Dormer loft conversions in Brighton

Covering Brighton

We work in Brighton (BN2) and the places around it, including Hove, Rottingdean and Burgess Hill.

Homes in the South East

The South East has a lot of 1930s and post-war semi-detached housing, well suited to rear extensions and hip-to-gable loft conversions, alongside period properties in conservation areas that need a more careful design.

What do you get with a dormer loft conversion?

A dormer loft conversion builds a box-shaped extension out from the rear slope of the roof, creating vertical walls and full head height across most of the new floor. It is the most popular type of loft conversion because it gives the most usable space for the cost.

Lawful development certificate or planning drawings
Steelwork and new floor structure
En-suite, electrics and fire-protected escape route

What is the guide price for a dormer loft conversion in Brighton?

Indicative costs for dormer loft conversions. London and the South East usually sit towards the top of each range.

Dormer loft conversions	Guide price incl. VAT
Rear dormer, bedroom only	£50,000 to £65,000
Full-width dormer with en-suite	£60,000 to £80,000
L-shaped dormer (over rear outrigger)	£65,000 to £90,000

What approvals does a dormer loft conversion need in England?

Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.

In England many loft conversions are permitted development: the extra roof volume must stay within 40 m³ on a terraced house or 50 m³ on a semi or detached house, nothing can sit higher than the existing ridge, no dormer can face a road on the main elevation, and side windows must be obscure-glazed and non-opening below 1.7 m. Houses in conservation areas, National Parks and National Landscapes cannot use these roof-extension rights, so dormers there need planning permission (a rooflight-only conversion can still be permitted development), and flats always need permission.

What should Brighton homeowners check first?

Dormers on the front of the house facing a road are not permitted development in England.
A flat dormer roof needs proper falls and a quality membrane.

How does the project run?

Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

What people ask before starting

How much does a dormer loft conversion cost?

Typically £50,000 to £80,000 including VAT, and up to around £90,000 for an L-shaped dormer.

How long does a dormer conversion take?

Around 8 to 12 weeks on site.

How do I get a price for dormer loft conversions in Brighton?

Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.

Dormer loft conversions near Brighton

Learn more about dormer loft conversions, or see every project we cover in Brighton.