Area guide · N9 & N18
House Extensions in Edmonton (N9 & N18)
Planning a house extension in Edmonton? We design, gain planning permission and build extensions and loft conversions across Lower Edmonton, Upper Edmonton and the streets around Edmonton Green. Most single-storey rear extensions here cost £40,000–£80,000 to build — comfortably under the North London average — applications go through Enfield Council, and its recent decisions here include prior-approval rear extensions, the route that can take a terrace or semi out to 6m. Get us round for a free site visit and we'll spell out what your street supports.
Planning in Edmonton
What Enfield Council has approved in Edmonton
The decisions below come from Enfield's Edmonton Green, Lower Edmonton, Upper Edmonton, Haselbury and Jubilee wards, newest first, across N9 and N18; Jubilee also takes in a few EN1 and EN3 postcodes.
Edmonton's decisions follow its terraces. The loft that keeps coming up is a rear dormer over the main roof with a second dormer over the back addition — the rear outrigger dormer in Enfield's descriptions — usually confirmed through a lawful development certificate, sometimes with a single-storey side infill alongside.
Single-storey rears are just as common, and many go through the prior-approval route. The larger home extension scheme allows a rear extension of up to 6m on a terrace or semi (8m on a detached house) through a light-touch neighbour-consultation process rather than a full planning application. If that's the shape of your project, it's the route to look at first, and we design to it.
Recent planning decisions around Edmonton
Extension, loft and basement applications decided in Enfield's Edmonton Green, Lower Edmonton, Upper Edmonton, Haselbury and Jubilee wards, 23 Sep 2025 to 22 Sep 2026.
The newest decisions in those wards
- ApprovedSep 2026
Lancaster Road, N18
Single storey side infill extension.
26/03277/CEA · Enfield CouncilLawful development certificate
- ApprovedSep 2026
Lancaster Road, N18
Two single storey side extensions.
26/03278/CEA · Enfield CouncilLawful development certificate
- ApprovedSep 2026
Lancaster Road, N18
Single storey rear extension, rear dormer, dormer to rear outrigger and front roof lights.
26/03279/CEA · Enfield CouncilLawful development certificate
- ApprovedSep 2026
Cornwallis Road, N9
Single-storey infill extension, rear dormer with outrigger dormer and front roof lights involving removal of chimney stacks.
26/03269/CEA · Enfield CouncilLawful development certificate
- RefusedSep 2026
Fairfield Road, N18
Rear dormer with rear outrigger dormer, front roof lights and additional windows at side to outrigger dormer.
26/02736/HOU · Enfield CouncilLawful development certificate
- ApprovedSep 2026
Giffard Road, N18
Extension of roof at side to form gable and rear dormer.
26/03271/CEA · Enfield CouncilLawful development certificate
- ApprovedSep 2026
Nightingale Road, N9
Single storey rear extension 6m deep x 3m high (2.8m high to eaves).
26/03281/PRH · Enfield CouncilPrior approval, larger home extension
- ApprovedSep 2026
Cavendish Road, N18
Single storey rear extension 6m deep x 3m high (3m high to eaves).
26/03332/PRH · Enfield CouncilPrior approval, larger home extension
Look a reference up on the council’s own register: Enfield Council planning search.
Source: GLA Planning London Datahub, 23 Sep 2025 – 22 Sep 2026. Data updated September 2026. This list last changed 23 September 2026. The datahub can lag a council’s own register by a few weeks.
These are council decisions on applications in these wards, shown as local planning context. They are not necessarily projects undertaken by us, and they are not our approval rate. Planning outcomes depend on your specific property and proposal.
Local knowledge
Edmonton's housing stock — and what works on each
Edmonton's build costs sit below the North London baseline, and the space they buy is just as useful. Three broad markets, one common thread: family houses that gain a great deal from an extra bedroom or a bigger kitchen.
The Victorian terraces of Lower Edmonton (N9). Classic two-storey terraces with rear additions and side alleys. The strongest moves are the side-return extension (£30,000–£55,000), turning a narrow galley kitchen into a full-width kitchen-diner, and the prior-approval 6m rear extension, a route in regular use across N9. Party wall agreements with both neighbours are usually needed; we manage that as part of the job.
The interwar belt (Upper Edmonton, N18 and the Great Cambridge Road corridor). Bay-fronted 1930s semis and terraces with hipped roofs and proper gardens. Here the hip-to-gable loft conversion with rear dormer (£48,000–£80,000) adds a double bedroom and en-suite without touching the garden, and pairs beautifully with a single-storey rear extension below — plenty of owners phase the two.
Post-war and ex-local-authority family homes. Solidly built, often with wider plots and garages — which makes the garage conversion (£16,000–£30,000) the cheapest extra room in Edmonton, and keeps the rear garden free for a kitchen extension later.
The value-add story. Build costs in Edmonton run 10–15% below the North London baseline, yet a well-designed kitchen extension or loft transforms exactly the kind of three-bed family house this area is full of. If you're weighing "move vs improve" in N9 or N18, those lower build costs tilt the sums towards improving.
Every street is different. That's the point.
We design to Edmonton's stock and to what the council demonstrably approves — not to a template. A free site visit tells you what your house can take.
Get my free estimateHonest numbers
What a house extension costs in Edmonton in 2026
These are realistic all-in build ranges for Edmonton — labour and materials to a good standard, excluding VAT, professional fees and kitchen fit-out:
| Extension type | Typical Edmonton cost | On-site time | Usual planning route |
|---|---|---|---|
| Side-return extension | £30,000 – £55,000 | 2–3 months | Often permitted development |
| Single-storey rear | £40,000 – £80,000 | 3–4 months | Often permitted development |
| Kitchen extension (incl. mid-range kitchen) | £48,000 – £95,000 | 3–4 months | Often permitted development |
| Hip-to-gable loft + rear dormer | £48,000 – £80,000 | 6–10 weeks | Usually permitted development |
| Wrap-around extension | £60,000 – £120,000 | 4–6 months | Full application |
| Double-storey rear | £65,000 – £140,000 | 5–7 months | Full application |
| Garage conversion | £16,000 – £30,000 | 4–6 weeks | Usually permitted development |
As a rule of thumb, Edmonton build costs run £2,400–£3,700 per square metre — 10–15% below the wider North London rate of £2,800–£4,200/m², helped by straightforward stock and plots that are easier to work on. To put that in project terms, a 20m² rear extension works out at £50,000–£70,000 of build cost. The quote you receive after the free site visit is fixed and itemised throughout — the price stays put from contract to completion.
Permissions, handled
Planning permission in Edmonton — what you need to know
Most Edmonton extensions don't need a full planning application. Out of the box, permitted development hands semis and terraces 3m of single-storey rear depth and detached houses 4m — then the larger home scheme, via prior approval, takes those to 6m and 8m. Loft conversions enjoy a generous volume allowance, so most hip-to-gable and dormer schemes proceed without a full application too.
Where you do need permission: double-storey rear extensions, wrap-arounds, anything on flats and maisonettes, and houses where previous owners have already used up permitted development rights — common on terraces extended in decades past. Expect a standard householder application to spend roughly eight weeks with Enfield Council before a decision; prior-approval determinations are typically quicker.
Party walls: almost all of N9 and N18 is terraced or semi-detached, so the Party Wall Act applies to the great majority of projects — budget £1,000–£2,500 per affected neighbour if surveyors are appointed, and start the conversation early. We prepare the notices as part of the job.
Conservation: permitted development rights are restricted in conservation areas, so we check your address against the council's conservation map before any design work starts — no surprises halfway through. Enfield's conservation areas in Edmonton are Church Street, the three Fore Street areas (North, South and Angel), The Crescent and Montagu Cemeteries, and The Crescent carries an Article 4 direction as well. Our North London borough guide covers Enfield's rules alongside Barnet's and Haringey's.
Our approach: we design to what Enfield Council demonstrably approves — and in Edmonton that means making maximum use of the prior-approval route. Where a Lawful Development Certificate is the smarter way to lock in your position, we'll say so and sort it — leaving you with paperwork no buyer's conveyancer can pick holes in.
How it works
How it works
- Free site visit — we tour your Edmonton terrace or semi, hear your plans, and level with you about feasibility, cost and the planning route.
- Design & drawings — working drawings and 3D visuals built around the house you own and the space you need from it.
- Planning, handled — application prepared, lodged with Enfield Council and managed by us until the decision lands.
- Fixed-price build — our vetted North London team carries out the work, gets building control's sign-off and leaves the site spotless.
Our work
Recent work near Edmonton
Edmonton owners can see the build team's full house transformation in Hadley Wood, which took a family home from 120m² to 360m², in the Hadley Wood case study. Bring your own plans up when we visit and we'll go through them with you.
Questions, answered
Edmonton extension FAQs
How much does a house extension cost in Edmonton?
Less than the North London baseline: roughly £40,000–£80,000 for a single-storey rear extension, £48,000–£80,000 for a hip-to-gable loft and £16,000–£30,000 for a garage conversion, excluding VAT and fees. Edmonton build rates run £2,400–£3,700/m² — 10–15% under the North London average.
Is an extension actually worth it on an Edmonton terrace?
Often, yes. Build costs sit below the North London baseline, so each square metre of new kitchen or bedroom costs less to add in N9 and N18. We'll talk honest numbers for your street at the site visit.
What's the prior-approval route, and does it work in N9 and N18?
The larger home extension scheme: a neighbour-consultation process that lets terraces and semis extend up to 6m to the rear (8m for detached homes) without a full planning application. It turns up regularly among the Edmonton decisions on this page.
Do I need full planning permission for my Edmonton extension?
Often not. Standard rear extensions and most lofts proceed under permitted development or prior approval. You'll need a full application for double-storey schemes, wrap-arounds and any work to flats or maisonettes — and if your address falls in a conservation area, permitted development rights are restricted, so we check the council's map first.
How long will Enfield Council take to decide?
Around eight weeks for a standard householder application once validated; prior-approval and lawful development certificate routes are usually quicker. Design and drawings before submission typically take 4–8 weeks, so allow three to four months from first sketch to a green light.
My neighbours are attached on both sides — what about party walls?
Standard for Edmonton terraces: you'll serve notice on both neighbours, and if surveyors are appointed, budget £1,000–£2,500 per neighbour. Most agreements are amicable when the conversation starts early — we prepare all the notices for you as part of the job.
What we build in Edmonton
The same team designs, gets planning and builds — one fixed, itemised price whichever route your Edmonton project takes.
Nearby areas we cover
What clients say
Rated 5.0 on Google
“The Extension Company built a 5m single storey rear extension on our Victorian terrace in Crouch End. Went down the permitted development route so no planning application needed, which they explained up front and saved us months. Kitchen-diner now opens onto the garden with sliding doors. £87k all in, matched the quote.”
“From the initial site visit onwards to my property in Barnet, we felt that the team actually listened to what we wanted. They suggested a few changes to the layout that we hadn't considered, and those changes have made a huge difference. Would definitely use again and recommend”
“Used The Extension Company for a loft conversion on our semi detached in Barnet and couldn't be happier. They explained what was possible at the first visit, sorted the planning side, and gave a fixed price with no surprises at the end. The hip-to-gable and rear dormer gave us a big double bedroom with an en-suite. Tidy, professional and finished on schedule. Would recommend to anyone in North London thinking about a loft conversion.”
“We had been putting off our loft conversion for years because the whole process felt overwhelming. The team made it much easier than expected and handled the drawings, planning and build for us. We now have a lovely extra bedroom and shower room.”
“Our wrap-around extension has completely transformed the ground floor. We now have the open plan kitchen and family space we wanted without losing all of the garden. Thanks to everyone involved.”
“Really pleased with the work from The Extension Company. We had our extension done in Hampstead and the whole experience was excellent. Great communication from start to finish, The quality of the finish is excellent and we’re really happy with the result. Would definitely recommend them if you’re thinking about an extension.”
Reviews shown word for word from our Google profile. See 9 more client reviews · Read all 16 reviews on Google
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