Covering Trowbridge
Our coverage around Trowbridge (BA14) also includes Bath (8 miles to the north-west) and Frome.
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 does a loft conversion involve?
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.
- Design drawings and structural calculations
- New floor joists, steels and staircase
- Dormer or rooflights, insulation and plasterboard
How much does a loft conversion cost in Trowbridge?
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 |
How is a loft conversion approved in Trowbridge?
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 should I think about before starting?
- Head height under the ridge decides whether a conversion is practical.
- Fire safety rules can mean new fire doors on the floors below.
From first call to completion
- 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.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
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.
Who deals with the council for a project in Trowbridge?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Loft conversions in nearby towns
- Loft conversions in Bath
- Loft conversions in Frome
- Loft conversions in Warminster
- Loft conversions in Corsham
Learn more about loft conversions, or see every project we cover in Trowbridge.

