Covering Chippenham
Alongside Chippenham, we also cover Corsham, Calne (5 miles to the east) and Devizes.
Homes in the South West
The South West mixes stone and render cottages, Victorian terraces in the larger towns and modern estates, and many historic centres are conservation areas where materials and roof shapes are closely controlled.
What goes into a dormer loft conversion?
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
- Staircase, insulation and plasterboard
- En-suite, electrics and fire-protected escape route
How much does a dormer loft conversion cost in Chippenham?
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 |
What approvals does a dormer loft conversion need in England?
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?
- Dormer cheeks close to a shared wall can trigger the Party Wall Act.
- A flat dormer roof needs proper falls and a quality membrane.
How does the project run?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- 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.
Your questions answered
Is a dormer permitted development?
Rear dormers in England often are, within the 40 m³ (terrace) or 50 m³ (semi or detached) volume allowance. Front dormers facing a road are not.
How long does a dormer conversion take?
Around 8 to 12 weeks on site.
Do you work in Chippenham?
Yes. Chippenham is within our coverage for dormer loft conversions, along with nearby Corsham and Calne.
Dormer loft conversions near Chippenham
- Dormer loft conversions in Corsham
- Dormer loft conversions in Calne
- Dormer loft conversions in Devizes
- Dormer loft conversions in Trowbridge
Learn more about dormer loft conversions, or see every project we cover in Chippenham.

