Dormer loft conversions in Dorset

Covering Dorset

Our coverage across Dorset includes Bournemouth, Poole, Weymouth and Christchurch.

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 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.

Steelwork and new floor structure
Dormer frame, roof covering and cladding
Staircase, insulation and plasterboard

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

Planning and building rules in Dorset

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?

Dormer cheeks close to a shared wall can trigger the Party Wall Act.
L-shaped dormers are common on Victorian terraces with a rear outrigger.

How does the project run?

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.
Construction and completion. One site lead co-ordinates every trade through to the building control certificate.

What people ask before starting

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.

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.

How do I get a price for dormer loft conversions in Dorset?

Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.

Dormer loft conversions in nearby towns

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