Area guide · HA8
House Extensions in Edgware (HA8)
Planning a house extension in Edgware? We design, gain planning permission and build across HA8 — and we know which council you're dealing with, because Edgware has two: Barnet east of the High Street, Harrow to the west. A single-storey rear extension builds here for £45,000–£90,000, and the hip-to-gable loft with rear dormer is the natural move for Edgware's wall-to-wall 1930s semis. One free site visit and you'll have a clear, honest read on what your street allows.
Planning in Edgware
What Barnet Council has approved in Edgware
Everything in the decision list on this page comes from the Barnet side of the High Street: Barnet's Edgware and Edgwarebury wards, approvals and refusals alike. Harrow's decisions are not in it. If your house is west of the High Street, the relevant record is Harrow's own planning register, and Barnet's list is useful only as a picture of what the same kind of house gets through a few hundred metres away.
Each decision is labelled with its route, and on the Barnet side the prior approvals deserve a second look. Under the larger home extension scheme the council writes to the adjoining neighbours, and its judgement is confined to their amenity, which it only has to weigh if one of them objects. The other way to fail is a scheme that breaks one of the size limits. So a 6m single-storey rear refused on that route has fallen on light, outlook or bulk next door, or on a measurement over the line, and the answer is often a change of depth, height or roof form rather than a different scheme altogether.
Recent planning decisions around Edgware
Extension, loft and basement applications decided in Barnet's Edgware and Edgwarebury wards, 23 Sep 2025 to 22 Sep 2026.
The newest decisions in those wards
- RefusedSep 2026
Highview Gardens, HA8
Roof extension involving partial hip to gable, rear dormer window and 4no. front facing rooflights
26/2669/192 · Barnet CouncilLawful development certificate
- RefusedSep 2026
Aldridge Avenue, HA8
Single storey rear extension with a depth of 6.00m, maximum height of 3.00m and an eaves height of 3.00m
26/2863/PNH · Barnet CouncilPrior approval, larger home extension
- ApprovedSep 2026
Deans Lane, HA8
Roof extension involving hip to gable, rear dormer window, 3no. front facing rooflights and new side gable window
26/3031/192 · Barnet CouncilLawful development certificate
- RefusedSep 2026
Highview Gardens, HA8
Single storey front, side and rear extensions following demolition of the existing garage. Extension of the existing raised terrace area…
26/2651/HSE · Barnet CouncilHouseholder application
- ApprovedSep 2026
Highview Avenue, HA8
Single storey front/side extension to include porch with new front door. Part single, part two storey side and rear extension with 3no…
26/2841/HSE · Barnet CouncilHouseholder application
- ApprovedAug 2026
Glengall Road, HA8
2no. single storey rear extensions with a proposed depth of 6.00 metres, maximum height of 2.80 metres and eaves height of 2.80 metres…
26/2818/PNH · Barnet CouncilPrior approval, larger home extension
- ApprovedAug 2026
Harcourt Avenue, HA8
Single storey rear extension with a proposed depth of 6.00 metres, maximum height of 3.00 metres and eaves height of 2.82 metres…
26/2665/PNH · Barnet CouncilPrior approval, larger home extension
- RefusedAug 2026
Selvage Lane, NW7
Single storey rear infill extension
26/2927/192 · Barnet CouncilLawful development certificate
Look a reference up on the council’s own register: Barnet 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
Edgware's housing stock — and what works on each
The 1930s semi streets. Edgware is Metroland at full strength: street after street of hipped-roof, bay-fronted semis built when the Underground arrived, with side passages and the generous gardens interwar builders allowed. The playbook writes itself. A hip-to-gable loft with rear dormer (£55,000–£90,000) converts the dead hip into a double bedroom and en-suite; our Edgware loft conversion guide goes through the roof options on its own. A single-storey rear extension (£45,000–£90,000) — 3m under standard permitted development, up to 6m with larger-home prior approval — turns the back of the house into one big kitchen-diner. Do both and a three-bed semi becomes a five-bed family home. And because HA8 build costs sit at the standard North London baseline while the space gained is worth real money, the value-add case in Edgware is strong.
West of the High Street — the Harrow side. Cross the High Street and the houses barely change, but the council does: the western side of Edgware, running towards Canons Park, falls under Harrow Council rather than Barnet. National permitted development rules are identical on both sides; what changes is the local process, the policies quoted in decisions and the forms. The Canons Park Estate conservation area is on this side too, and inside it the national shortcuts narrow. Our Stanmore guide covers more of Harrow's patch.
Flats and maisonettes around the centre. Around the station and the town centre, a fair slice of HA8 lives in flats and maisonettes — where permitted development doesn't apply at all. Extensions and loft schemes need full planning plus the freeholder's agreement; we confirm the position before designing.
Every street is different. That's the point.
We design to Edgware'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 estimateOne postcode, three councils
The High Street is the A5, the old Roman Watling Street, and in Edgware it is also the borough boundary: houses on its east side are Barnet's, houses on its west side Harrow's. HA8 does not stop at those two. It reaches into Brent's Queensbury ward as well, so a Brent-decided house can carry an Edgware address.
On the Barnet side, the Edgware and Edgwarebury wards are what our list covers, and Edgwarebury runs east far enough to take in some NW7 streets. The HA8 streets towards Burnt Oak belong to a different Barnet ward, which is where the Watling Estate conservation area sits; the interwar cottage estate is a designated area in its own right, so the standard permitted development rules there are narrower than on the semi streets around it.
None of this changes what can physically be built. It changes the desk your drawings land on, the local plan they are judged against and the register where the decision appears, which is why we confirm the council against the boundary map before any design work starts.
Honest numbers
What a house extension costs in Edgware in 2026
For Edgware, sensible all-in build budgets run as follows — good-quality labour and materials, with VAT, professional fees and kitchen fit-out charged separately:
| Extension type | Typical Edgware cost | On-site time | Usual planning route |
|---|---|---|---|
| Side-return extension | £35,000 – £65,000 | 2–3 months | Often permitted development |
| Single-storey rear | £45,000 – £90,000 | 3–4 months | Often permitted development |
| Kitchen extension (incl. mid-range kitchen) | £55,000 – £110,000 | 3–4 months | Often permitted development |
| Hip-to-gable loft + rear dormer | £55,000 – £90,000 | 6–10 weeks | Usually permitted development |
| Wrap-around extension | £70,000 – £140,000 | 4–6 months | Full application |
| Double-storey rear | £75,000 – £160,000 | 5–7 months | Full application |
| Garage conversion | £18,000 – £35,000 | 4–6 weeks | Usually permitted development |
Edgware sits on standard North London rates of £2,800–£4,200 per square metre — and that's the quiet advantage here: baseline build costs in a well-connected suburb, which is why extensions in HA8 so often cost less than the value of the space they create. Take a 24m² rear scheme: somewhere between £67,000 and £101,000 of build cost at those rates. The price we give you after a free site visit is fixed and itemised, with no padding and no surprises.
Permissions, handled
Planning permission in Edgware — Barnet or Harrow?
The first question on any Edgware project: which side of the High Street are you on? East and you're in Barnet; west, towards Canons Park, and you're in Harrow. The answer changes where we apply, not what's physically possible — permitted development rules are national.
Most Edgware extensions don't need a full application. Your automatic allowance is 3m of single-storey rear depth on a semi or terrace and 4m on a detached house; go through prior approval under the larger home extension scheme and those figures become 6m and 8m. Loft conversions enjoy a generous volume allowance, which is why a hip-to-gable on an HA8 semi can so often go through as lawful development. Whichever authority you fall under, a standard householder application should be decided within roughly eight weeks.
You will need permission for: double-storey and wrap-around schemes, flats and maisonettes, most work in a conservation area — where permitted development rights are restricted — and houses where earlier owners have already used up the PD allowance.
Party walls: Edgware's semis mean the Party Wall Act applies to almost every project — budget £1,000–£2,500 per affected neighbour if surveyors are appointed. We serve the notices as part of the job.
Our approach: we design to what the decision data shows passing, and when lawful development is the cleverer route we'll get the certificate sorted — solid paperwork that future buyers' solicitors will thank you for. If you are weighing Edgware against other parts of Barnet or Enfield, our North London extensions guide compares the councils side by side.
How it works
How it works
- Free site visit — we visit your HA8 home, settle the Barnet-or-Harrow question on the spot, and give plain-spoken advice on feasibility, cost and route.
- Design & drawings — considered plans and 3D visuals that work with your semi's proportions and the way you live in it.
- Planning, handled — we assemble and submit the full application to Barnet or Harrow — whichever side of the High Street you're on — and drive it to a decision.
- Fixed-price build — our trusted North London builders see it through, with building control sign-off and a clean handover at the end.
Our work
Recent work near Edgware
A North London highlight from our build team lately: a full house transformation in Hadley Wood, taking a family home from 120m² to 360m², shown in our Hadley Wood case study. Flag what you're planning for your Edgware semi at the site visit and we'll talk it through.
Questions, answered
Edgware extension FAQs
How much is a house extension in Edgware?
£45,000–£90,000 for a single-storey rear, £55,000–£90,000 for a hip-to-gable loft and £18,000–£35,000 for a garage conversion — excluding VAT and fees, at North London baseline rates of £2,800–£4,200 per square metre. HA8 doesn't carry the premium that Hampstead or Golders Green does, which is exactly why the value-add stacks up.
Barnet or Harrow — who decides my application?
It depends which side of Edgware High Street you're on: east is Barnet and west, towards Canons Park, is Harrow. A corner of HA8 also falls to Brent. We confirm it against the council boundary at the site visit and submit to the right authority — permitted development rules are the same on every side.
Is one council tougher than the other?
The national permitted development framework is identical either side, so straightforward rears and lofts follow the same rules wherever you are in HA8. Local policies and process differ in the details, so we frame each HA8 application for the council that will decide it.
Why don't I see Harrow decisions on this page?
The decisions shown are Barnet's alone, from its Edgware and Edgwarebury wards. For a house west of the High Street, look on Harrow's own planning register; we check both before we design, so a Harrow-side scheme is drawn to Harrow's policies.
What suits a 1930s Edgware semi?
A hip-to-gable loft with rear dormer upstairs, a single-storey rear downstairs — separately or as a phased pair. On Edgware's hipped-roof stock they add a lot of space with little planning friction, and both are regulars in Barnet's decisions for the area.
Will I need party wall agreements with my neighbours?
On a semi, almost certainly — works on or near the shared wall engage the Party Wall Act. Budget £1,000–£2,500 per affected neighbour if surveyors get involved, talk to the neighbours early, and we'll handle the formal notices as part of the project.
What we build in Edgware
The same team designs, gets planning and builds — one fixed, itemised price whichever route your Edgware 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
Free site visit
Ready to see what's possible on your street?
Free site visit anywhere in Edgware, honest feasibility advice and a fixed, itemised price — design, planning and build handled end to end by the Pine Grove team.
020 3051 9430Lines open every day, 9am to 8pmMore of North London
Enfield borough
Cockfosters · Oakwood · Southgate · Winchmore Hill · Palmers Green · Enfield · Edmonton · Hadley Wood
Barnet borough
Barnet · East Barnet · New Barnet · Arkley · Monken Hadley · Hampstead Garden Suburb · Whetstone · Totteridge · Finchley · East Finchley · North Finchley · Friern Barnet · Hendon · Golders Green · Mill Hill · Edgware
Haringey borough
Muswell Hill · Highgate · Crouch End · Hornsey · Wood Green · Tottenham
Camden borough
Hackney borough
Hertfordshire border
Potters Bar · Radlett · Shenley · Elstree & Letchmore Heath · Northaw · Cuffley · Brookmans Park · Borehamwood