Covering Devizes
Alongside Devizes, we also cover Calne, Chippenham (9 miles to the north-west) and Trowbridge.
Homes in the South West
In the South West, matching local stone, render or slate is often the main design question, and conservation areas and listed buildings are common in historic towns.
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.
- Steelwork and new floor structure
- Dormer frame, roof covering and cladding
- Staircase, insulation and plasterboard
What is the guide price for a dormer loft conversion in Devizes?
Indicative costs for dormer loft conversions. London and the South East usually sit towards the top of each range.
| 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.
What can change the price or programme?
- 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?
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
Dormer loft conversions: common questions
How long does a dormer conversion take?
Around 8 to 12 weeks on site.
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.
How do I get a price for dormer loft conversions in Devizes?
Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.
Also covering
- Dormer loft conversions in Calne
- Dormer loft conversions in Chippenham
- Dormer loft conversions in Trowbridge
- Dormer loft conversions in Corsham
Learn more about dormer loft conversions, or see every project we cover in Devizes.

