Loft conversions in Brentwood
Brentwood houses convert differently to London ones, and the reason is space. Plots here are wider, detached and semi-detached homes are far more common than terraces, and roofs tend to be shallower and more modern. That changes which conversion makes sense and what it costs.
We design and build loft conversions across Brentwood, Shenfield, Hutton, Ingatestone and the surrounding Essex villages, handling drawings, structural calculations, Building Regulations and the build with one team.
What Brentwood roofs will take
1930s and post-war semis. Common through central Brentwood and Hutton. Hipped roofs are the norm, with the side slope eating into usable volume. A hip-to-gable squares that off, and paired with a rear dormer it opens up the whole floor.
Detached homes on larger plots. Shenfield and the outer villages have a lot of these. Wider frontages mean a dormer can run the full rear width without looking heavy, and there is usually room to position a staircase properly rather than squeezing it in.
Newer estate housing. Anything built from the 1960s onward is likely to have a trussed roof, with webbing running through the loft carrying the structure. These convert, but the trusses have to be removed and replaced with steel, which adds several thousand pounds. Shallow pitches on some estates rule a conversion out, and we will tell you if yours is one of them.
Period cottages and village properties. Ingatestone and the surrounding villages have older stock where the roof may be listed or in a conservation area. These need a different approach and often a different conversion type.
Which conversion suits your house
| Your property | Usual conversion | What you gain | Typical cost |
|---|---|---|---|
| 1930s semi, hipped roof | Hip-to-gable with rear dormer | Bedroom with room for an en-suite | £58,000 to £75,000 |
| Detached, wide rear elevation | Full-width rear dormer | Two rooms or a large master suite | £55,000 to £72,000 |
| Semi or detached, good head height | Velux | One room, roofline unchanged | £38,000 to £48,000 |
| Estate housing, trussed roof | Dormer with steel replacement | A usable floor where there was none | £55,000 to £70,000 |
| Village or period property | Assessed individually | Depends on the roof and any designation | Quoted after survey |
Essex ranges for 2026, before VAT, professional fees and any en-suite. The loft conversion cost guide breaks each type down further.
Planning permission in Brentwood
Brentwood Borough Council handles planning here, and the position is generally more relaxed than in inner London, largely because there are fewer dense terraces with protected rooflines.
Most rear dormers and Velux conversions fall under Permitted Development: 50 cubic metres of added volume on a semi-detached or detached house, 40 on a terrace, and nothing forward of the original roof slope on the elevation facing a highway.
Two local factors are worth checking early. Parts of the borough sit within green belt, which brings tighter control over extensions and alterations, and the conservation areas in Brentwood town, Shenfield and the villages restrict Permitted Development rights.
A hip-to-gable is the one to watch. Where the gable end would face a highway, it usually needs a planning application even though a rear dormer on the same house would not.
Building Regulations approval is required on every conversion regardless of the planning route.
Areas we cover around Brentwood
Brentwood town, Shenfield, Hutton, Ingatestone, Warley, Pilgrims Hatch, Doddinghurst, Blackmore and the surrounding villages.
We also cover North London and East London, including Chingford and Romford.
What a Brentwood conversion costs
Essex pricing sits slightly below inner London for the same work, mostly because access is easier and there is usually somewhere to put a skip and a scaffold without a highways licence.
A Velux conversion runs from around £38,000, a rear dormer £48,000 to £62,000, and a hip-to-gable with dormer £58,000 to £75,000. Larger detached properties with wide rear elevations sit at the top of those ranges simply because there is more of everything to build.
On top of the build, budget for VAT at 20 percent, architectural drawings, structural calculations, Building Regulations, and a party wall surveyor if you are semi-detached. Together those usually add 20 to 30 percent again, and we set all of it out before you commit.
How the work runs
Survey first. Head height from ceiling joist to ridge, roof structure, pitch and the staircase position below. That decides what is actually available to you.
Design and structure in-house. The drawings that go to Building Control are the ones we build from.
Approvals. Building Regulations on every project, planning where needed, and party wall notices on semi-detached properties.
Build. One project manager, a fixed price agreed up front, payments tied to stages rather than dates.
Loft conversions in Brentwood: frequently asked questions
How much does a loft conversion cost in Brentwood?
Between £38,000 and £85,000 in 2026 depending on type. A Velux starts around £38,000, a rear dormer runs £48,000 to £62,000, and a hip-to-gable with dormer £58,000 to £75,000.
Do I need planning permission for a loft conversion in Brentwood?
Usually not for a rear dormer or Velux conversion within the volume limits. A hip-to-gable facing a highway, anything in a conservation area, and green belt properties are more likely to need an application.
Which conversion suits a 1930s semi in Brentwood?
Usually a hip-to-gable, often combined with a rear dormer. The hipped side roof wastes internal volume and squaring it off recovers the space.
Can a house with a trussed roof be converted?
Yes, but it costs more. The trusses carry the roof, so they are removed and replaced with steel beams and new floor structure. Budget several thousand pounds above a comparable cut-roof conversion.
How long does a loft conversion take in Brentwood?
Four to six weeks on site for a Velux, six to eight for a rear dormer, eight to twelve for a hip-to-gable. Add design time and any planning period beforehand.
Planning a loft conversion in Brentwood?
Send us your address and a rough idea of what the space is for. We will come back with the conversion your roof will actually take, a realistic cost range, and whether Brentwood Borough Council is likely to want an application. No price until we have seen the roof.
