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

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 goes into a loft conversion?

We start with the head height. You need roughly 2.2 m or more from the top of the ceiling joists to the underside of the ridge for a conversion to work without raising the roof. From there we design the staircase position, the type of conversion and the en-suite, and manage the whole build including fire safety and building control.

Design drawings and structural calculations
Planning or lawful development certificate
En-suite, electrics, heating and fire safety upgrades

What will a loft conversion cost?

Use these ranges to budget for loft conversions; the survey turns them into a fixed price for the agreed specification.

Loft conversions	Guide price incl. VAT
Rooflight conversion	£30,000 to £45,000
Dormer conversion	£50,000 to £90,000
Hip-to-gable with dormer	£60,000 to £95,000
Mansard conversion	£65,000 to £110,000

How is a loft conversion approved in West Sussex?

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.

What can affect a loft conversion?

The new staircase usually takes space from the landing or a bedroom below.
Party wall notices are often needed for steels bearing on a shared wall.

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.
Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

Loft conversions: common questions

How much does a loft conversion cost?

Roughly £30,000 to £45,000 for a rooflight conversion, £50,000 to £90,000 for a dormer, £60,000 to £95,000 for a hip-to-gable and £65,000 to £110,000 for a mansard, including VAT.

Is my loft suitable for conversion?

If there is about 2.2 m or more from the top of the ceiling joists to the underside of the ridge, it usually is. We check this at the free site visit.

Can you visit a house in West Sussex to quote?

Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.

Loft conversions in nearby towns

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