Covering Swanage
Swanage sits 22 miles east of Dorchester, with Poole 7 miles to the north and Bournemouth 8 miles to the north-east.
Homes in the South West
The South West mixes stone and render cottages, Victorian terraces in the larger towns and modern estates, and many historic centres are conservation areas where materials and roof shapes are closely controlled.
What do you get with a dormer loft conversion?
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?
What dormer loft conversions typically cost. These are guide ranges; the written quote for your house replaces them.
| 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 |
How is a dormer loft conversion approved in Swanage?
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. Houses in conservation areas, National Parks and National Landscapes cannot use these roof-extension rights, so dormers there need planning permission (a rooflight-only conversion can still be permitted development), and flats always need permission.
What should Swanage homeowners check first?
- 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?
- 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.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
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.
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 you visit a house in Swanage 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.
Dormer loft conversions near Swanage
- Dormer loft conversions in Poole
- Dormer loft conversions in Bournemouth
- Dormer loft conversions in Christchurch
- Dormer loft conversions in Wimborne Minster
Learn more about dormer loft conversions, or see every project we cover in Swanage.

