Covering Northampton
Our coverage around Northampton (NN1) also includes Wellingborough, Towcester and Daventry.
Homes in the East Midlands
Across the East Midlands you find everything from city terraces to modern estates and stone villages, so the right extension depends a lot on the street and the materials around it.
What goes into a dormer loft conversion?
Rear dormers on terraced and semi-detached houses are often permitted development in England. We size the dormer to fit the volume allowance, clad it to suit the house (tile-hanging, render, slate or zinc) and fit out the room and en-suite below.
- Volume calculation and permitted development check
- Lawful development certificate or planning drawings
- En-suite, electrics and fire-protected escape route
What will a dormer loft conversion cost?
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 |
Do you need permission for a dormer loft conversion in Northampton?
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. 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?
- Dormer cheeks close to a shared wall can trigger the Party Wall Act.
- A flat dormer roof needs proper falls and a quality membrane.
What are the steps?
- 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.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Dormer loft conversions: common questions
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 Northampton?
Yes. Northampton is within our coverage for dormer loft conversions, along with nearby Wellingborough and Towcester.
Also covering
- Dormer loft conversions in Wellingborough
- Dormer loft conversions in Towcester
- Dormer loft conversions in Daventry
- Dormer loft conversions in Rushden
Learn more about dormer loft conversions, or see every project we cover in Northampton.