Covering Hounslow
Alongside Hounslow, we also cover Isleworth, Heston (1 miles to the north-west) and Richmond.
Homes in London
London projects often mean working on period terraces with neighbours on both sides, tight access through the house and conservation area controls, so careful planning and party wall work matter as much as the build.
What is a loft conversion?
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.
- Loft survey and head-height check
- Design drawings and structural calculations
- Planning or lawful development certificate
How much does a loft conversion cost in Hounslow?
Indicative costs for loft conversions. London and the South East usually sit towards the top of each range.
| 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 Hounslow?
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 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
- 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.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
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 Hounslow?
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
- Loft conversions in Isleworth
- Loft conversions in Heston
- Loft conversions in Richmond
- Loft conversions in Hanworth
Learn more about loft conversions, or see every project we cover in Hounslow.

