What is a dormer loft conversion?
A dormer loft conversion adds a box-shaped structure to the rear roof slope, creating vertical walls and full headroom across most of the new room. It is the most common loft conversion in the UK because it works on terraced, semi-detached and detached houses.
How much does a dormer loft conversion cost in Melksham?
In Melksham, a dormer loft conversion typically costs £49,000–£69,500 for a typical rear dormer with en-suite, including VAT at 20% (standard rate). Prices in the South West sit near the national average for this kind of work, and the range for Melksham reflects that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear dormer with en-suite | £49,000–£69,500 |
| Higher specification | £69,500–£87,000 |
What moves the price most:
- Scaffolding and access
- Staircase position
- Dormer size and roof structure
- En-suite or bathroom
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a dormer loft conversion in Melksham?
Whether you need planning permission depends on your house and its location in England. In England a rear dormer is often permitted development if the extra roof volume is no more than 40 cubic metres on a terraced house or 50 on other houses, it does not face the road, sits no higher than the ridge and is set back from the eaves, with matching materials and obscure-glazed side windows. Balconies, front dormers and work in conservation areas need planning permission.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
We check this for your address before design work starts, so there are no surprises later.
What we handle
The work we manage on a dormer loft conversion:
- Drawings and structural calculations
- New staircase and fire-safe escape route
- Building control completion certificate
- Measured survey and head-height check
- Party wall notices for shared walls
- Steel beams and new floor joists
How long does it take?
Expect 6 to 9 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Melksham
The South West mixes stone and render cottages with post-war and newer estates, and local materials matter more here when matching an extension.
From SN12 outwards, we take on projects throughout Melksham and the surrounding parts of Wiltshire.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about dormer loft conversions in Melksham
How much head height do I need?
Ideally at least 2.2 metres from the top of the ceiling joists to the underside of the ridge. Less can still work with a dormer, but we check this at the survey.
How long does it take?
Usually 6 to 9 weeks on site.
Who approves a dormer loft conversion in Melksham?
Planning matters in Melksham go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
What fire safety is required?
Building regulations require a safe escape route. Converting a two-storey house to three storeys usually means a protected stairway with fire doors to habitable rooms and mains-wired smoke alarms.
How much does a dormer loft conversion cost in Melksham?
In Melksham, a dormer loft conversion typically costs £49,000–£69,500 for a typical rear dormer with en-suite, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.