Dormer loft conversions in Beckenham

Covering Beckenham

We work in Beckenham (BR3) and the places around it, including Catford, Croydon and Blackheath.

Homes in London

Much of London’s housing is Victorian and Edwardian terraces, which is why side return extensions, rear dormers and mansards are so common. Many streets are in conservation areas, and several boroughs use Article 4 directions that remove some permitted development rights.

What does a dormer loft conversion involve?

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
En-suite, electrics and fire-protected escape route

How much should I budget for a dormer loft conversion?

Indicative costs for dormer loft conversions. London and the South East usually sit towards the top of each range.

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 change the price or programme?

Dormers on the front of the house facing a road are not permitted development in England.
Dormer cheeks close to a shared wall can trigger the Party Wall Act.

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

What people ask before starting

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.

Who deals with the council for a project in Beckenham?

We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.

Dormer loft conversions in nearby towns

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