Dormer loft conversions in Trowbridge

Covering Trowbridge

Trowbridge is about 25 miles south-west of Swindon. We also cover Bath (8 miles to the north-west), Frome and Warminster.

Homes in the South West

Homes in the South West range from coastal and rural properties in stone and slate to city terraces and modern estates, so extensions are designed to match the local materials.

What do you get with 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
Steelwork and new floor structure

How much should I budget for a dormer loft conversion?

Use these ranges to budget for dormer loft conversions; the survey turns them into a fixed price for the agreed specification.

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 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 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.

How does the project run?

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
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.
Construction and completion. One site lead co-ordinates every trade through to the building control certificate.

Dormer loft conversions: common questions

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.

Can a dormer include a bathroom?

Yes. The full head height in a dormer makes it the best place for a shower room or en-suite.

Can you visit a house in Trowbridge to quote?

Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.

Also covering

Learn more about dormer loft conversions, or see every project we cover in Trowbridge.