Covering Catford
Alongside Catford, we also cover Blackheath, Greenwich (2 miles to the north) and Beckenham.
Homes in London
London projects often mean working on period terraces with neighbours on both sides, tight access through the house and conservation area controls, so careful planning and party wall work matter as much as the build.
What goes into 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
- Dormer frame, roof covering and cladding
- En-suite, electrics and fire-protected escape route
What will a dormer loft conversion cost?
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 |
What approvals does a dormer loft conversion need in England?
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?
- Dormers on the front of the house facing a road are not permitted development in England.
- A flat dormer roof needs proper falls and a quality membrane.
What happens after I enquire?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- 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.
Your questions answered
How much does a dormer loft conversion cost?
Typically £50,000 to £80,000 including VAT, and up to around £90,000 for an L-shaped dormer.
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.
Do you work in Catford?
Yes. Catford is within our coverage for dormer loft conversions, along with nearby Blackheath and Greenwich.
Other towns nearby
- Dormer loft conversions in Blackheath
- Dormer loft conversions in Greenwich
- Dormer loft conversions in Beckenham
- Dormer loft conversions in Peckham
Learn more about dormer loft conversions, or see every project we cover in Catford.

