Loft conversions · EN5 & EN4
Loft Conversions in Barnet (EN5 & EN4)
Thinking about a loft conversion in Barnet? Most conversions here cost £40,000–£90,000 to build depending on type, almost all are decided by Barnet Council, and the scheme that suits Barnet's 1930s hipped semis is the hip-to-gable conversion with a rear dormer. Book a free site visit and we'll tell you what your roof can take.
Planning in Barnet
Barnet Council's loft approvals and decisions around High Barnet
Barnet Council decides the lofts in High Barnet and Underhill, and it publishes every decision, so you can see how it has ruled on roofs like yours instead of taking a builder's word for what it will accept. The newest loft decisions from those two wards are listed below, each with its result.
Start with the route printed on each card. Lawful development certificate means the owner asked Barnet to confirm the loft was permitted development: a legal check of volume and position, not of looks. Householder application means full planning, and it is the route any dormer inside the Monken Hadley or Wood Street conservation areas has to take. An application marked retrospective was made after the work had been built, which is a risk no loft needs to run.
Recent loft decisions around Barnet
Extension, loft and basement applications decided in Barnet's High Barnet and Underhill wards, 23 Sep 2025 to 22 Sep 2026.
Loft decisions in those wards
- ApprovedAug 2026
Minotaur Drive, EN5
Alteration and conversion of the existing loft space including 2no. front and rear facing rooflights
26/2489/HSE · Barnet CouncilHouseholder application
- RefusedAug 2026
Hadley Highstone, EN5
First floor side extension. Roof extension involving side and rear dormer window (Retrospective Application)
26/1417/RCU · Barnet CouncilHouseholder application
- ApprovedJul 2026
Hyde Close, EN5
Roof extension involving rear dormer window with juliette balcony and 3no. front facing rooflights
26/1968/192 · Barnet CouncilLawful development certificate
- ApprovedJun 2026
Hillside Gardens, EN5
Roof extension involving hip to gable with rear dormer, juliette balcony, 3no. front facing rooflights, new side gable window following…
26/1762/192 · Barnet CouncilLawful development certificate
- ApprovedJun 2026
Minotaur Drive, EN5
Loft conversion within existing roof space with 4 roof slope skylight windows to the front and rear
26/1364/HSE · Barnet CouncilHouseholder application
- RefusedJun 2026
Queens Road, EN5
Single storey side and rear extension. Roof extension including hip to gable, rear dormer window and 3no. rooflights to front roofslope…
26/1612/HSE · Barnet CouncilHouseholder application
- ApprovedMay 2026
Gladsmuir Road, EN5
Single storey side/rear extension following demolition of the existing bay window. Roof extension involving rear dormer window and side…
26/1205/HSE · Barnet CouncilHouseholder application
- ApprovedMay 2026
Fitzjohn Avenue, EN5
Loft
26/1599/192 · 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.
Barnet's rooftops — and which loft suits each
Barnet isn't one roof type; it's three or four, and the right loft depends on which street you're on.
The 1930s semi belt (East Barnet, New Barnet, Oakleigh Park, parts of EN5). This is classic Metroland: bay-fronted, hipped-roof semis. The obvious win here is the hip-to-gable conversion with a rear dormer — claiming the side hip and the dormer together generally yields a roomy double bedroom and en-suite for £55,000–£90,000.
Victorian and Edwardian terraces (High Barnet, around Wood Street and the High Street). Terraces usually have no hip to convert, so the play is a rear dormer across the back slope (£40,000–£75,000), or a mansard where you want maximum floor area and ceiling height (£60,000–£100,000). Mansards reshape the whole rear roof and read sympathetically on a Victorian street.
Larger semis and detached homes (Arkley, Hadley edge, Totteridge fringe). Wider roofs can carry an L-shaped dormer — the main rear dormer plus a return over a back addition — opening up two or three rooms at once (£65,000–£95,000).
Monken Hadley and Wood Street. Both are conservation areas, and inside a conservation area no roof enlargement counts as permitted development, so a dormer or hip-to-gable there needs householder planning permission. Barnet has Article 4 directions in both as well, which also withdraw the permitted development right to make smaller roof alterations such as rooflights. Lofts still happen on these streets; they are simply designed for a conservation officer rather than to a permitted development checklist.
If the ground floor is part of the plan too, our guide to house extensions in Barnet covers rear and side work in EN5, and the loft conversions page walks through each loft type in more detail. Elsewhere in the borough, see our loft guides for Finchley, Hendon and Edgware. Beyond Barnet, our guide to loft conversions across North London takes in Enfield and Haringey as well.
Honest numbers
What a loft conversion costs in Barnet in 2026
These are realistic all-in build ranges for Barnet — labour and materials to a good standard, excluding VAT, fees and loose furnishings:
| Loft type | Typical Barnet 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, Barnet loft costs run £2,800–£4,200 per square metre — North London rates, well above the national average, driven by London labour and the care period homes demand. We quote fixed, itemised prices after a free site visit, so the number you sign is the number you pay.
Permissions, handled
Planning a loft conversion in Barnet
Most Barnet lofts don't need a full planning application. A loft conversion normally counts as permitted development, and the rules give you a roof-volume budget of 40 cubic metres on a terraced house or 50 cubic metres on a semi or detached one — provided the work stays behind the original front roof slope and the materials are in keeping. It's that headroom in the regulations that lets a typical Barnet hip-to-gable proceed as lawful development rather than a full application.
The smart route for most homeowners is a Lawful Development Certificate (£274) — it confirms in writing that your loft was permitted development, which is invaluable when you sell. Where a full application is needed — typically mansards, conservation-area roofs, or homes that have already used up their permitted development rights — the planning fee is £548 (from April 2026) plus the £91.02 portal service charge, and Barnet aims to decide standard householder applications in around eight weeks.
Two other costs to plan for. Building control sign-off runs £500–£1,500. And because most Barnet homes are semi-detached or terraced, the Party Wall Act usually applies — budget £700–£2,500 per neighbour if surveyors are appointed, though it costs nothing if your neighbour consents in writing within 14 days. We prepare the notices as part of the job and start that conversation early.
How it works
How it works
- Free site visit — we come out to your Barnet home, measure the head height, look over the structure, and tell you straight which loft type works, what it'll cost and how planning will go.
- Design & drawings — we draw up full plans and 3D visuals shaped around your particular roof and the way your household uses the space.
- Planning, handled — we put together your certificate or application, lodge it with Barnet Council, and see it through to a decision on your behalf.
- Fixed-price build — Pine Grove's own North London team carries out the work, signs it off through building control, and hands back a finished, tidied space.
Our work
Recent work near Barnet
Our build team's recent North London projects include a full house transformation in Hadley Wood, taking a family home from 120m² to 360m², written up as our Hadley Wood case study. When we visit, tell us what you have in mind for the loft and we'll talk it through against your Barnet roof.
Questions, answered
Barnet loft conversion FAQs
How much does a loft conversion cost in Barnet?
Typically £40,000–£75,000 for a rear dormer, £55,000–£90,000 for a hip-to-gable with rear dormer, and £60,000–£100,000 for a mansard — excluding VAT and fees. Barnet sits on North London rates of roughly £2,800–£4,200/m². Your exact figure comes as a fixed, itemised quote after a free site visit.
Do I need planning permission for a loft conversion in Barnet?
Usually not — most lofts proceed under permitted development, and a hip-to-gable on a typical Barnet semi can usually be designed within the permitted development volume allowance. You'll need a full application for mansards, anything in conservation areas like Monken Hadley or Wood Street, and homes that have already used their permitted development allowance.
What's the best loft for a 1930s semi in East Barnet or New Barnet?
A hip-to-gable with a rear dormer, almost every time. Taking the side hip and the rear slope together usually yields a double bedroom and en-suite on a hipped 1930s roof.
How long does a Barnet loft take to build?
Most are roughly six to ten weeks on site, depending on type and complexity. Design and drawings before that usually take a few weeks; a Lawful Development Certificate is generally quicker than a full application.
Is my Barnet home in a conservation area?
In High Barnet and Underhill the conservation areas to know are Monken Hadley and Wood Street, and both carry Article 4 directions on top of their conservation-area status. During the free consultation, and before a single line is drawn, we cross-reference your address with the council's conservation map to see whether it applies to you.
Nearby areas we cover
Before you start a loft in Barnet
What clients say
Rated 5.0 on Google
Including three reviews from clients in Barnet.
“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.”
“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.”
“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.”
“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.”
“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”
“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.”
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 Barnet, honest feasibility advice and a fixed, itemised price — design, planning and build handled end to end.
Or call us — 020 3051 9430