Dormer loft conversions in Cornwall

Covering Cornwall

We cover Cornwall, including Redruth, Falmouth, St Austell and Truro, and the towns around them.

Projects in Cornwall are taken on by arrangement, and any travel and accommodation costs for the team are shown openly in the quote.

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 dormer loft conversion involve?

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.

Lawful development certificate or planning drawings
Steelwork and new floor structure
En-suite, electrics and fire-protected escape route

How much should I budget for a dormer loft conversion?

Typical ranges for dormer loft conversions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.

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 Cornwall

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?

A flat dormer roof needs proper falls and a quality membrane.
L-shaped dormers are common on Victorian terraces with a rear outrigger.

What happens after I enquire?

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.
We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

Questions about a dormer loft conversion in Cornwall

How long does a dormer conversion take?

Around 8 to 12 weeks on site.

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 Cornwall?

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 near Cornwall

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