Covering Hatfield
Our coverage around Hatfield (AL10) also includes Welwyn Garden City (3 miles to the north) and St Albans.
Homes in the East of England
Across the East of England, newer estates often have integral garages and room for rear extensions, while older towns have Victorian terraces and conservation areas that shape what can be built.
What do you get with 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
- Dormer frame, roof covering and cladding
- 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 |
What approvals does a dormer 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 can affect a dormer loft conversion?
- A flat dormer roof needs proper falls and a quality membrane.
- L-shaped dormers are common on Victorian terraces with a rear outrigger.
From first call to completion
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
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.
What cladding can a dormer have?
Tile-hanging to match the roof, render, slate, timber or zinc, depending on the house and any planning conditions.
Who deals with the council for a project in Hatfield?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Also covering
- Dormer loft conversions in Welwyn Garden City
- Dormer loft conversions in St Albans
- Dormer loft conversions in Potters Bar
- Dormer loft conversions in Hertford
Learn more about dormer loft conversions, or see every project we cover in Hatfield.

