Loft conversions · NW4
Loft Conversions in Hendon (NW4)
Planning a loft conversion in Hendon? Depending on the type, you're looking at £40,000–£90,000 to build, the planning decision sits with Barnet Council, and the scheme NW4's classic 1930s semis are built for is the hip-to-gable conversion with a rear dormer. Book a free site visit and we'll lay out what your roof can deliver.
Planning in Hendon
What Barnet's approvals mean for an NW4 loft
NW4 sits entirely within Barnet, so a Hendon loft has one council, one set of local policies and one register to read. The newest loft decisions from Barnet's wards here are listed below, whichever way each one went, so you can see how it rules on roofs like yours before anything is drawn.
On a hipped NW4 semi, a hip-to-gable with a rear dormer is normally a certificate job rather than a planning application: Barnet checks the drawings against the permitted development limits and, if they fit, confirms the loft is lawful. A refused certificate is worth reading closely, because it isn't a verdict on design. It means the scheme as drawn broke one of the rules, on volume, materials or something projecting from the front slope, for instance, and a scheme like that can be redrawn or put in as a planning application instead. Inside the Hendon Church End and Hendon The Burroughs conservation areas the certificate route isn't open to a dormer at all.
Recent loft decisions around Hendon
Extension, loft and basement applications decided in Barnet's Hendon and West Hendon wards, 23 Sep 2025 to 22 Sep 2026.
Loft decisions in those wards
- ApprovedAug 2026
Wykeham Road, NW4
Roof extension involving box dormer infill to second floor balcony area. Roof extension to adjoin roof of existing two storey rear…
26/2791/192 · Barnet CouncilLawful development certificate
- ApprovedAug 2026
Dartmouth Road, NW4
Roof extension involving rear dormer windows and 3no. front facing rooflights, with internal alterations.
26/3083/192 · Barnet CouncilLawful development certificate
- ApprovedAug 2026
Layfield Road, NW4
Roof extension involving hip to gable, rear dormer window and 2no. front facing rooflights
26/2756/192 · Barnet CouncilLawful development certificate
- RefusedAug 2026
Tenterden Drive, NW4
Roof extension involving hip to gable, rear dormer window and 4no. front facing rooflights
26/2249/192 · Barnet CouncilLawful development certificate
- ApprovedAug 2026
Boyne Avenue, NW4
Roof extension involving rear dormer window and 2no. front facing rooflights
26/2815/192 · Barnet CouncilLawful development certificate
- ApprovedJul 2026
Hendon Way, NW4
Roof extension involving rear dormer window and 3no. front facing rooflights. Removal of chimney on rear elevation
26/2066/192 · Barnet CouncilLawful development certificate
- ApprovedJul 2026
Brent View Road, NW9
Roof extension involving rear dormer window and 3no. front facing rooflights
26/2600/192 · Barnet CouncilLawful development certificate
- ApprovedJul 2026
Park Road, NW4
Roof extension involving rear dormer window with juliette balcony and 2no. front facing rooflights. New front porch
26/2572/192 · 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.
Hendon's rooftops — and which loft suits each
Hendon's housing is varied, but one roof type dominates.
The 1930s hipped semis (the bulk of NW4). This is the heart of Hendon: Metroland semis with hipped roofs. The scheme that earns its place here is the hip-to-gable conversion with rear dormer — claiming the side hip together with the dormer to give you a double bedroom and en-suite for £55,000–£90,000.
Larger semis and detached homes (around Hendon Hall and the leafier roads). A broader roof brings the L-shaped dormer within reach — a rear dormer matched with a return over an original back addition — so the loft yields two or three usable rooms in one go (£65,000–£95,000).
Terraced and townhouse pockets (around the Burroughs and newer infill). Without a hip to convert, a rear dormer does the job (£40,000–£75,000); a mansard is the route when you need maximum floor area and reshaping the whole rear roof is justified (£60,000–£100,000). The Burroughs itself is a conservation area, so a dormer there needs full planning permission, and where its Article 4 direction applies rooflights do too.
Where head height already works. A Velux conversion leaves the external roof as it stands and keeps the outlay at £30,000–£45,000 — a sensible pick for a study or a single bedroom.
The ground-floor side of a Hendon project is on our house extensions in Hendon page, and if you want to weigh up the loft types first, loft conversions covers each one. To see Hendon next to the other towns we cover, read our guide to loft conversions across North London.
Honest numbers
What a loft conversion costs in Hendon in 2026
What follows are realistic all-in build ranges for Hendon — labour and materials to a sound standard, before VAT, fees and loose furnishings are added:
| Loft type | Typical Hendon cost | On-site time | Usual planning route |
|---|---|---|---|
| Velux / rooflight conversion | £30,000 – £45,000 | 6–8 weeks | Permitted development |
| Rear dormer | £40,000 – £75,000 | 6–9 weeks | Usually permitted development |
| Hip-to-gable + rear dormer | £55,000 – £90,000 | 7–10 weeks | Usually permitted development |
| L-shaped dormer | £65,000 – £95,000 | 8–10 weeks | Usually permitted development |
| Mansard | £60,000 – £100,000 | 8–10 weeks | Often a full application |
As a rule of thumb, Hendon loft costs run £2,800–£4,200 per square metre — North London rates, well above the national average. Everything goes into a fixed, itemised quote after the free site visit, so there are no surprises on the final bill.
Permissions, handled
Planning a loft conversion in Hendon
Most Hendon lofts don't need a full planning application. A conversion typically qualifies as permitted development, and the volume you're permitted to add depends on the house: up to 50 cubic metres for a semi or detached home and 40 cubic metres for a terrace, with the firm proviso that nothing projects in front of the original front roof slope. That generous allowance on a Metroland semi is why a hip-to-gable here can often go ahead as a roof extension without a full application.
A Lawful Development Certificate (£274) is the document most NW4 owners should secure — it records officially that the loft qualified as permitted development, and that proof earns its keep the moment a buyer's solicitor starts asking questions. When a full application can't be sidestepped — a mansard, a conservation-area roof, or a home that has spent its allowance — the cost is £548 (from April 2026) plus the £91.02 portal service charge, and Barnet works to a target of around eight weeks on standard householder decisions.
Two further outlays to plan for. Building control will charge £500–£1,500 to inspect and certify the finished work. Then there's the Party Wall Act: Hendon's housing being so heavily semi-detached, it applies to most jobs in NW4, so pencil in £700–£2,500 per neighbour where surveyors are brought in — yet nothing at all is owed if a neighbour signs their agreement within 14 days. We issue the notices for you and time them so the build keeps moving.
How it works
How it works
- Free site visit — we survey your Hendon roof, weigh up the head height and the structure, and give you a frank read on the right loft, the likely cost and the planning route ahead.
- Design & drawings — full working plans and 3D visuals, drawn around the shape of your roof and the way your household uses the space.
- Planning, handled — we put together your certificate or application, lodge it with Barnet Council, and steer it all the way through to a decision.
- Fixed-price build — our own team at Pine Grove builds it, has it signed off by building control and hands it back to you clean and finished.
Our work
Recent work near Hendon
Our build team's recent North London work includes a Hadley Wood house transformation that took a family home from 120m² to 360m² — it's written up as the Hadley Wood case study. When we visit, we'll talk through how a hip-to-gable would work on a hipped NW4 semi like yours.
Questions, answered
Hendon loft conversion FAQs
How much does a loft conversion cost in Hendon?
On NW4's typical hipped semi a hip-to-gable with rear dormer runs £55,000–£90,000. A plain rear dormer is £40,000–£75,000 and a mansard £60,000–£100,000, both excluding VAT and fees. Like the rest of North London, Hendon works out at roughly £2,800–£4,200/m². We pin down your exact price in a fixed, itemised quote after a free site visit.
Do I need planning permission for a loft conversion in Hendon?
In most cases no — the bulk of lofts go ahead as permitted development, and a hip-to-gable on an NW4 semi usually fits within the volume allowance. You'll only need a full application for mansards, conservation-area roofs and homes that have already used their permitted development allowance.
What's the best loft for a 1930s semi in Hendon?
For NW4's textbook Metroland semis, a hip-to-gable with a rear dormer. By bringing the redundant side hip and the rear slope into play together, it makes a full double room with standing headroom.
How long does a Hendon loft take to build?
Most NW4 hip-to-gable conversions sit around seven to ten weeks on site; lighter rooflight schemes wrap up sooner. Factor in the design and drawings stage at the outset, and note that a Lawful Development Certificate usually clears more quickly than a full application.
Is my Hendon home in a conservation area?
The ones to know here are Hendon Church End and Hendon The Burroughs, the second with an Article 4 direction as well. At the free consultation, before a single line is drawn, we look your address up on the council's conservation map to see whether yours is in either.
Nearby areas we cover
Before you start a loft in Hendon
What clients say
Rated 5.0 on Google
“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.”
“Excellent experience with The Extension Company. They completed our loft conversion and delivered exactly what they promised. The new bedroom and en-suite have added valuable space to our property in Barnet, the quality of the workmanship is first class. The team were friendly, knowledgeable and always happy to answer questions throughout the build.”
“Couldn't be happier with our loft conversion. We were expecting the build to be stressful, but it was actually a lot easier than we'd imagined. The lads were friendly, worked hard, and the quality of the finish is spot on. The extra room has made a massive difference and has given us the space we needed without having to move. Very pleased with the end result.”
“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”
Reviews shown word for word from our Google profile. See 9 more client reviews · Read all 16 reviews on Google
Ready to see what's possible on your street?
Free site visit anywhere in Hendon, honest feasibility advice and a fixed, itemised price — design, planning and build handled end to end.
Or call us — 020 3051 9430