schedule of condition or a design change needing an addendum award all add surveyor hours.

If you skip it. Your neighbour can seek an injunction and stop the job mid-dig. You also lose the schedule of condition, the photographic record of their property before work starts. Without it, any crack that appears becomes your word against theirs.

This is general guidance and your boundary may differ. A party wall surveyor is the only person who can determine your position.

3. Building control is priced by floor area, and Permitted Development doesn’t exempt you

Every extension is subject to the Building Regulations, whatever the planning route. Falling under Permitted Development removes the planning fee, not this one. Budget £600 to £1,320 plus VAT.

The charge is banded by floor area and published by each borough, so you can look up your own figure before you finalise a design.

Paired plan check and inspection charges, excluding VAT. Bromley figures from bromley.gov.uk (2026), Bexley from bexley.gov.uk (2026). Indicative and subject to change, so confirm the current schedule with your own borough.

Who charges it. Your borough’s building control team, or a registered building control approver if you use the private route. The fee is broadly comparable; the difference is service and availability.

When it lands. In two parts. The plan check is paid on submission at design stage. The inspection charge covers site visits across the build, ending with the completion certificate.

What pushes it to the top. Crossing a band. A 41m² extension costs more to certify than a 39m² one in both boroughs above, which is worth knowing while the plan is still on paper. Repeat visits for work that isn’t ready also add cost.

If you skip it. No completion certificate. That document is the first thing a buyer’s solicitor asks for when you sell, and its absence stalls sales or forces an indemnity policy. Unauthorised work can also be opened up for inspection later, at your cost.

To see how building control and the other four fees sit inside a full budget, see what an extension costs by size.

4. Planning is £548, and the Certificate of Lawfulness you probably want is half that

Most single-storey rear extensions in South London fall under Permitted Development, so the £548 never applies. A householder planning application in England is £548 from 1 April 2026. A Certificate of Lawfulness is half the householder rate, which is £274.

What triggers the full application. Exceeding the depth, height or boundary limits of Permitted Development. An Article 4 direction, which is a borough order withdrawing those rights in a named area. Conservation area status. Living in a flat or maisonette, which has no Permitted Development rights at all. Previous extensions that have already used the allowance.

Who charges it. Your borough, paid through the Planning Portal. The drawings you submit are a separate cost from a designer or architect.

When it lands. At submission, months before a start on site. A householder application carries an eight week determination target, and a refusal plus resubmission can double that wait.

What pushes the total up. The application fee is fixed, but the process around it isn’t. Pre-application advice is charged separately by most boroughs. Redesign and resubmission means paying the designer twice even where a repeat application is exempt from a second fee.

If you skip it. If you genuinely have Permitted Development rights, you’ve skipped nothing. What you’ve skipped is the proof. A Certificate of Lawfulness is the document that shows a future buyer your extension was lawful, which is why £274 is usually money well spent.

5. Drains are the one line that can outgrow the other four combined

A drain or a manhole under your proposed footprint changes the job, not just the price. Diverting a drain costs £1,500 to £5,000, and relocating a manhole £2,000 to £4,500 (StructuralEngineerCalcs, 2026). Treat both as orders of magnitude. StructuralEngineerCalcs is a single trade source, and these figures have not yet been corroborated against a second publisher.

What triggers it. A public sewer, lateral drain or shared chamber crossing the ground you want to build on. Building over or near a public sewer usually needs a build over agreement with the sewerage undertaker, Thames Water across most of South London. That agreement carries its own charge, which varies, so ask them directly.

When it lands. The survey belongs at design stage. The diversion cost lands in groundworks, normally in the first three weeks on site, which is the worst possible moment to be renegotiating a price.

What pushes it to the top. Depth. A shared drain serving neighbouring houses. A chamber that has to stay accessible after the extension is built. Concrete surround or a new inspection chamber inside the finished room all add labour and disruption.

If you skip it. You don’t avoid the cost, you discover it. A CCTV drainage survey at design stage costs a small fraction of a diversion. Victorian and Edwardian terraces in South London routinely have a run or a chamber exactly where the new kitchen wants to go.

Every one of these fees is paid before the build money draws down

The cash flow problem is sharper than the total. All five fees cluster in design and pre-start, when there’s nothing on site to show for the spend. Stage payments to a builder start later, so the fees come out of savings first.

Indicative sequence of statutory and professional fees on a South London single-storey extension, September 2026. Planning fee from the Planning Portal schedule applying from 1 April 2026. Building control range from published borough schedules. Party wall figure from HomeOwners Alliance (2026) and engineer fee from StructuralEngineerCalcs (2026). Indicative, not a quote.

Plan the money in that order and nothing surprises you. Plan it as a single build cost and you’ll be paying professionals from the same pot you meant to spend on the kitchen.

Skipping a fee moves the cost, it doesn’t remove it

Each of these five has a consequence attached, and the consequence is always more expensive than the fee. That’s the honest case for paying them.

What to do next

Price the fees before you price the build. Look up your borough’s building control schedule by floor area, then book a CCTV drainage survey. Ask a party wall surveyor whether your foundations will sit within 3 metres of next door’s. Those three answers close most of the range between £3,000 and £6,000.

Then design with the numbers in front of you. Knowing that 41m² crosses a building control band, or that one extra opening adds an engineer’s revisit, only helps while the plan is still changeable.

Want these fees checked against your actual house and boundary? Rapid Bee works across Bromley, Bexley, Greenwich, Lewisham and Southwark, and will set out a realistic range before any drawings exist.

If you’re working to a fixed sum, see whether £50,000 is enough for an extension once these fees come off the top.

Frequently asked questions

* All figures on this page are indicative for South London as at September 2026 and are not a quote. Statutory charges change, boroughs publish their own schedules, and your property may sit outside every assumption here. Regulatory guidance is general, so confirm your position with your local authority or a party wall surveyor before committing.

That gap between the two answers is where most first budgets go wrong. £50,000 is a real, workable extension budget in South London. It just buys the box, and only rarely the box and everything you plan to put in it. This page shows the arithmetic, names the source behind every rate, and sets out what genuinely costs less.

For the full picture behind these numbers, see our guide to house extension costs in South London.

The Short Answer

• At the London single-storey rate of £2,300 to £3,400 per m² (HomeOwners Alliance, 2026), £50,000 of pure build buys 15 to 22m².
• Fees come off the top before that. Roughly £4,000 covers a £548 planning application and £600 to £1,320 plus VAT for building control. Add around £1,000 for a party wall award and £550 to £900 for a structural engineer.
• After fees, £50,000 buys 14 to 20m² finished. At the £2,850 per m² midpoint, the remaining £46,000 is about 16m².
• A new kitchen is a separate line of about £20,000 (Architecture for London, 2026). Budget it, or accept the old kitchen in the new room.
• Costing less: a garage conversion at £8,500 to £20,000 (HomeOwners Alliance, 2026). Or a shell-only build at £1,300 to £1,900 per m² excluding VAT (StructuralEngineerCalcs, 2026), fitted out later.

All figures are indicative for South London as at September 2026, not a quote. Your property, ground conditions and specification will move them.

£50,000 buys 14 to 20m² of finished extension once the fees are paid

Start with the build rate. The HomeOwners Alliance puts a single-storey extension in London at £2,300 to £3,400 per m² in 2026, against £1,800 to £3,000 per m² for the UK as a whole. Divide £50,000 by those London figures and you get 15 to 22m² of pure build.

Now take the fees out first, because they fall due before a brick is laid. Roughly £4,000 leaves the budget, which drops the sum to £46,000. That buys 14 to 20m² finished. At the £2,850 per m² midpoint of the London band, call it 16m².

Sixteen square metres is a real room. It’s a 4m by 4m rear extension, or a side return infill on a terrace that turns a dark galley kitchen into something you can eat in. It is not 30m², and it doesn’t come with landscaping.

Indicative split of a £50,000 extension budget, South London, September 2026. Build rate at the £2,850 per m² midpoint of the HomeOwners Alliance 2026 London range of £2,300 to £3,400 per m². Planning fee from the Planning Portal schedule, from 1 April 2026. Party wall figure from HomeOwners Alliance (2026), engineer from StructuralEngineerCalcs (2026). Indicative, not a quote.

Roughly £4,000 leaves the budget before the builder starts

None of the per-square-metre rates include statutory or professional fees. They’re your direct cost, and they’re payable at design stage rather than out of the final payment.

Here’s the stack. A householder planning application in England is £548 from 1 April 2026, though most South London rear extensions fall under Permitted Development and avoid it. Building control, the council’s check against Building Regulations, runs £600 to £1,320 plus VAT depending on floor area and borough. A party wall award with a single agreed surveyor is around £1,000, and a structural engineer for a straightforward rear extension is £550 to £900.

Added up, that’s roughly £4,000 at the top end. It sits inside the £3,000 to £6,000 range that fees typically occupy on a South London job.

Two of those lines can move against you. A mid-terrace with neighbours both sides can need more than one party wall award. An L-shaped or wraparound design pushes the engineer’s fee to £1,200 to £1,500 (StructuralEngineerCalcs, 2026).

This is general guidance and your property may differ. Check your own borough’s building control charges, and speak to a party wall surveyor about your specific boundary before you fix a budget.

Each of those fees, what triggers it and when it lands is broken down in the costs nobody quotes you.

The kitchen is a separate £20,000 line, not part of the build rate

This is the single most common reason a £50,000 extension ends up costing £70,000. The build rate buys a finished, decorated, wired and plastered room. It does not buy the kitchen you’re extending in order to get.

Architecture for London puts a new kitchen at £15,000 to £40,000 in 2026, and a bathroom at £5,000 to £10,000. Take about £20,000 as a working figure for a decent mid-range kitchen. Add it to £50,000 and you’re at £70,000 before anyone mentions landscaping.

So you have a choice to make early, and it’s better made on paper than on site. Build 16m² and fit the existing kitchen into it. Build smaller and fit a new kitchen. Or raise the budget.

Five things push a £50,000 extension over its budget

Almost every overrun on a project this size comes from the same short list. None of them is the builder being unreasonable. Four of the five are decisions you can make differently at design stage.

• Glazing spans. A 3m sliding door and a 5m sliding door are not the same purchase. Wider openings need bigger steels, deeper foundations at the padstones and more crane or manual handling on a tight South London site.
• Steels. Removing the rear wall of a terrace to open the kitchen into the extension is a structural job, not a cosmetic one. Every additional opening adds a beam, and every beam adds engineer’s calculations.
• Drainage diversion. Diverting a drain costs £1,500 to £5,000, and relocating a manhole £2,000 to £4,500 (StructuralEngineerCalcs, 2026). Victorian and Edwardian terraces routinely have both under the proposed footprint. A CCTV drainage survey before you agree a price costs far less than finding out in week three.
• Kitchen and finish specification. Moving from a mid-range kitchen to the top of the Architecture for London 2026 range adds £20,000 with no change to the building at all. Flooring, joinery and ironmongery drift the same way.
• Ground conditions. Shallow foundations, made ground, clay and nearby tree roots all push foundation depth beyond the assumption in an early price. This is the one line you can’t design away, so hold a contingency for it.

Three routes add usable space for less, each with a real trade-off

If £50,000 doesn’t stretch to the extension you actually want, changing the route is often better than shrinking the plan. Three options genuinely cost less, and each one costs you something other than money.

A garage conversion runs £8,500 to £20,000, averaging £14,250 (HomeOwners Alliance, 2026), and often falls under Permitted Development. You gain a warm room without touching the garden or the drains. The trade-off is orientation and light. A north-facing former garage with one small window can end up as the room nobody sits in.

A loft conversion runs £27,500 to £75,000, with a dormer averaging £50,000 (HomeOwners Alliance, 2026). You’re buying a room inside a volume you already own, and you keep the whole garden. The trade-off is the staircase, which eats floor area on the landing below, and the fact that a loft adds a bedroom rather than fixing a cramped ground floor.

A shell-only build runs £1,300 to £1,900 per m² excluding VAT (StructuralEngineerCalcs, 2026), well below the finished London rate. You get a watertight, structurally complete box now, and plaster, second-fix electrics and floor finishes when the money returns. The trade-off is worth stating plainly. You’ll live with an unfinished room for a year or two, and you need a builder who’ll price and programme both phases honestly.

Staging a build this way is a legitimate strategy, not a failure of planning.

If a loft is on your shortlist, we compare the two routes side by side in loft conversion or extension.

Sometimes the layout is the constraint, and £50,000 is the wrong question

Before you ask whether £50,000 is enough, check whether more floor area is what your house actually needs. Plenty of South London homes have the space already and simply have it in the wrong arrangement.

The signs are recognisable. A dark middle room nobody uses. A hallway that swallows four square metres to serve one door. A kitchen at the front of the house with the garden at the back. A dining room kept for guests twice a year.

Reconfiguring an existing footprint costs a fraction of extending it, because there are no foundations, no new roof and no drainage connections. It also carries no party wall notice in most cases, though that depends on whether you touch a shared wall.

Here’s the question worth asking before you divide any budget by any rate. What will this room be like at 7pm on a Tuesday in February, with homework on the table and dinner cooking? A well-planned 16m² that answers that beats a poorly planned 25m² that doesn’t.

If you do need more area than £50,000 buys, see what a 20, 30 and 40m² extension costs with fees included.

What to do next

Work backwards from the fees, not forwards from the build rate. Take roughly £4,000 off your £50,000, divide what’s left by £2,300 to £3,400 per m², and you have a defensible floor area to design to. Then decide, in writing, whether the kitchen is inside the budget or outside it.

Spend the design time before the build time. The rate per square metre is broadly set by the market. Whether those square metres are worth £50,000 is entirely down to the plan.

If you’d like this arithmetic tested against your actual house, Rapid Bee covers Bromley, Bexley, Greenwich, Lewisham and Southwark, and will talk through a realistic range before any drawings exist.

Frequently asked questions

* All figures on this page are indicative for South London as at September 2026 and are not a quote. Costs move with ground conditions, specification, site access and season. Regulatory guidance here is general; your property may differ, so confirm your position with your local authority or a party wall surveyor before committing.

A dark galley kitchen, a missing fourth bedroom and nowhere quiet to work are three different problems. They point to three different builds. Start with the complaint and the format usually picks itself.

This guide covers every format worth considering on a South London house: single-storey, rear, side return, wraparound, kitchen, double-storey, loft, garage, orangery and basement. For each one you get what it does to the plan, what it takes away, and what it costs in indicative 2026 terms. For the full cost mechanics, see our breakdown of house extension costs in South London.

The Short Answer

• The format follows the problem. Width, depth, bedrooms and a quiet room are four different briefs with four different answers.
• Ground-floor formats buy width, depth and light. They all cost you garden, and some cost more garden than they’re worth.
• Loft conversions and double-storey extensions add bedrooms without touching the garden at all.
• Garage conversions and basements both use land you already own, at opposite ends of the difficulty scale.
• Indicative London single-storey build costs run £2,300 to £3,400 per m² (HomeOwners Alliance, 2026), with £3,000 to £6,000 of fees sitting outside that rate.
• Most South London rear extensions fall under Permitted Development, but conservation areas and Article 4 directions remove those rights street by street.

Start with the problem you’re solving, not the format you like the look of

Pick the goal first. Every format below is good at something and bad at something else, and the mismatch is what produces regret.

Write your goal down in one sentence before you talk to anyone. If you can’t, the drawings will drift toward whatever is easiest to build.

Six decisions do most of the work on any extension

Whichever format you choose, the same six questions decide whether you like the result. They come up on every project, in roughly this order.

Light and flow are the two people underestimate most. Floor area is easy to picture, so it gets the attention, while the route from the back door to the bins gets none. That imbalance is behind most of the layout complaints we hear after handover.

A single-storey extension is your chance to replan the whole ground floor

A single-storey extension pushes the back or side of the house out at ground level. That’s the obvious part. The useful part is that once the rear wall comes down, every room on that floor is available to rethink.

Most people push the wall out and keep the internal doors exactly where they were. That buys floor area and keeps the old bottlenecks. Moving the stairs cupboard, repositioning a doorway or relocating the WC often does more for daily life than the last metre of depth.

It works when you want a bigger kitchen or a family room that opens to the garden. It works badly when the garden is already small, or when the site slopes enough to need retaining work.

Many single-storey rear extensions fall under Permitted Development, subject to depth limits and conditions. Rooflights and wide glazed doors are what keep the middle of the plan from going dim.

Where each format adds space on a typical South London two-storey house. Diagram by Rapid Bee, 2026, for illustration only and not to scale.

A rear extension is judged on how it meets the garden

A rear extension runs across the back of the house and faces the garden. Everything good about it depends on the join between inside and out.

Three details do most of that work. Match the internal floor level to the external paving so the threshold is level and step-free. Use the same or a similar floor finish on both sides of the glass. Align the roof drainage so gutters and downpipes don’t cut across the view.

Get those right and the garden reads as another room. Get them wrong and you’ve built a glazed wall with a step in front of it.

Wide sliding or bi-fold doors are the usual choice. Sliders give you bigger panes and slimmer frames when shut, which matters because the doors stay shut for most of the British year.

A side return buys width a terrace cannot get any other way

A side return fills the narrow alley beside the rear outrigger of a Victorian or Edwardian terrace. It typically adds around 2m of width to a room that has never had enough.

That width is what turns a galley kitchen into a room with a table in it. It costs you almost no garden, because the alley was already a dead strip where the bins lived.

The catch is daylight. The infilled space has walls on both sides and no external wall of its own, so roof glazing isn’t decoration. Without rooflights you’ve built a wider dark kitchen.

You’re also building at or near the boundary, so notices under the Party Wall etc. Act 1996 are almost always required. Serve them early and talk to the neighbour before the paperwork arrives.

We combined a rear and side return on a terrace at George Lane, SE13, and built a rear extension at Bushey Way in Beckenham. Both show what the width and the glazing actually buy you.

A wraparound suits corner and end-of-terrace plots

A wraparound joins a side return to a rear extension in an L around the back of the house. It produces the largest open ground floor of any format on a standard terrace.

It also steps up every cost at once. Longer steels to carry the corner, deeper foundations, and drainage that usually crosses the new footprint. Party wall exposure typically moves from one neighbour to two.

Choose it when the whole ground-floor plan is the problem, not just the kitchen. If a side return alone gives you a kitchen and dining space that works, the extra rear depth buys little. Usually it buys a darker middle of the house and a shorter garden.

End-of-terrace and corner plots suit it best, because there’s genuine width to wrap into rather than a single narrow alley.

A kitchen extension is a function upgrade wearing a floor-area disguise

A kitchen extension isn’t a separate structure. It’s a single-storey rear or side return brief written around how the kitchen gets used.

Think in three zones. Preparation, where the sink, hob and worktop sit. Dining, where the table goes and where the chairs need room to pull out. Social, where people stand, sit and get in the way.

The most common failure is a large kitchen bolted onto a small sitting room. You end up with a huge cooking and dining space and nowhere comfortable to sit in the evening. Draw both rooms, not just the new one.

While the walls are open, run the new electrics and plumbing as one exercise rather than in stages. Sockets, lighting circuits, extraction and waste runs are far harder to change once the plaster is on.

A double-storey extension spreads one set of foundations across two floors

A double-storey extension adds ground-floor and first-floor space in a single build. The foundations, roof, scaffolding and site setup serve both levels, so the second floor carries a lower share of those fixed costs than the first.

You’ll hear a specific percentage quoted for the uplift over a single-storey build. We’re not repeating one, because we haven’t found a figure with a published method behind it. Price it as two floors of build area plus the extra structural work.

It almost always needs a full householder planning application rather than Permitted Development. Height, depth and the effect on neighbouring windows all get scrutinised.

One practical design point saves real money. Stack the new bathroom directly above or below an existing one so the waste and supply runs share a route. Misaligned wet rooms mean longer pipe runs and more structural fuss.

A loft conversion adds bedrooms without taking any garden

A loft conversion turns unused roof space into habitable rooms. It’s the obvious answer when you need bedrooms, a study or a guest suite and the garden is already doing a job.

Head height decides whether it’s straightforward. Around 2.2m of clear height between the ceiling joists and the ridge is the workability rule of thumb the trade uses. It is not a legal threshold. England sets no statutory minimum ceiling height for a loft conversion, and Building Regulations govern the staircase, fire escape route and structure instead.

Below that rough mark you’re into lowering ceilings or raising the roof, and the job changes character. A dormer, which is a box built out from the roof slope, is the usual way to add standing room. A mansard rebuilds the roof at a steeper pitch and gives the most space, with the heaviest planning and structural load.

Indicative UK costs run £27,500 to £75,000, with a dormer conversion averaging about £50,000 (HomeOwners Alliance, 2026). These are indicative 2026 figures, not quotes.

A garage conversion is the shortest route to one extra room

Converting an integral garage gives you a home office, gym or spare room without altering the footprint of the house. If you don’t need the parking, it’s the least disruptive option on this list.

Most garage conversions fall under Permitted Development when the work stays inside the existing structure. Building Regulations still apply in full, covering insulation, ventilation, fire safety and the new floor build-up.

Two details separate a proper room from a converted garage. Insulate the floor, walls and roof to current standards rather than the bare minimum. Then raise the floor so it meets the level of the rest of the house. A step down into a cold room is what makes these conversions feel like an afterthought.

Indicative UK costs run £8,500 to £20,000, averaging about £14,250 (HomeOwners Alliance, 2026). Losing off-street parking is the real trade-off, and on some South London streets that matters to buyers.

An orangery holds its temperature in a way a conservatory doesn’t

A conservatory is mostly glass, including the roof. It goes up quickly and costs less than a masonry extension, which is genuinely why people choose it. The trade-off is that it overheats in July and loses heat in January, so it drops out of use for months at a time.

An orangery has solid brick piers, a proper insulated roof and usually a central roof lantern. It reads as part of the house rather than something attached to it, and it stays comfortable across more of the year.

If the room needs to work as everyday family space, the orangery is the format that delivers it. If you want a light garden room you’ll use in spring and summer, a conservatory is an honest answer at a lower price.

Both sit under the same regulatory questions as any other extension. Check Permitted Development limits and Building Regulations before assuming a glazed structure is exempt.

A basement is the hardest option, and belongs at the bottom of the shortlist

A basement extension creates new floor area beneath the house or the garden. It’s used for cinema rooms, gyms, guest bedrooms and storage, and it appeals where the plot is tight and above-ground change is restricted.

Technically it’s the most demanding format here. The existing foundations usually need underpinning, which means extending them downward in short sections while the house stays standing. Waterproofing is then designed as a whole system. That means either tanking, a sealed barrier applied to the structure, or a cavity drain membrane. A membrane is a studded lining that collects water behind it and pumps it away.

Disruption is high and the programme is long. Excavated spoil has to leave a residential street by grab lorry, and the structural work happens beneath a house you’re still living in.

It earns its place when there’s genuinely no other route to the space. On most South London family homes, a loft or a ground-floor extension answers the same brief for far less risk.

Light and the garden connection separate excellent projects from average ones

This is the theme that divides the projects people love from the ones they merely tolerate. Extra depth in a plan is exactly what pushes daylight away from the centre of the house.

Side return and wraparound formats carry a particular risk. They can block existing windows and move living space further from any external wall. The middle of the plan then relies entirely on borrowed light.

Five counters work reliably. Rooflights or a lantern over the deepest part of the plan. Glazed internal partitions that pass light between rooms. A double-aspect layout so key rooms get light from two directions. An internal courtyard or light well on deep plots. And higher ceilings, which let light reach further in.

The garden connection needs the same deliberate treatment. Large glazed doors, a consistent floor finish inside and out, a level threshold, and the dining area positioned to face the garden rather than a wall. Add some shelter, a deep reveal or a canopy, so the space is usable when the weather isn’t perfect.

What each format is likely to do for resale, stated honestly

Some changes reliably broaden the pool of buyers. An extra bedroom does it, particularly when it moves the house across a bracket from two to three or three to four. Additional bathrooms or an en-suite do it. So do flexible living space connected to the garden, a utility room, real storage and a workable home office.

You’ll see confident percentage uplifts attached to each of these. Treat them with care. The widely repeated figures trace back to estate agency marketing rather than a published dataset with a stated method, so we don’t publish them as fact.

Five choices work against resale. Sacrificing the entire garden. Removing off-street parking on a street where it’s prized. Creating a room reachable only by walking through another bedroom. Building an over-specialised space that suits one hobby. And finishes that visibly ran out of money.

A balanced, well-lit layout usually beats maximum floor area. Buyers respond to how a house feels to walk through, and a dark, deep plan feels smaller than its square metres suggest.

The standard framing treats value as a function of added area, which is why homeowners default to the largest format their plot allows. The failure modes listed above are all layout failures rather than size failures, which means value is set at the drawing stage by circulation, daylight and bedroom count, not by the build rate. Observation drawn from completed South London projects rather than a measured dataset.

Planning in South London depends on your borough and your street

Most rear extensions on South London family homes fall under Permitted Development. That’s the starting position, not a guarantee, and the exceptions are common enough to check before anything is drawn.

Bromley, Bexley, Greenwich, Lewisham and Southwark each publish their own householder design guidance. Conservation area status is common across the terraced streets of Greenwich, Lewisham and Southwark, and it removes side extension rights entirely. An Article 4 direction can withdraw Permitted Development rights elsewhere, street by street, at the borough’s discretion.

Two national limits come up on almost every job. Depth allowances for single-storey rear extensions, and the rule that a side extension can be no wider than half the width of the original house. “Original” means the house as it stood on 1 July 1948, or as first built if later.

If you’re relying on Permitted Development, apply for a Certificate of Lawfulness. It’s a formal confirmation from the council that the work is permitted, and it’s the document a buyer’s solicitor will ask for later. This guidance is general and your property may differ, so confirm your position with your local authority or a party wall surveyor.

Recurring pattern across projects in Bromley, Bexley, Greenwich, Lewisham and Southwark. Homeowners arrive with a design already drawn and treat planning as a submission step rather than a design constraint. Completed projects including George Lane in SE13 and Bushey Way in Beckenham sit behind this observation. Pattern from project records, not a measured dataset.

What these formats cost in indicative 2026 terms

Build rates vary by format, and the fees outside the build rate vary hardly at all. Here’s what the published sources say.

Every figure above is indicative for the geography and year stated. None of them is a quote.

The fee band breaks down into four items. A householder planning application in England costs £548 from 1 April 2026. Building control runs an indicative £600 to £1,320 plus VAT. Party wall costs sit at around £1,000, rising if neighbours appoint their own surveyors. A structural engineer runs £550 to £900 for straightforward work. Each one is set out, with what triggers it and when it falls due, in the costs nobody quotes you.

Three things move the build rate within its range. Structure, because fewer and shorter steels cost less. Access, because a tight terrace means barrowing material through the house. And specification, because glazing, joinery and finishes are where budgets quietly expand. Hold 10% to 15% back as contingency on any format. To see how the all-in cost moves with floor area, see what a 20m², 30m² and 40m² extension costs.

Match your situation to a format

This grid is the short version of everything above. Find the row that sounds like your house.

If two rows describe you, draw both options before committing. The comparison usually settles it faster than another conversation about budget.

Where to take this next

Write down the problem in one sentence, then pick the two formats that answer it. Draw both at sketch level before you talk about budget. The comparison tells you more in an afternoon than weeks of price gathering.

Then check the constraints early. Conservation area status, Article 4 directions and party wall obligations all shape a design. Accommodating them at sketch stage costs far less than reworking drawings you’ve already paid for.

When you’re ready to put numbers to it, work from ranges with a date and a geography attached. Our South London extension cost breakdown sets out the build rates and the fees that sit outside them. If you’d like to talk through which format suits your house, we’re happy to have that conversation before any drawing exists.

Frequntly asked questions about types of house extensions

This page gives you the current rates, names the publisher and date behind each one, and then adds the fees that the rates leave out. It also shows what the finished space will be like to live in. A 30m² extension you regret costs exactly the same as a 30m² extension you love.

If you haven’t settled on a format yet, start with our guide to the types of house extensions and come back here for the numbers.

The Short Answer

• A single-storey extension in London costs £2,300 to £3,400 per m² to build (HomeOwners Alliance, 2026). The same publisher puts the UK figure at £1,800 to £3,000 per m².
• Fees outside that rate add roughly £3,000 to £6,000. That’s a £548 planning application in England from 1 April 2026, plus £600 to £1,320 plus VAT for building control. Add around £1,000 for a party wall award and £550 to £900 for a structural engineer. Architect fees sit outside this band.
• A 30m² rear extension in South London realistically lands at £75,000 to £105,000 all in, excluding a new kitchen.
• A two-storey extension costs less per square metre than a single-storey one, at around £1,900 per m² (HomeOwners Alliance, 2026), because the foundations and roof are shared across two floors.
• £50,000 buys roughly 14 to 20m² finished at London rates once fees are paid. Enough for the box, rarely the box and a new kitchen inside it.
• Moving instead isn’t free. Stamp duty alone on a £700,000 South London family home is about £25,000 on the GOV.UK residential rates.

All figures are indicative for South London as at September 2026, not a quote. Your property, ground conditions and specification will move them.

A South London extension costs £2,300 to £3,400 per square metre to build

That’s the London single-storey range published by the HomeOwners Alliance in 2026. The same organisation puts the UK-wide figure at £1,800 to £3,000 per m². Because both numbers come from one publisher using one method, the comparison is like for like, which is rare in this market.

Treat that London band as a finished builder’s contract: structure, roof, glazing, plaster, electrics, plumbing, decoration. It does not include your professional fees, your statutory fees, or your kitchen.

Other credible publishers sit around it rather than on it. Architecture for London quotes £3,000 to £5,000 per m² in 2026 for architect-designed work in London, excluding VAT and professional fees, with professional services adding a further 15 to 20%. That is a wider basis than the architect-only figure in the fee table below.

StructuralEngineerCalcs gives £1,900 to £3,300 per m² excluding VAT for single-storey work, and £1,300 to £1,900 per m² for a shell only. The Federation of Master Builders published £1,800 to £3,000 per m² for single-storey extensions in 2026.

Four different products, not four opinions about one product. Sources: shell only and ex-VAT single-storey rates, StructuralEngineerCalcs (2026); UK and London finished build rates, HomeOwners Alliance (2026); London architect-designed rate, Architecture for London (2026), which excludes VAT and professional fees. Indicative, not a quote.

Most cost guides average competing per-m² rates into a single range. Separating them by product (shell / finished contract / architect-designed with fees) explains the spread instead of hiding it, and lets a reader place their own quote on the scale.

The spread exists for four reasons, and none of them is one builder being greedy

If you’ve collected three quotes and they’re £30,000 apart, the gap is usually explainable. Four things drive almost all of it. Scope. Geography. VAT. Old figures still in circulation.

Scope: shell, finished contract and architect-designed are three different purchases

A shell at £1,300 to £1,900 per m² (StructuralEngineerCalcs, 2026, excluding VAT) gives you a watertight, structurally complete box. No plaster, no second-fix electrics, no floor finish. A finished builder’s contract at £2,300 to £3,400 per m² in London (HomeOwners Alliance, 2026) hands you a decorated room. Architect-designed work at £3,000 to £5,000 per m² (Architecture for London, 2026) carries design development, drawings and tighter detailing.

StructuralEngineerCalcs breaks its own range into three specification tiers, excluding VAT: Basic £1,900 to £2,200 per m², Standard £2,200 to £2,700, Premium £2,700 to £3,300.

The difference is glazing, joinery, floor finishes and ironmongery, not structure. Build method shifts the figure separately, which we compare in timber frame versus brick.

Geography: London runs about 19% above the UK midpoint

Compare the HomeOwners Alliance 2026 figures directly. UK £1,800 to £3,000 per m², midpoint £2,400. London £2,300 to £3,400 per m², midpoint £2,850. That’s roughly 19% at the midpoint, from one publisher using one method.

You’ll see a “20 to 40% London premium” widely cited across the industry. We’d treat it with care, because the same figure is restated on many sites without a traceable origin. The like-for-like comparison above is the more defensible number.

VAT: 20% moves a quote a whole band without changing anything

This catches more people than any other line. A £2,500 per m² rate quoted excluding VAT is £3,000 per m² including it. That lands inside the “architect-designed” band with no change to the specification at all.

Most published trade rates exclude VAT. Most homeowner guides quote including it. Before you compare two numbers, check which one you’re holding. Ask the question in writing.

Stale figures: the planning fee some guides still publish is out of date

The householder planning application fee in England is £548 from 1 April 2026. It was £528 from 1 April 2025, and £258 before that. Several widely-read cost guides still show £258.

That’s a £290 error in a homeowner’s spreadsheet, and it’s the easiest one to check. The fee is set nationally through the Planning Portal fee schedule, published by government, and no council can discount it. Fees are uprated each April, so check the current schedule before you budget.

A two-storey extension costs less per square metre than a single-storey one

This is the most useful counter-intuitive fact in extension costing. The HomeOwners Alliance puts two-storey work at around £1,900 per m² in 2026. That’s near the bottom of its own £1,800 to £3,000 UK single-storey range, and well below its £2,300 to £3,400 London range.

The reason is structural, not commercial. Foundations, groundwork, drainage connections and the roof are the expensive parts, and a two-storey extension shares all of them across twice the floor area. The first floor is essentially walls, joists, glazing and finishes.

That doesn’t make two storeys the right answer. It costs more in total, it’s far more likely to need full planning permission, and it affects your neighbour’s daylight in a way a single storey usually doesn’t. But if you’re choosing between 25m² over one floor and 40m² over two, the per-square-metre maths may surprise you.

Fees outside the build rate add roughly £3,000 to £6,000

None of the per-square-metre rates above include statutory or professional fees. Budget for them as a separate line from day one, because they fall due before a single brick is laid.

The £6,000 top is not the straightforward case. Take the top of every statutory and engineering line above: £548 planning, £1,584 building control with VAT, a £2,700 party wall award and a £1,500 wraparound engineer. That reaches about £6,330, which is where the £6,000 comes from. The £2,700 is the top of the agreed single-surveyor range. A contested award with two surveyors runs £1,800 to £5,400. At the top of that range the fee total passes £9,000, well outside this band.

The £3,000 floor is the other end of the same table, not the same job priced twice. Take £548 planning, £1,008 building control with VAT on the 10 to 40m² band, a £900 party wall award and a £550 engineer. That reaches £3,006.

The top is a 60 to 100m² wraparound and the floor a 10 to 40m² rear extension. A sub-10m² job at £720 building control sits below this band entirely, and Permitted Development takes you lower still, because the planning fee drops to a £274 certificate.

Architect fees sit outside this band, because they scale with build cost rather than with paperwork. At 15% of an £85,000 build that is £12,750 on its own, which is more than the whole fee band above. Budget it as a separate line.

Note the two architect bases differ. The 3% to 15% above is the architect alone, while Architecture for London’s 15% to 20% covers professional services as a whole.

Each of these fees is taken one at a time, with what triggers it, who invoices you and when it lands, in the hidden costs of a house extension.

Most South London rear extensions don’t need planning permission at all

Permitted Development is the right that lets you build certain extensions without a planning application. Most single-storey rear extensions on South London semis and terraces fall under it, which is why the planning fee is often the one cost you avoid.

Three things commonly remove that right. A conservation area. An Article 4 direction, which is a council order withdrawing Permitted Development for a defined area. And a previous extension that has already used up your allowance.

Even under Permitted Development, a Lawful Development Certificate is worth buying. It’s a formal council confirmation that your build is legal, at half the full application fee, and your buyer’s solicitor will ask for it in ten years’ time.

This is general guidance and your property may differ. Check with your own borough before you commit.

Building control in Bromley and Bexley runs £600 to £1,320 plus VAT

Building control is the council’s check that the work meets Building Regulations, the national standards covering structure, insulation, fire safety, ventilation and drainage. It’s a separate service from planning, with a separate fee, and you cannot skip it.

The charge depends on floor area and varies by borough. Bromley’s 2026 schedule, excluding VAT, runs in paired charges by floor area. Up to 10m² is £300 plus £300, and 10 to 40m² is £420 plus £420. For 40 to 60m² it’s £510 plus £510, and for 60 to 100m² it’s £660 plus £660. The two halves are the plan check and the site inspections; the building notice route is charged as the combined figure.

Bexley increased its charges on 20 April 2026. Up to 10m² is now £640 excluding VAT, up from £591. The 10 to 40m² band is £800, up from £792, and 40 to 60m² is £960, up from £886. Those are the plan and inspection charges on the full plans route, each figure the sum of the two charges on the council’s comparison table. Bexley’s regularisation charges for work already built are higher again, and are not what a normal job pays.

Building control charges excluding VAT, by floor area. Bromley figures are the combined plan check and inspection charge from bromley.gov.uk (2026). Bexley figures are the plan and inspection charges on the full plans route that took effect on 20 April 2026, from bexley.gov.uk. Both councils publish higher regularisation charges for work already built; those are excluded here. Indicative, not a quote.

The kitchen is the segment people forget. Architecture for London puts a kitchen at £15,000 to £40,000 and a bathroom at £5,000 to £10,000 in 2026. Choose the top of that kitchen range and your £108,000 job becomes £128,000, with no change to the building at all.

We build in these boroughs and publish the jobs. A part-single, part-two-storey side and rear extension at Wilderness Road in Chislehurst ran from May to September 2023, after a detached garage came down to make room for it. Single-storey rear and side extensions at Woodyates Road in Lee came with a full ground-floor refurbishment. We do not publish those clients’ contract values, so treat the ranges here as the market rather than as our quote.

Is £50,000 enough for a house extension in South London?

£50,000 buys a finished extension of roughly 14 to 20m² in South London once fees are paid, excluding a new kitchen. Call it 16m² at the mid-range rate. That’s a useful single room. It is not a kitchen-diner with bifolds.

The arithmetic is straightforward. At the HomeOwners Alliance 2026 London rate of £2,300 to £3,400 per m², £50,000 of pure build buys 15 to 22m². Then take out the fees. The £548 planning application if you need one, and £840 plus VAT for building control, which is Bromley’s 10 to 40m² band for a job this size. Then around £1,000 for a party wall award and £725 for a structural engineer, the midpoint of the £550 to £900 range. Roughly £3,280 comes off the top.

That’s the same fee basis as the 30m² worked example above. The £6,330 figure earlier on this page is a larger job: the 60 to 100m² building control band, the top of the agreed single-surveyor range and a wraparound engineer. £3,280 is also the figure the £30,000 answer below is built on.

What £50,000 does well: a decent-sized single room, a side return infill on a terrace, or a shell you fit out later. What it doesn’t do: 30m², a new kitchen and landscaping.

The full arithmetic, and what to do if £50,000 falls short, is in is £50,000 enough for an extension.

Can you extend for £30,000?

At the bottom of the London range, £30,000 buys about 12m² once fees are paid, which is a small utility or study rather than a living space. On the build rate alone it looks like 13m², but that is the one basis this page tells you not to budget on. For most South London homeowners there are two better uses of that money.

The first is a garage conversion. The HomeOwners Alliance puts these at £8,500 to £20,000 in 2026, averaging £14,250, and they often fall under Permitted Development. You gain a warm, usable room without touching the garden or the drains.

The second is a shell-only build at £1,300 to £1,900 per m² excluding VAT (StructuralEngineerCalcs, 2026), fitted out over the following year or two. At those rates, £30,000 puts up a substantially larger structure than £30,000 of finished work. Plaster, flooring and joinery follow when the money does.

Staging a build like that is a legitimate strategy, not a failure. It does need a builder who will price and programme it honestly, and it does mean living with an unfinished room for a while.

A 30m² extension costs £75,000 to £105,000 all in

That’s the realistic South London all-in figure for a single-storey rear extension of 30m² in 2026, including professional and statutory fees but excluding a new kitchen. Here’s where it comes from.

That bottom row is the £69,000 to £102,000 London band plus this page’s £3,000 to £6,000 of fees, which gives £72,000 to £108,000. It is trimmed inward at both ends because the extremes of the two bands rarely coincide. The jobs that hit the top build rate are not usually the jobs that incur the highest party wall and engineer fees.

The HomeOwners Alliance also publishes bands for other sizes: 20m² at £40,000 to £56,000 and 50m² at £100,000 to £140,000. Those are UK figures, so add the London uplift discussed above before you use them.

For 20m² and 40m² priced on the same London basis as this 30m² example, see what a 20m², 30m² and 40m² extension costs.

The least expensive ways to add space, ranked

Garage conversion first, then loft, then a single-storey rear extension under Permitted Development, then a shell-only build. Here they are with the numbers attached, lowest cost first. If a growing family is the driver rather than a budget ceiling, our guide to the best extensions for growing South London families ranks them differently.

1. Garage conversion: £8,500 to £20,000, average £14,250 (HomeOwners Alliance, 2026). No new foundations, no new roof, often no planning application.
2. Loft conversion: £27,500 to £75,000 and up, with a dormer averaging £50,000 (HomeOwners Alliance, 2026). You’re buying a room inside a volume you already own.
3. Single-storey rear extension under Permitted Development. At £2,300 to £3,400 per m² in London you’re paying full rates, but you avoid the £548 application fee and several months of uncertainty.
4. Shell-only build at £1,300 to £1,900 per m² excluding VAT (StructuralEngineerCalcs, 2026). Lowest rate on the board, but the fit-out cost is deferred, not removed.

Best value isn’t the same as lowest price. A £14,250 garage conversion that gives you a cold, north-facing room nobody uses is worse value than a £70,000 extension the family lives in every day.

Victorian and Edwardian terraces carry costs that newer houses don’t

South London’s terrace stock brings two cost risks that rarely appear in national guides: drains under the footprint, and a manhole in the middle of your new floor. Both are common on pre-1940 properties with rear additions.

Diverting a drain runs £1,500 to £5,000, and relocating a manhole £2,000 to £4,500 (StructuralEngineerCalcs, 2026, a single trade source not yet corroborated elsewhere). Neither is optional once you find one. A CCTV drainage survey before you agree a price is far less painful than a variation halfway through.

Older terraces also tend to have shallow foundations, which can mean underpinning at the party wall, and lime mortar that behaves differently from cement. Add a mid-terrace position with neighbours both sides, and your party wall costs can double.

One more practical point. A skip on a South London street needs a permit from the borough, and on a narrow terraced road you may not get a bay outside the house at all. Ask how your builder plans to handle waste and deliveries before work starts.

Moving instead costs about £25,000 in stamp duty before you’ve packed a box

Stamp Duty Land Tax on a £700,000 South London family home is about £25,000 on the GOV.UK residential rates for a main home. Nothing to £125,000. Two per cent on the slice from £125,000 to £250,000, which is £2,500. Five per cent on the slice from £250,000 up to the £700,000 purchase price, which is £22,500. Statutory rates checked September 2026; published November 2026.

That’s a pure transaction cost. It buys you no floor area, no light and no storage. Add estate agent fees, conveyancing, survey and removals on top, and the gap widens further.

Set against the numbers above, £25,000 is roughly a quarter to a third of the all-in cost of a 30m² extension. If you’re staying in catchment and you like the street, the maths usually favours extending. If the house has a structural problem money can’t fix, it doesn’t.

Design decides whether the money was well spent

The most expensive mistake in an extension isn’t the build rate. It’s spending £90,000 to create a space that doesn’t work for how your family actually lives, which costs the same as spending £90,000 on one that does.

Across the UK homeowner forum threads we reviewed, the same regrets recur, and they’re almost never about size. These are self-selected posts of unverified date drawn from Mumsnet threads, not a survey. No utility room, so the washing machine runs in the middle of a kitchen-dining-living space. A huge kitchen and a lounge that stayed small. Open plan that can’t contain cooking smells. Heating bills on a large open volume nobody costed.

The keepers recur too: plenty of glazing, rooflights, and insulation specified above the Building Regulations minimum. Rooflights in particular do something side windows can’t, which is bring daylight into the middle of a deep plan without overlooking a neighbour.

Ask one question before you sign anything. What will this room be like at 7pm on a Tuesday in February, with homework on the table and dinner cooking? If the plan can’t answer that, more square metres won’t help.

How to compare three quotes that look nothing alike

Put all three on the same basis before you compare a single number. Most quote gaps close once you do, and the ones that don’t are telling you something useful. The same discipline applies to the build itself, and we have written up the ten mistakes that cause the most expensive surprises.

Ask each builder the same five questions in writing:

• Does the price include VAT? A 20% difference explains most apparent gaps.
• What’s excluded? Kitchen, flooring, decoration, landscaping and the structural engineer are the usual absentees.
• Who pays the statutory fees? Planning, building control and party wall are often the homeowner’s direct cost.
• What’s the provisional sum for groundworks and drainage? On a Victorian terrace this is where variations come from.
• What’s the payment schedule tied to? Stages of completed work, not calendar dates.

At Rapid Bee we price extensions this way because it’s the only way a homeowner can compare fairly, and because the alternative is a variation conversation in week six. A quote that looks lower because it quietly excludes £8,000 of work isn’t a lower quote.

An online calculator multiplies floor area by an average rate, so it gives you the build contract and nothing else. It won’t know your drainage, your borough’s building control charge, your party wall position or your specification. Treat the output as the first line of a budget, not the total.

Work out the floor area you need, then apply the London rate of £2,300 to £3,400 per m². Add £3,000 to £6,000 of statutory and engineering fees, a separate line for any architect, and another for the kitchen. That gives you a budget you can defend when quotes arrive. When you want it tested against a real design, that is what our house extensions service does.

Then spend the design time before the build time. The cost per square metre is broadly fixed by the market. Whether those square metres are worth the money is entirely down to the plan.

All figures on this page are indicative for South London as at September 2026 and are not a quote. Costs vary with ground conditions, specification, site access and the time of year you build. Regulatory guidance here is general; your property may differ, so confirm your position with your local authority or a party wall surveyor before committing.

If you’d like these numbers tested against your actual house, Rapid Bee provides house extension services in South of London, including Bromley, Bexley, Greenwich, Lewisham and Southwark, so if you’re local, please contact us, and we’ll talk through a realistic range before any drawings exist.

Frequently asked questions

Pick the one that fixes the room you’re short of. Short of bedrooms, go up. Short of somewhere to cook, eat and sit together, go out. This page compares the two on cost, planning, Building Regulations and daily life, and names a third option most comparisons leave out.

For the full cost picture behind these figures, see our guide to house extension costs in South London.

The Short Answer

• A loft conversion runs £27,500 to £75,000, with a dormer averaging about £50,000 (HomeOwners Alliance, 2026). You gain bedrooms and keep the whole garden.
• A London single-storey extension runs £2,300 to £3,400 per m², against £1,800 to £3,000 across the UK (HomeOwners Alliance, 2026). A 20m² build is roughly £46,000 to £68,000.
• Fees of £3,000 to £6,000 sit outside the build rate on both routes. That’s £548 planning from 1 April 2026, £600 to £1,320 plus VAT building control, around £1,000 party wall and £550 to £900 structural engineer.
• A loft needs head height and the right roof. About 2.2m of clear height is the working rule of thumb, and a traditional cut roof converts more easily than a trussed one.
• A third storey triggers fire escape and protected stairway requirements under Part B of the Building Regulations. That’s the single biggest hidden cost driver on a loft.
• A garage conversion runs £8,500 to £20,000, averaging about £14,250 (HomeOwners Alliance, 2026), and is the least expensive route to a usable room.

All figures are indicative for South London as at September 2026 and are not a quote. Your property, roof structure and specification will move them.

A loft adds bedrooms, an extension adds the room everyone enjoys

The two routes change daily life in almost opposite directions, so start with how your household actually uses the house.

A loft conversion puts a bedroom, and usually a shower room, above the existing first floor. It relieves pressure on sleeping space and gives a teenager or a home worker somewhere separate. It does nothing for a cramped kitchen, and nobody carries laundry up two flights for fun.

A rear extension does the reverse. It widens or deepens the ground floor so the kitchen, dining table and sofa share one space that opens to the garden. That’s the room the family spends its evenings in. It’s also the part of the garden those evenings used to spill into in July.

So the honest test isn’t which adds more value. It’s which of those two shortages is making your house feel wrong.

On the loft conversions we’ve completed in South London, including Bushey Way in Beckenham and Woodyates Road, the brief that holds up over time is the one written around a specific sleeping or working problem, not around adding a room in the abstract.

Costs overlap more than most people expect

Neither route is reliably less expensive than the other. Their ranges sit on top of each other, so cost alone rarely decides it.

The HomeOwners Alliance puts a loft conversion at £27,500 to £75,000 in 2026, with a dormer conversion averaging about £50,000. The same source puts a London single-storey extension at £2,300 to £3,400 per m², against £1,800 to £3,000 for the UK as a whole. Multiply the London band by a typical 20m² and you get roughly £46,000 to £68,000 of build.

That £50,000 dormer and that 20m² extension sit close enough together that something else has to decide it. If £50,000 is your ceiling either way, see what £50,000 buys as a house extension.

Fees behave the same on both routes. Expect £3,000 to £6,000 outside the build rate. That covers £548 for a householder planning application from 1 April 2026, and £600 to £1,320 plus VAT for building control. Add around £1,000 for a party wall award and £550 to £900 for a structural engineer. We break each one down, with what triggers it, in the costs nobody quotes you.

The two routes compared line by line

Head height and roof type decide whether a loft is even possible

Measure before you cost anything. The working rule of thumb is about 2.2m of clear height, taken from the top of the existing ceiling joists to the underside of the ridge. You want that height across a useful share of the floor, not just at the peak. Below roughly 2.2m, the conversion gets expensive or stops being worth doing.

Treat that as a rule of thumb, not a regulation. England sets no statutory minimum ceiling height for a loft conversion. The 2.2m figure survives because a new floor structure and insulation eat into the void from both directions.

A cut roof converts more easily than a trussed roof

Look at what’s holding your roof up. A traditional cut roof, built on site from rafters, purlins and ceiling joists, leaves an open triangular void you can work inside. Most Victorian, Edwardian and interwar South London houses have one.

A trussed rafter roof is different. It uses prefabricated W-shaped frames, common in houses built from the mid-1960s onward, and those diagonal webs fill the space you want to occupy. Removing them means new steel beams and a new floor structure before you gain a single square metre. Real money, spent before the room exists.

The new staircase comes out of an existing first-floor room

This is the cost people forget, and it isn’t money. It’s floor area.

A loft staircase has to land somewhere on the first floor, and that somewhere is usually a corner of an existing bedroom or a widened landing. A straight flight plus its landing typically absorbs around 3 to 4m² of the floor below. You can gain a large loft bedroom and quietly lose a small one.

Headroom over the stair is governed too. Approved Document K asks for 2m of headroom above the pitch line, reduced to 1.9m at the centre and 1.8m at the side where the ceiling slopes. That’s what forces the stair into a particular position, not preference.

So test the first-floor plan before you fall in love with the loft plan. If the staircase turns a three-bedroom house into a house with two proper bedrooms and a loft, the sums change.

Most loft-versus-extension comparisons price the room being added and ignore the room being reduced. Netting the 3 to 4m² lost to the staircase against the loft gained is the calculation that decides whether a loft actually improves the bedroom count.

Permitted Development treats lofts and extensions differently

Both routes carry Permitted Development rights, meaning you can often build without a full planning application. The allowances are measured in completely different units, which trips people up.

For lofts, the limit is volume. Permitted Development allows up to 40m³ of extra roof space on a terraced house, and up to 50m³ on a semi-detached or detached house. Any previous roof enlargement counts against that figure, even one a previous owner built. The new volume must also sit no higher than the existing ridge.

For rear extensions, the limit is depth. Single-storey rear extensions are generally allowed to 3m on a terraced or semi-detached house and 4m on a detached house, within height limits. The prior approval route for larger home extensions can double those depths, subject to a neighbour consultation.

One difference matters more than the rest. Permitted Development rights for roof enlargement are removed on designated land, which covers conservation areas, National Parks, Areas of Outstanding Natural Beauty and World Heritage Sites. South London has plenty of designated streets, and an Article 4 direction can strip rights further.

This is general guidance and your property may differ. Confirm your own position with your borough’s planning department, and consider a Certificate of Lawfulness if you’re relying on Permitted Development.

A third storey triggers fire rules, and that’s the biggest hidden cost

If your loft creates a third storey, Part B of the Building Regulations changes what the whole house has to do. This is the line item that most often separates a £30,000 quote from a £55,000 one.

You’ll need a protected stairway: a continuous escape route from the loft down to a final exit, enclosed in construction that resists fire for 30 minutes. In practice that means fire doors to the habitable rooms opening onto the stair, and upgraded doors on the floors below. The new floor between storeys has to resist fire for 30 minutes too. Mains-wired, interlinked smoke alarms go in on every level.

None of it is visible in the finished room, and all of it is chargeable. Where a protected stairway can’t be achieved, a sprinkler system or an alternative escape arrangement may be needed, agreed with building control case by case.

A single-storey extension avoids this entirely. Its regulatory weight sits in structure, foundations and insulation instead.

Guidance here is general, and building control applies it to your specific layout. Get their view early, not after the drawings are fixed.

Both routes can put you under the Party Wall Act

Neither option escapes the Party Wall etc. Act 1996, so don’t treat it as an extension-only problem.

A loft conversion usually engages it under Section 2, because new floor or roof beams bear into the shared wall. A hip-to-gable, which replaces the sloping side of the roof with a vertical wall, often raises or cuts into that wall as well.

A rear extension engages Section 6 instead, because you excavate foundations within 3m of a neighbour’s structure. Section 1 also applies where a new wall goes up on the line of junction between the two properties.

Either way you serve notice, and either way an agreed surveyor costs around £1,000. A mid-terrace with neighbours on both sides can need two awards. Speak to a party wall surveyor about your specific boundary before you fix the budget.

Bedroom count drives valuation, but published uplift figures are weak

Here’s the part usually filled with a confident percentage. We’re not going to give you one. The widely repeated “a loft adds x% to your home’s value” claims trace back to agency marketing, not to a published dataset with a stated method. The evidence is weak, so treat the number as weak.

What’s defensible is narrower and more useful. Buyers search and filter by bedroom count, so going from three bedrooms to four changes who sees your listing at all. A loft that adds a genuine double with a shower room does that. A loft that adds one bedroom while shrinking another may not.

An extension works differently. It rarely changes the bedroom count, so it competes on kitchen quality, light and how the ground floor flows. Buyers feel that on a viewing rather than filtering for it.

If a resale figure matters to your decision, ask two local agents what a four-bedroom version of your house sells for on your street. That’s a real local number.

A garage conversion is the least expensive route to a room

Before committing to either, check whether you already own the space. A garage conversion runs £8,500 to £20,000, averaging about £14,250 (HomeOwners Alliance, 2026), and often falls under Permitted Development.

The walls, roof and foundations exist. You’re insulating, infilling the garage door, adding a window, damp-proofing the floor and wiring it. That’s why it lands at roughly a third of a dormer loft.

The trade-off is worth stating plainly. Most garages face the wrong way for light, sit at the front away from the garden, and lose you the storage the family was using. Good home office. Good playroom. Rarely the room that fixes a cramped kitchen.

How to decide, in four questions

Work through these in order. The first one that gives you a clear answer usually settles it.

1. Which room are you short of? Bedrooms and bathrooms point up. Kitchen, dining and sitting space point out. This question alone resolves most cases.
2. What does your garden do for you? If it’s where the children play, protect it and go up. If it’s a strip you mow and ignore, an extension costs you little you value.
3. Does the loft physically work? Measure the head height against the 2.2m rule of thumb, identify whether the roof is cut or trussed, and draw the staircase on the first-floor plan. If any of the three fails, the loft stops being the cheaper-looking option.
4. What does your borough allow? Check for a conservation area, an Article 4 direction and any previous roof enlargement. Designated land removes loft Permitted Development rights outright.

Answer those and the build decision follows. The question of what the space is like to live in still has to be designed.

What to do next

Go and measure the loft, then go and stand in the garden. Those two five-minute checks show you what you’d gain and what you’d give up, which is more than any cost table does.

Then draw the staircase on your first-floor plan, before you draw anything in the loft. If the stair works and the head height is there, you have two live options. If it doesn’t, you have one, and you found out for free.

If you’d like both routes tested against your actual house, Rapid Bee covers South of London, including Bromley, Bexley, Greenwich, Lewisham and Southwark, and will talk through realistic ranges before any drawings exist. For more information, read about our house extensions and loft conversions.

Frequently Asked Questions

Is a loft conversion cheaper than an extension?

Not reliably. A loft runs £27,500 to £75,000, with a dormer averaging about £50,000 (HomeOwners Alliance, 2026). A 20m² London extension is roughly £46,000 to £68,000 of build, at £2,300 to £3,400 per m² from the same source. The ranges overlap, so cost rarely decides it. Both figures are indicative for South London as at September 2026.

What head height do I need for a loft conversion?

About 2.2m of clear height from the top of the ceiling joists to the ridge, as a rule of thumb. It isn’t a regulation, since England sets no statutory minimum ceiling height for loft conversions. Below that, the finished room stops being comfortable once floor and insulation are in.

Do I need planning permission for a loft conversion?

Often not. Permitted Development allows 40m³ of extra roof space on a terraced house and 50m³ on a semi-detached or detached house, within height limits. Those rights are removed on designated land, including conservation areas. This is general guidance, so confirm your position with your borough.

Can I do both? (House Extension & Loft Conversion)

Yes, and sequencing matters. Running a loft and a rear extension as one contract shares scaffolding, one set of fees and one disruption period. Doing the loft first also lets the structural engineer design for it, rather than retrofitting support later.

* All figures on this page are indicative for South London as at September 2026 and are not a quote. Costs move with roof structure, ground conditions, specification and access. Regulatory guidance here is general; your property may differ, so confirm your position with your local authority, building control or a party wall surveyor before committing.

Thinking about an orangery extension? Discuss your house extension with Rapid Bee.

Create More Space With a Premium Orangery Extension

A well-designed orangery can transform the relationship between your home and garden. It can also create a comfortable new room for everyday life, from open-plan cooking and dining to relaxed family time.

• Gain year-round living space – Create a practical kitchen, dining room or family area.
• Bring in more natural light – Combine generous glazing with a carefully positioned roof lantern.
• Create an architectural finish – Match masonry, proportions and details to your existing home.
• Connect your home and garden – Add bi-fold or sliding doors for wide views and easy access.

The right design balances daylight, insulation, structure and style. We consider each element as part of one extension rather than treating the glazing, roof and walls as separate features.

What Is an Orangery Extension and How Works?

An orangery extension is a substantial home extension with a high proportion of glazing. It usually combines masonry walls or pillars, an insulated solid roof, a glazed roof lantern and large windows or doors.

That construction creates an important distinction. A modern orangery should feel like a natural part of your home, rather than a lightweight glazed room attached to it.

A typical orangery extension can include:

• Brick or rendered masonry that complements the existing house.
• Substantial columns or pilasters between glazed sections.
• An insulated perimeter roof with a central roof lantern.
• Full-height windows or structural glazing.
• Bi-fold or sliding doors facing the garden.
• An insulated floor with integrated heating.

This combination gives us considerable design flexibility. We can create a bright garden-facing room while retaining useful solid surfaces for kitchens, lighting, furniture and interior finishes.

Understand the Anatomy of an Orangery Extension

Picture the orangery from the garden. Large glazed doors sit between substantial masonry sections. Above them, an insulated roof surrounds a raised glazed lantern. An insulated floor completes the thermal envelope below.

The proportions matter as much as the individual materials. Good orangery design makes the solid and glazed elements feel deliberate, balanced and appropriate for the original house.

Orangery, Conservatory or Extension: Which Suits You?

Homeowners often compare an orangery with a conservatory or conventional rear extension. All three can increase usable space, but their construction, appearance and relationship with the existing house differ.

An orangery often suits homeowners who want more architectural substance than a traditional conservatory without losing the dramatic daylight and garden views associated with extensive glazing.

A conventional house extension can offer greater freedom for major internal reconfiguration. The best choice depends on your property, priorities, budget and intended use.

How Much Does an Orangery Extension Cost London?

There is no reliable single price for an orangery extension in London. Size matters, but structure, glazing, access, finishes and the amount of work inside the existing house can change the total investment significantly.

Typical London orangery extension budget

Treat online cost ranges as an initial guide rather than a quotation. London pricing varies considerably by size, specification, structural work, glazing and finish. We price projects around the actual property and agreed scope.

The main cost factors include:

1. Footprint and dimensions. A larger room needs more foundations, structure, roofing, glazing and finishing work.
2. Structural alterations. Wide openings through the original rear wall can require substantial structural support.
3. Windows and doors. Frame material, glass specification and opening configuration affect price.
4. Roof lantern. Size, material, glazing and structural requirements influence the overall cost.
5. Architectural detailing. Bespoke masonry, pilasters, cornices and matching finishes add craftsmanship.
6. Heating and electrics. Underfloor heating, lighting circuits and additional power form part of a finished room.
7. Interior fit-out. Kitchens, flooring, decorating and joinery can represent a significant part of the final budget.
8. Site logistics. Restricted access and construction constraints can affect labour and delivery requirements.

Compare quotations on the same basis. A shell price can look attractive beside a completed-room quotation, but the two figures may cover very different scopes. Fees outside the builder’s price, from the structural engineer to building control, are set out in the costs nobody quotes you.

Want a realistic figure for your property? Ask Rapid Bee about your extension and we can discuss the space, specification and finish you have in mind.

Does an Orangery Extension Need Planning Permission London?

An orangery does not receive a special planning category simply because we call it an orangery. Planning requirements depend on the proposed work, the property and the planning constraints that apply to the site.

Some house extensions can fall within permitted development rights. The proposal still needs to meet the relevant limits and conditions. Factors can include:

• The extension’s height and depth.
• Its position in relation to boundaries.
• The amount of land around the original house that development covers.
• Previous additions to the property.
• The property’s location and planning designations.
• Conservation area or other local restrictions.
• Listed status.
• Any Article 4 direction that removes specific permitted development rights.

Flats and maisonettes also need separate consideration. Householder permitted development rights do not apply to them in the same way as they apply to many houses.

Planning permission and Building Regulations also serve different purposes. A project can avoid a full planning application yet still need Building Regulations approval for areas such as structure, insulation, glazing, drainage and electrical work.

South London contains varied streets, property types and planning constraints. We recommend checking the current national rules and the requirements of the relevant local authority before construction starts.

Which Homes Work Best With Orangery Extensions?

An orangery can work with modern and traditional architecture. The strongest designs respond to the proportions and materials of the existing house rather than imposing one standard orangery style on every property.

Detached Homes Give Orangery Designs Greater Freedom

Detached properties can provide scope for wider garden-facing designs and strong symmetry. A generous roof lantern and broad glazed openings can suit the proportions of a larger rear elevation.

The extra flexibility can also support distinct kitchen, dining and seating zones. Careful planning still matters because the new room should remain proportionate to both the house and garden.

Semi-Detached Homes Suit Practical Orangery Living Spaces

A semi-detached home can suit an orangery that enlarges a kitchen or creates a combined dining and family space. The design can bring daylight deeper into the rear of the property.

Boundary relationships need close attention. We also consider the visual mass of the extension, neighbouring amenity and the way the new structure meets the original house.

Period Homes Reward Carefully Detailed Orangery Extensions

Period homes can pair beautifully with orangeries because masonry, vertical proportions and carefully divided glazing can echo traditional architecture without copying it mechanically.

Brick choice, pilaster proportions, cornice details and frame profiles all influence the result. A contemporary lantern and large doors can still work when the wider composition respects the original building.

Terraced Homes Can Also Accommodate Orangery Designs

A terraced house presents a tighter design problem, but that does not rule out an orangery-inspired extension. A roof lantern can bring valuable overhead daylight into a deeper ground-floor plan.

The available width, neighbouring properties, party-wall considerations and garden depth can shape the design. A tailored layout usually works better than a standardised orangery system.

How Should You Design a Modern Orangery Extension?

The best orangery design starts with the room’s purpose. A kitchen needs different solid wall space, lighting and services from a lounge, while a dining room may benefit from a direct visual axis towards the garden.

Three features have a particularly strong effect on the finished space.

Roof Lanterns Bring Daylight Deep Into Extensions

A roof lantern introduces light from above and creates a strong architectural focal point. Its position can help illuminate the centre of a room, including areas that sit away from garden-facing doors.

Bigger does not automatically mean better. We consider scale, orientation, glazing specification and summer solar gain alongside the visual effect.

Bi-Fold Doors Create Wide Garden-Facing Openings

Bi-fold doors can open a large section of the rear elevation and create a strong connection with a terrace or garden. Sliding doors can offer larger individual panes and fewer vertical sightlines.

Frame dimensions, thresholds and opening arrangements deserve early consideration. These details influence views, circulation and the relationship between indoor and outdoor floor levels.

Underfloor Heating Keeps Valuable Walls Clear

Underfloor heating can work particularly well in a highly glazed extension. It distributes heat across the floor and removes the need to reserve prime wall positions for conventional radiators.

Rapid Bee provides underfloor heating alongside wider electrical, plumbing and heating services. An integrated approach helps us plan the room around both appearance and everyday comfort.

Good design also considers ventilation, solar-control glazing, lighting zones, sockets and interior flooring. These practical details turn an impressive structure into an easy room to live in.

Will an Orangery Stay Comfortable Throughout Every Season?

Modern orangery comfort depends on the complete building envelope. A roof lantern alone does not determine performance, and large areas of glass do not automatically make a room uncomfortable.

A strong specification considers:

• High-performance glazing for windows, doors and the lantern.
• Effective insulation within the solid roof sections.
• Floor insulation that limits unwanted heat loss.
• Careful detailing around junctions and structural elements.
• Solar gain from the orientation and quantity of glazing.
• Ventilation for warm days and occupied spaces.
• Suitable heating for colder periods.
• External or internal shading where the design requires it.

These elements need to work together. We approach an orangery as a permanent living space and specify the wider construction around the comfort that the room needs to deliver.

Orangery Design Terms Every Homeowner Should Understand

Orangery quotations and design discussions can contain unfamiliar terminology. Understanding a few core terms makes it easier to compare proposals and make informed choices.

Lantern roof: A raised glazed structure within a predominantly solid roof. It brings natural light into the room from above and often forms the orangery’s main ceiling feature.

Structural glazing: Glass used as an integrated architectural element. Some systems minimise visible framing and create broad, clean glazed areas.

Dwarf wall: A low masonry wall beneath windows or glazing. Traditional conservatories and some orangery designs use dwarf walls around their perimeter.

Pilaster: A vertical architectural element that projects from a wall and resembles a shallow column. Pilasters can give an orangery its substantial, balanced appearance.

Thermal break: An insulating element that reduces heat transfer through a conductive component, such as a metal frame.

Solar gain: Heat that enters a room through sunlight. It can provide useful warmth in cooler periods but needs control during warmer weather.

U-value: A measure of heat transfer through a building element. Lower U-values generally indicate better insulating performance.

These terms describe individual components, but performance comes from the complete design. Ask how the roof, glazing, structure, floor, ventilation and heating work together.

Is an Orangery Extension Right for Your Home?

An orangery sits in a distinctive part of the extension market. It offers more masonry and architectural integration than a typical conservatory while retaining far more overhead and garden-facing glazing than many conventional extensions.

An orangery could suit your plans if you want:

• A bright kitchen, dining or family room for everyday use.
• More structural substance than a traditional conservatory.
• A prominent roof lantern as an architectural feature.
• Generous views and direct access to the garden.
• A design that combines masonry with large areas of glass.
• A premium extension tailored to the character of your house.

A conventional rear extension may make more sense when your priority centres on extensive internal reconfiguration, maximum solid wall space or a different architectural treatment.

The decision should follow the property and your plans for it. We can explore the practical options before you commit to one extension type.

Explore Our South London House Extension Projects

Finished projects give you a better sense of scale, detailing and material combinations than product specifications alone. Our work focuses on creating additional space that feels considered, functional and connected to the original home.

Project gallery content: Feature relevant extension projects from Southwark, Lewisham, Greenwich, Bexley, Bromley and surrounding areas. Each card should show the location, extension type and standout design feature.

Explore Rapid Bee projects and extension services to see how thoughtful design and skilled construction can reshape a home.

Orangery Extension Questions South London Homeowners Ask

You might have some questions after comparing an orangery with other extension types. Below are the most common questions we get asked:

Plan Your Orangery Extension With Rapid Bee

We build house extensions around the people who will use them. Our team can manage the journey from design and planning through construction and finishing, with a focus on quality, clear communication and practical detail.

We work with homeowners across Southwark, Lewisham, Greenwich, Bexley, Bromley and surrounding areas. Tell us what you want to change, and we can explore the extension options that suit your home.

Ready to create a brighter, more spacious home? Discuss your orangery extension with Rapid Bee.

*Planning and cost information in this guide provides general guidance only. Planning rules, permitted development rights, Building Regulations and project prices depend on the property and current requirements. Confirm the relevant rules and obtain a project-specific quotation before proceeding.

This Lewisham property had a ground floor that wasn’t working – a closed-off kitchen, disconnected rooms, and a layout that hadn’t kept pace with the way the family lived. The brief was straightforward: open it up, make it flow, and do it properly. No extension, no extra footprint – just structural work, smart design, and quality throughout.

Initial Situation

The client’s ground floor had a layout common to many Lewisham period properties – a series of closed-off rooms that felt disconnected and underused. The kitchen in particular felt cramped and separate from family life, with little natural light and no flow into the dining or living areas.

The client wanted to open the ground floor up entirely: connecting the kitchen to the dining area, improving the relationship with the living room, and creating a space that worked for the way their family actually lived – all within the existing footprint, without extending the property.

Challenges Faced

• Load-bearing structure: The wall separating the kitchen from the dining area was load-bearing, meaning removal required a structural engineer, precise steel beam installation, and building control sign-off before any finishing work could begin.
• Maintaining connection and privacy: The client wanted the kitchen and living room to feel connected – but not permanently open. Finding the right solution meant balancing openness with the option to separate the spaces when needed.
• Coordinating multiple trades: Structural alterations, electrical reconfiguration, plastering, kitchen installation, flooring, and decoration all needed to be sequenced and delivered without gaps or delays.

Solution and Execution

Design Phase

• Worked with the client to map out the new ground floor layout before any work began, confirming the open-plan configuration and pocket door position.
• Structural engineer engaged to design and specify the steel beam solution for the load-bearing wall removal.
• Pocket door system selected and specified at design stage to ensure the structural opening was formed to the correct dimensions first time.
• Electrical layout, kitchen design, and flooring specification all finalised before work started to avoid changes mid-build.

Construction Phase

• Structural alterations carried out including safe removal of the load-bearing kitchen wall.
• New steel beams installed and signed off by building control.
• Open-plan kitchen and dining space formed across the full ground floor width.
• Kitchen-to-living room opening widened and fitted with a double pocket door system.
• Complete electrical reconfiguration and new installations throughout the ground floor.
• Full skim plastering across all altered areas.
• New kitchen supplied and installed.
• New flooring laid throughout.
• Full painting and decorating completed.

Results and Benefits

The ground floor at South Park Crescent is unrecognisable. What was a series of closed-off, underused rooms is now a bright, open, and highly functional space – built around the way this family lives.

• Open-plan living: The kitchen flows directly into the dining area, with natural light moving freely through the space for the first time.
• Flexible connection: The double pocket door system means the spaces can be fully open or completely separated – far more practical than a fixed opening and far more elegant than a standard door.
• Full finish quality: New kitchen, flooring, and decoration tie the entire ground floor together into a cohesive, considered finish throughout.
• Structural confidence: All load-bearing alterations were engineered, signed off by building control, and carried out by the Rapid Bee team – no subcontractors, no gaps in accountability.

This project is a strong example of what thoughtful structural work and refurbishment can unlock – without a single square metre of new floor space added.

Thinking About Opening Up Your Ground Floor?

From structural alterations to full kitchen installations, Rapid Bee handles everything in-house across Lewisham, South London, and surrounding areas – one team, one point of contact, zero compromise on quality.

Get in touch with Rapid Bee today.

From structural reconfiguration to silicone render, bespoke joinery to wet underfloor heating, every element was designed and built in-house by our team – one point of contact, start to finish.

Initial Situation

The client came to us with an ambitious brief: to completely reimagine their family home from the ground up. The property had real potential but was constrained by an outdated layout, poor energy performance, and a tired exterior that didn’t reflect the quality of life the family wanted inside.

Their vision was clear – more space, better flow, a modern finish throughout, and a home that would work for their family for years to come. The scope covered virtually every element of the property, from the footprint and roof structure down to the flooring and decoration.

Challenges Faced

• Scale and sequencing: Delivering a project of this scope as a single coordinated build required precise sequencing across structural work, groundworks, roofing, render, windows, and a full internal fit-out – all without compromising quality at any stage.
• Structural reconfiguration: The existing property required significant load-bearing alterations to achieve the open layout the client needed, demanding careful engineering and building control sign-off before any cosmetic work could begin.
• Exterior continuity: Applying silicone render across the entire property – including the new loft conversion – required the new and existing structures to be built and finished to the same standard, with no visible joins or inconsistencies.
• Bespoke elements: The handcrafted timber porch required traditional joinery skills to be built and fitted on site, with no off-the-shelf solution available for the client’s chosen design.

Solution and Execution

Design Phase

• Worked closely with the client to finalise the full layout, material specification, and finish choices before any work began.
• Structural alterations and steel positions were engineered and signed off, with building control engaged from the outset.
• The loft conversion was planned in parallel with the re-roofing scope to maximise efficiency and avoid double-handling.
• Silicone render system, uPVC window specifications, and UFH layout were all confirmed at design stage to avoid costly changes mid-build.

Construction Phase

• Full structural reconfiguration of the existing property, including removal and replacement of load-bearing elements.
• Rear extension constructed to expand the ground floor living and kitchen space.
• Loft conversion completed to create a new upper-floor room without reducing garden space.
• New detached outbuilding built to the rear – suitable as a home office, studio, or storage.
• New driveway installed to the front elevation, improving access and kerb appeal.
• Bespoke timber porch handcrafted and fitted on site.
• Silicone render system applied across the entire property including the loft conversion.
• New uPVC windows installed throughout, improving insulation, security, and natural light.
• Wet underfloor heating system installed across the full ground floor.
• Full ground floor tiling laid to a seamless finish throughout.
• Complete internal refurbishment – plastering, electrics, plumbing, and decoration throughout.

Results and Benefits

The transformation at Harland Avenue is, quite simply, a different home. What was a dated, constrained property is now a modern, spacious, and energy-efficient family house – with the kerb appeal to match.

• Expanded living space: The rear extension and loft conversion added meaningful square footage across two floors, giving the family the room they needed without sacrificing the garden.
• Contemporary exterior: Silicone render across the entire property – including the loft – combined with new uPVC windows gives the home a clean, cohesive finish that stands out on the street.
• Modern comfort: Wet underfloor heating across the ground floor replaced traditional radiators, delivering even, efficient heat throughout the new open-plan layout.
• Flexible additional space: The detached outbuilding gives the family genuine flexibility – whether used as a home office, play space, or storage.
• Quality throughout: Every element – from the handcrafted porch to the last tile on the ground floor – was completed by the Rapid Bee team to the same standard.

The client moved back into a home that finally matched their ambitions for it – and one that will serve their family for decades to come.

Thinking About Transforming Your Home?

Whether you’re planning a full house transformation, an extension, or a loft conversion in Sidcup, South London, or the surrounding areas – Rapid Bee delivers quality you can see and value you’ll feel for years.

Book your free consultation with Rapid Bee.

This guide walks you through the real-world decisions homeowners face – the practical ones, the design ones, and the “will this actually feel right to live in?” ones. And to make things easier, we’ll describe each extension type in plain, visual terms so you can picture how it fits with your own home.

Start by Looking at the Home You Already Have

Before you fall in love with glossy images on Pinterest, take a step back and look at your home’s shape, layout, and limits. The best extension isn’t the biggest – it’s the one that fits your property and your lifestyle.

Key things homeowners usually need to think about:

1. How your home is shaped

A detached home gives you freedom on all sides. A semi-detached gives you one open side. A terrace often only allows you to build at the rear or into the side passage.
Your existing form determines what’s realistic – and what’s not worth the fight with planning.

2. How much garden do you want to keep

More extension means less garden. Most homeowners want both.
The best design strikes a balance for daily life, not just square metres.

3. How natural light currently enters your home

Extensions that block key windows can create darker, tunnel-like spaces if they’re not planned well. Understanding where the sun hits your home helps you avoid that.

4. Access for construction

If everything has to go through the house, the job takes longer and costs more. Not a dealbreaker – but worth knowing upfront.

5. Your long-term plans

Are you staying for decades? Thinking of selling in a few years?
Different extension types add different types of value.

Once you understand your home’s starting point, choosing the right extension becomes far simpler.

Single-Storey Rear Extension

A rear extension pushes your home into the garden to create a brighter, more generous ground-floor space.

If your kitchen feels cramped or your living space doesn’t connect well to the garden, this is usually the go-to solution. Picture your back wall moved further out and replaced with wide doors, rooflights, and an open, airy space that changes the flow of your home.

Why homeowners choose this option

• You want a bigger kitchen or kitchen-diner
• You want an open-plan living area
• You want to improve access to the garden
• You want more natural light

Considerations to keep in mind

• The deeper you go, the more you lose from the garden.
• Large openings usually need structural support, which affects cost.
• Good glazing and thoughtful lighting make the space feel uplifting, not cave-like.
• Flat roofs, lanterns, or pitched roofs all create different moods.

Common challenge for homeowners

Rear extensions are simple in concept – but the layout decisions inside are where homes are made or broken. A great rear extension fixes the flow of your home, not just enlarges it.

Single-Storey Rear Extension Cost

A single-storey rear extension in London costs £2,300 to £3,400 per m² to build (HomeOwners Alliance, 2026), with £3,000 to £6,000 of fees on top.

Cost mostly depends on the functionality of the space – things like kitchen appliances, ventilation, heating, glazing, and how much structural work is needed. At those rates a 20m² rear extension is roughly £46,000 to £68,000 of build, before fees and before a new kitchen, which is a separate line of about £20,000 (Architecture for London, 2026).

Side-Return (Side-Infill) Extension

A side-return extension fills in the narrow alley beside many period homes, turning “bin space” into valuable living space.

If you have a Victorian or Edwardian terrace or semi, you probably have a thin strip of land down the side that serves no real purpose. Building over it can widen your kitchen and make the whole ground floor feel less cramped.

Why homeowners choose this option

• Your kitchen feels long and narrow
• You want to widen the ground floor without losing garden depth
• You want more light in the centre of the home
• You want a practical extension that feels “natural” to the house

Considerations to keep in mind

• Blocking existing side windows means you’ll rely heavily on rooflights.
• The area is narrow, so construction can be slower.
• It’s a clever way to add floor area without pushing too far into the garden.

Common challenge for homeowners

Light. If the design doesn’t bring enough light from above, the widened space can feel dull. Rooflights become your best friend here.

Side-Return Extension Cost

A side-return extension is built at the same London single-storey rate of £2,300 to £3,400 per m² (HomeOwners Alliance, 2026), and usually sits in the upper half, because the space is tight, access is limited, and roof glazing is usually essential.

Costs rise with high-end rooflights, drainage relocation and premium finishes. Diverting a drain alone runs £1,500 to £5,000 (StructuralEngineerCalcs, 2026), and Victorian terraces often have one under the side return.

Wraparound Extension

A wraparound extension combines a rear extension and a side-return extension into an L-shaped design that transforms the entire ground floor.

If you’re dreaming of a spacious kitchen-dining-living hub – the kind that feels like the heart of the home – this is the big-impact option.

Why homeowners choose this option

• You want a full, open-plan family space
• You want zones for cooking, dining, relaxing and working
• You want to reshape the layout completely
• You want to maximise the ground-floor footprint

Considerations to keep in mind

• These extensions are deep – so lighting design is essential.
• They often require more steelwork and structural changes.
• They rarely fall under permitted development, so planning is usually needed.
• They can dramatically lift the lifestyle and value of your home when done well.

Common challenge for homeowners

Too much open space with no zoning can feel noisy or unfocused. The best wraparound extensions create clear “moments” within the space.

Wraparound Extension Cost

A wraparound extension is priced on the same London single-storey rate of £2,300 to £3,400 per m² (HomeOwners Alliance, 2026), usually toward the top, as it combines both rear and side works and involves major structural openings.

Functionality (like a full kitchen), larger steel spans, and high-performance glazing affect the final cost. The structural engineer alone runs £1,200 to £1,500 on a wraparound, against £550 to £900 for a straightforward rear extension (StructuralEngineerCalcs, 2026).

Though wraparound extensions are usually way more spacious than 20m², but you get the idea.

Double-Storey Extension

A double-storey extension builds outwards on the ground floor and adds new space above at the same time.

If your home lacks bedrooms or bathrooms – and the ground floor needs work too – this offers the strongest value for money.

Why homeowners choose this option

• You want more sleeping space
• You want an en-suite or extra bathroom
• You want a bigger kitchen or living area downstairs
• You want to improve natural light and circulation across the home

Considerations to keep in mind

• The upstairs layout needs to align with your existing landing and bedroom flow.
• Privacy and overlooking matter more at upper level.
• The design should feel like a natural part of the house, not an add-on.

Common challenge for homeowners

Thinking about the home as a whole – not two separate floors. The best designs improve both levels in one coordinated move.

Double-Storey Extension Cost

A double-storey extension costs around £1,900 per m² (HomeOwners Alliance, 2026), less per square metre than a single-storey one, because the foundations and roof are shared across two floors.

The cost depends on whether the upper level includes a bathroom, the type of finishes, and how the new spaces integrate with existing rooms. It still costs more in total than a single-storey build, and it is far more likely to need full planning permission.

Loft Conversion

A loft conversion turns unused attic space into a bedroom, office or studio without altering your garden.

If your loft has enough height, this can be one of the most cost-effective ways to add a whole new room.

Why homeowners choose this option

• You want a peaceful, elevated bedroom
• You want a home office away from ground-floor noise
• You want to add value without touching the garden
• You want to make the most of every inch of the home

Considerations to keep in mind

• Head height is the first thing to check.
• Dormers offer more usable space than rooflights alone.
• Stairs need thoughtful placement so the loft feels part of the home.

Common challenge for homeowners

Lofts can feel dark or low if the wrong windows or dormer shapes are used. The right glazing placement makes all the difference.

Loft Conversion Cost

A loft conversion costs £27,500 to £75,000, with a dormer averaging about £50,000 (HomeOwners Alliance, 2026), depending on insulation requirements, staircase design, glazing and the presence of a bathroom.

The top of that range is a fully fitted dormer suite with an en-suite bathroom, roof windows and bespoke joinery.

Garage Conversion & Over-Garage Extension

Garage Conversion

A garage conversion turns an unused or underused garage into warm, practical living space.
It’s one of the quickest ways to gain a new room without changing your footprint.

Great for: playrooms, offices, guest rooms, utility rooms.

Over-Garage Extension

If your garage structure allows it, you can build a new room directly on top – often a bedroom or study.

Considerations for homeowners

• The existing garage may need strengthening
• Parking availability matters for planning
• The new room should connect logically to your upper floor

Common challenge

Ensuring the new space feels properly insulated and soundproofed – not like a converted bolt-on.

Garage Conversion/Extension Cost

A garage conversion costs £8,500 to £20,000, averaging about £14,250 (HomeOwners Alliance, 2026), as the shell already exists and you’re mainly paying for insulation, flooring, internal walls and utilities.

A minimal conversion sits at the bottom of that range, while a fully fitted room with heating, an upgraded façade and high-spec finishes sits at the top.

Over-Garage Extension Cost

Building above a garage is priced much like other two-storey work, but only if the existing foundations are strong enough.

If reinforcement is required, costs rise quickly. Have a structural engineer check the foundations before you set a budget.

Basement Extension

A basement extension digs below the house or garden to create an entirely new level of space.

This is a premium option used when above-ground space is limited.

Why homeowners choose this option

• You want a media room, gym, guest suite or playroom
• You have a compact plot in a high-value area
• You want major space without altering the look of the house

Considerations to keep in mind

• Basements are the most technical and disruptive extension type
• Excavation, waterproofing and engineering are significant
• Light wells and ventilation determine how it feels to live in

Common challenge

Balancing the cost with the lifestyle benefits. In the right homes and locations, the investment makes strong sense.

Over-Garage Extension Cost

A basement extension is the most expensive option per square metre, mainly due to excavation, waterproofing, and structural work.

Light wells, underfloor heating, ventilation systems and high-end finishes all add to that, so price a basement against a survey of your own house rather than a published average.

Orangery vs Conservatory

Orangery

An orangery has solid walls, a lantern roof and large windows – it feels like a proper room that works all year round. Many homeowners use it as a dining room or second living room.

Conservatory

A conservatory is lighter and more glass-heavy. It’s bright and uplifting, but it can run hot in summer and cool in winter unless specified well.

Homeowner considerations

• How often you want to use the space
• Whether you want it to feel like part of the main home
• Orientation and heat control
• Furniture layout and privacy

Orangery Extension Cost

The cost of an orangery is largely driven by glazing quality, lantern roof design, and integration with the existing house.

A high-performing, year-round space with premium doors and lighting costs considerably more than a basic one, so compare quotes on the same specification.

Conservatory Extension Cost

A conservatory usually costs less than an orangery, depending on frame quality, glass performance and heating.

A fully insulated, high-spec version that feels more like a permanent room costs considerably more than a minimal one.

Kitchen Extensions: A Category All Their Own

Most extensions revolve around the kitchen. It’s where families spend most of their time.

If you’re thinking kitchen-first

• Focus on natural light
• Plan storage early
• Decide how cooking, dining and relaxing will flow together
• Think about views – both inside and outside
• Keep circulation clear so the room feels calm, not chaotic

The right kitchen extension changes the way you live every single day.

What Homeowners Often Find Challenging

Choosing an extension type isn’t about picking from a menu – it’s about choosing the upgrade that truly improves how you live.

Homeowners typically struggle with:

• Light: Will the new space feel bright or boxed-in?
• Flow: How will rooms connect and move together?
• Garden: How much outdoor space are you comfortable trading for indoor comfort?
• Planning: What will your council allow?
• Budget: Where should you invest, and where can you save?
• Value: Which extension adds long-term appeal?

The right extension feels natural – as if the home should always have been this way.

Conclusion: Choosing the Right Extension for Your Life

Your extension is more than extra metres – it’s a chance to reshape your home around the way you live.
When you understand your property, your lifestyle, and the role each extension type plays, the decision becomes clear:

• Rear extensions open the home to the garden
• Side returns widen tight layouts
• Wraparounds create full family spaces
• Double-storey builds balance living and sleeping
• Lofts add calm, elevated rooms
• Garage conversions unlock underused space
• Basements create whole new worlds underground
• Orangeries and conservatories add light-filled charm

When you choose the extension that fits your life, the transformation feels effortless every day that follows.

Ready to explore your extension options?

If your home feels like it’s almost perfect – just missing that extra space or better flow – let’s talk. We’ll help you understand what will work, what won’t, and what will make the biggest difference to your everyday comfort.

Book Your Free Consultation