Area guide · NW4
House Extensions in Hendon (NW4)
Planning a house extension in Hendon? We design, gain planning permission and build extensions and loft conversions across NW4 — from the 1930s semi streets to the Edwardian terraces around Hendon Central. The going rate to build a single-storey rear is £45,000–£90,000, applications go through Barnet Council, and the hip-to-gable loft conversion is tailor-made for Hendon's hipped-roof semis. Let us walk your 1930s semi with you on a free site visit — by the end of it you'll know exactly what your street will take.
Planning in Hendon
What Barnet Council approves on Hendon's semis
Barnet's published decisions make the pattern visible before you spend a penny on drawings. The dated list on this page draws on two Barnet wards, Hendon and West Hendon, and it shows how the council has recently ruled on NW4 houses: rear extensions, roof extensions, garage conversions and porches, with the refusals left in.
Expect the odd NW9 address among the NW4 ones. West Hendon ward runs west across the postcode line towards the Edgware Road, so some of its houses carry NW9 postcodes while still being Barnet's to decide. Expect a mix of routes, too. Rear extensions of 6m arrive as prior approvals, most roof schemes as lawful development certificates, and anything with a front extension, a two-storey side element or a conservation-area address as a full householder application.
On Hendon's bay-fronted, hipped-roof semis, the rear extension and the hip-to-gable loft are the staple schemes, and both are well represented in the list. If that's the project you have in mind, you're in well-trodden territory — and we design to that grain.
Recent planning decisions around Hendon
Extension, loft and basement applications decided in Barnet's Hendon and West Hendon wards, 23 Sep 2025 to 22 Sep 2026.
The newest decisions in those wards
- ApprovedSep 2026
West View, NW4
Part single part two storey rear extension with pitched roof. Roof extension involving hip to gable, rear dormer window and 2no. front…
26/2605/HSE · Barnet CouncilHouseholder application
- ApprovedSep 2026
Hyde Crescent, NW9
Single storey rear extension with a proposed depth of 6.00 metres, maximum height of 4.00 metres and eaves height of 3.00 metres.
26/2990/PNH · Barnet CouncilPrior approval, larger home extension
- ApprovedSep 2026
Renters Avenue, NW4
Part single, part two storey side and rear extension. Erection of single storey outbuilding following demolition of the existing garage
26/2527/HSE · Barnet CouncilHouseholder application
- ApprovedSep 2026
Sturgess Avenue, NW4
Single storey rear extension
26/2720/HSE · Barnet CouncilHouseholder application
- RefusedSep 2026
Dartmouth Road, NW4
Single storey rear extension infill with 2no. rooflights
26/3084/192 · Barnet CouncilLawful development certificate
- ApprovedSep 2026
Greyhound Hill, NW4
Single storey front extension incorporating a front porch including conversion of garage into habitable room, insertion of window to…
26/2477/HSE · Barnet CouncilHouseholder application
- ApprovedSep 2026
Layfield Crescent, NW4
Single storey rear extension with a proposed depth of 6.00 metres, maximum height of 3.00 metres and eaves height of 3.00 metres…
26/2739/PNH · Barnet CouncilPrior approval, larger home extension
- ApprovedSep 2026
Boyne Avenue, NW4
2no single storey rear extensions with a maximum depth of 6.00m, maximum height of 3.90m and an eaves height 3.00m
26/2816/PNH · Barnet CouncilPrior approval, larger home extension
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
Hendon's housing stock — and what works on each
Hendon reads as one suburb on a map, but it's really three or four distinct markets — and the right extension depends on which one you're in.
The 1930s semi streets (most of NW4). Hendon's signature stock: hipped-roof, bay-fronted semis with side passages and proper gardens, built in the great interwar push along the Northern line. This is textbook hip-to-gable and 6-metre-rear territory. A hip-to-gable loft with rear dormer converts the wasted hip into a full double bedroom and en-suite for £55,000–£90,000; the Hendon loft conversion guide takes the roof options one by one. A single-storey rear extension — 3m deep under standard permitted development, up to 6m with larger-home prior approval — opens the kitchen to the garden for £45,000–£90,000. Do both, together or phased, and a three-bed semi becomes a five-bed family house without anyone changing school.
Edwardian terraces around Hendon Central. The older streets near the station are narrower, with rear closet wings — classic side-return extension territory (£35,000–£65,000), reclaiming the dead alley beside the kitchen for a full-width kitchen-diner, or a wrap-around (£70,000–£140,000) if you take the rear as well. Terraces mean party wall agreements with both neighbours; we manage that paperwork as part of the job.
The Burroughs and the historic core. The Burroughs is Hendon's civic and historic heart — Georgian frontages, the old town hall, the library and the Middlesex University campus give this pocket a character the rest of NW4 doesn't share. Older, more sensitive properties here reward careful design and honest materials, and planning is less of a formality. The section below sets out the two conservation areas that cover this part of Hendon.
The Brent Cross effect. With the vast Brent Cross regeneration reshaping the area next door, the maths in Hendon increasingly favours extending over moving: add 20–40m² to the house you own, in an area on the way up, and you keep your street, your schools and your commute while the house grows around you.
Every street is different. That's the point.
We design to Hendon'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 estimateHendon's two conservation areas
Barnet designated two conservation areas in Hendon ward in 1983: Hendon The Burroughs, around the civic buildings, and Hendon Church End, the old village core around the parish church to the north of it.
What they mean for a ground-floor extension is different. In both, the national rules take side extensions, two-storey rear extensions and the larger-home prior approval route out of permitted development, and a dormer always needs planning permission. The Burroughs goes further in places: an Article 4 direction made in 1987 covers parts of it and withdraws the right to extend the house (Part 1, Class A), along with porches, outbuildings, hard surfaces, and boundary walls and gates, so on those houses even a modest single-storey rear needs a planning application. planning.data.gov.uk shows no Article 4 direction on Hendon Church End, where a small rear extension within the standard limits can still be permitted development.
For a house in either, the application is judged on how it sits with the conservation area's character: materials, roof form, and how much of it can be seen from the street. Our conservation area guide covers the design side.
Honest numbers
What a house extension costs in Hendon in 2026
Genuine Hendon build figures sit in the bands below — well-executed labour and materials, with VAT, professional fees and kitchen fit-out on top:
| Extension type | Typical Hendon 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 |
Hendon builds at the standard North London rate of £2,800–£4,200 per square metre — straight multiplication puts a 20m² rear addition at £56,000–£84,000 of build cost. After the free site visit we commit to a fixed, fully itemised price, and it stays put: no creep between contract and completion.
Permissions, handled
Planning permission in Hendon — what you need to know
Most Hendon extensions don't need a full planning application. The PD baseline grants 3m of rear extension depth on semis and terraces and 4m on detached homes; through the larger home extension scheme that stretches to 6m (8m detached), with the council consulting your neighbours under prior approval instead of running a full application. Loft conversions enjoy a generous volume allowance, which is why so many hip-to-gable schemes in NW4 go through as lawful development.
Where you do need permission: double-storey and wrap-around schemes, flats and maisonettes, most work in Hendon's two conservation areas — where permitted development rights are restricted — and houses where a previous owner has already used the PD allowance, which is common on streets that have been extending since the 1980s. Allow around eight weeks for Barnet to determine a standard householder application.
Party walls: Hendon is overwhelmingly semi-detached and terraced, so the Party Wall Act applies to most projects. Budget £1,000–£2,500 per affected neighbour if surveyors are appointed — and have the friendly conversation over the fence early; it keeps things smooth and inexpensive. We serve the notices for you.
Our approach: we design to what Barnet Council demonstrably approves, and when the lawful development route makes better sense we'll secure the certificate for you — the piece of paper that heads off awkward questions at remortgage or sale. Hendon is one of the Barnet towns in our guide to house extensions across North London, which sets each council's rules side by side.
How it works
How it works
- Free site visit — we walk your hipped-roof Hendon semi (or your Edwardian terrace near the station), hear the plan, and respond with honest numbers and a clear route.
- Design & drawings — proper drawings and 3D views, composed around your floor plan and the way your family uses it.
- Planning, handled — we take the whole Barnet Council process off your hands, from preparing the file to chasing the decision.
- Fixed-price build — execution by our dependable North London crew, wrapped up with building control certification and a genuinely tidy exit.
Our work
Recent work near Hendon
Among our build team's latest North London completions is a full house transformation in Hadley Wood, taking a family home from 120m² to 360m², written up as the Hadley Wood case study. Say the word at your Hendon site visit and we'll show you how it came together.
Questions, answered
Hendon extension FAQs
What should I budget for a house extension in Hendon?
Around £45,000–£90,000 for a single-storey rear extension, £55,000–£90,000 for a hip-to-gable loft and £18,000–£35,000 for a garage conversion — excluding VAT and fees, on NW4 build rates of £2,800–£4,200 per square metre. Every quote we give is fixed and itemised after a free site visit.
Can I really extend 6 metres without full planning permission?
On most Hendon semis, yes. The larger home extension scheme allows rear extensions up to 6m (8m on detached houses) through prior approval, where Barnet Council consults your neighbours instead of running a full application. It isn't open to houses in a conservation area, so we confirm your house qualifies before any design work begins.
Is a hip-to-gable loft the right move for a 1930s Hendon semi?
Almost always. NW4's hipped roofs are the exact stock it suits, and the generous permitted development volume allowance typically delivers a double bedroom plus en-suite without a full application.
Does the Brent Cross regeneration change the case for extending?
It strengthens it. With the area beside NW4 improving and the cost of moving high, adding space to the house you already own is increasingly the better-value route — and well-extended semis hold their value strongly in improving areas.
What about older houses near The Burroughs?
Many are inside the Hendon The Burroughs conservation area, and on the houses its Article 4 direction covers, even a single-storey rear extension needs planning permission. Proportions, rooflines and materials carry real weight there. We check your address against Barnet's conservation map at the free consultation, before you spend anything.
Which parts of Hendon do you cover?
All of NW4 — Hendon Central, West Hendon, the streets around The Burroughs and Middlesex University, and the Brent Cross side — plus neighbouring Mill Hill, Golders Green, Finchley and Edgware.
What we build in Hendon
The same team designs, gets planning and builds — one fixed, itemised price whichever route your Hendon 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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