Loft conversions in Portsmouth

Covering Portsmouth

Our coverage around Portsmouth (PO5) also includes Gosport (2 miles to the west) and Fareham.

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 is included in a loft conversion in Portsmouth?

A loft conversion turns an unused roof space into habitable rooms, usually a bedroom with an en-suite, by strengthening the floor, adding a staircase, insulating the roof and putting in windows. The type you need depends on the roof: rooflight, dormer, hip-to-gable or mansard.

Design drawings and structural calculations
New floor joists, steels and staircase
Dormer or rooflights, insulation and plasterboard

What is the guide price for a loft conversion in Portsmouth?

Typical ranges for loft conversions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.

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

Do you need permission for a loft conversion in Portsmouth?

English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.

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 should I think about before starting?

Fire safety rules can mean new fire doors on the floors below.
Party wall notices are often needed for steels bearing on a shared wall.

From first call to completion

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

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.

Do I need fire doors?

Often yes. Building regulations require a protected escape route from the new floor, which usually means fire doors on to the stairs and linked smoke alarms.

How do I get a price for loft conversions in Portsmouth?

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

Other towns nearby

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