Covering Sunbury-on-Thames
Our coverage around Sunbury-on-Thames (TW16, TW17) also includes Walton-on-Thames (1 miles to the south) and Hanworth.
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 loft conversion involve?
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
- En-suite, electrics, heating and fire safety upgrades
What is the guide price for a loft conversion in Sunbury-on-Thames?
Guide prices for loft conversions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.
| 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 |
What approvals does a 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 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.
What are the steps?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- 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.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Questions about a loft conversion in Sunbury-on-Thames
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.
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.
Who deals with the council for a project in Sunbury-on-Thames?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Loft conversions near Sunbury-on-Thames
- Loft conversions in Walton-on-Thames
- Loft conversions in Hanworth
- Loft conversions in Ashford
- Loft conversions in Feltham
Learn more about loft conversions, or see every project we cover in Sunbury-on-Thames.

