Dormer loft conversions in West Sussex

Covering West Sussex

We cover West Sussex, including Crawley, Worthing, Bognor Regis and Littlehampton, and the towns around them.

Homes in the South East

Many South East homes are inter-war or post-war semis and detached houses with room for rear and side extensions, while historic town centres and villages bring conservation area and listed building controls.

What does a dormer loft conversion involve?

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.

Volume calculation and permitted development check
Lawful development certificate or planning drawings
Staircase, insulation and plasterboard

What will a dormer loft conversion cost?

Guide prices for dormer loft conversions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.

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

Planning and building rules in West Sussex

In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it 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.

What can affect a dormer loft conversion?

Dormers on the front of the house facing a road are not permitted development in England.
L-shaped dormers are common on Victorian terraces with a rear outrigger.

From first call to completion

Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
Construction and completion. One site lead co-ordinates every trade through to the building control certificate.

Your questions answered

How long does a dormer conversion take?

Around 8 to 12 weeks on site.

Can a dormer include a bathroom?

Yes. The full head height in a dormer makes it the best place for a shower room or en-suite.

Who deals with the council for a project in West Sussex?

We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.

Other towns nearby

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