Loft conversions in Fulham
Dormer, mansard and hip-to-gable conversions adding a bedroom and bathroom.
A rear dormer loft conversion in Fulham costs £55,000–£85,000 and takes 10–14 weeks, adding a double bedroom and en-suite. You need at least 2.2m from the top of the ceiling joists to the underside of the ridge for it to work — measure that before doing anything else.
Consider this if
- You need a fourth bedroom without moving house
- The loft is full of boxes and has a decent ridge height
- You want a principal suite away from the children's rooms
- Neighbours on the street have already converted theirs
- You want to add value before selling
- Working from home needs a room with a door
What's included
- Headroom and structural feasibility checked before you commit
- Steel beams and floor structure designed by a structural engineer
- Staircase designed to Building Regulations, including fire escape route
- Dormer or mansard construction, insulation and roof finishes
- Full en-suite with pumped drainage where needed
- Fire doors, mains-linked alarms and building control sign-off
The standard we build to
Built to Building Regulations Parts A, B (fire), K (stairs) and L, including the protected escape route and 30-minute fire separation a loft conversion legally requires.
Planning position
Rear dormers are often permitted development; mansards and anything to the front usually need planning permission.
| Guide range | £55,000 |
| Typical duration | 10–14 weeks |
| Planning | Hammersmith & Fulham |
Guide ranges for budgeting, excluding VAT and professional fees. We quote a fixed price after a site visit.
Get a fixed priceLoft conversions — what people ask
How much does a loft conversion cost in Fulham?
A rear dormer — the usual choice for a Fulham terrace — is £55,000 to £85,000 excluding VAT, including the en-suite and the staircase. A simple Velux conversion with no structural roof change starts around £45,000. A full mansard, which rebuilds the roof and gives the most space, is £80,000 to £110,000. The London-wide average across all types sits near £50,000 to £90,000.
Read the full answerWhen can you not do a loft conversion?
The deciding factor is headroom. You need at least 2.2m from the top of the existing ceiling joists to the underside of the ridge timber, because once the new floor structure and insulation go in you must retain 2m of usable head height over most of the room. Below about 2.2m a standard conversion will not work — a mansard that rebuilds the roof may still be possible, but it is a much larger job.
Read the full answerIs a loft conversion worth it in Fulham?
Financially, usually yes. A well-executed loft conversion adding a double bedroom and en-suite typically increases a property's value by 10 to 20 percent, and in Fulham — where the price per square metre is high and moving costs including stamp duty are substantial — the uplift often exceeds the build cost. The exception is a house already at the ceiling price for its street.
Read the full answerWhat is the difference between a dormer, mansard and hip-to-gable?
A rear dormer adds a flat-roofed box to the back slope, creating full-height space cheaply — the standard Fulham terrace solution. A mansard rebuilds the whole rear roof at a steep angle, giving the most floor area and usually needing planning permission. A hip-to-gable applies to end-of-terrace and semi-detached houses, squaring off a sloping side roof to create volume, and is often combined with a rear dormer.
Read the full answerDo I need planning permission for a loft conversion?
A rear dormer within permitted development limits (40m³ of added volume on a terrace, 50m³ on a semi or detached, nothing forward of the front roof plane) usually does not. A mansard, a front dormer, or anything in a conservation area normally does. Either way you always need building regulations approval — the fire escape route and staircase requirements are not optional.
Read the full answerLoft conversions across south west London
The housing stock and the planning authority change what is achievable. Each area page covers what is specific to it.
Planning loft conversions in Fulham?
Tell us what you have in mind and we will come back with an honest view on cost, timescale and what is achievable at your address.