Extensions · Loft conversions
Loft conversion in London, from drawings to the last stair.
A loft conversion is structure, fire safety and a new staircase before it is a bedroom. We coordinate the drawings, approvals, steelwork and every trade, on one fixed written quote.
What a London
loft conversion includes.
Measured survey, drawings, planning or a lawful development certificate, and Building Control.
New floor joists, steel beams and the dormer or gable built to the engineer's design.
A new stair, fire doors and mains linked smoke alarms forming the escape route.
Roof insulated to current standards, then tiled or slated to match.
Electrics, plumbing for an ensuite, plastering, flooring and decoration.
Survey, approval,
build, sign off.
We measure the loft, check head height and the roof structure, and tell you which conversion fits.
Plans drawn, planning or a certificate applied for, and party wall notices served.
Scaffold up, steels in, dormer or gable built, roof closed, then the inside fitted out.
Building Control completion certificate and electrical certificate handed over.
Types of loft conversion we build in London.
Rear dormer
The most common choice on terraced houses. A box dormer on the back slope gives full head height across most of the room.
Hip to gable
For semis and end of terraces with a sloping side roof. The hip is built up into a vertical gable, often combined with a rear dormer.
Mansard
A steep rear slope with a flat top, common in inner London streets. It gives the most space and almost always needs planning permission.
Rooflight conversion
Where there is already enough height, rooflights are added and the roof shape stays the same. The simplest route through planning.
Permitted development or planning permission?
Many houses can add a dormer under permitted development, within volume limits of 40 cubic metres for terraces and 50 for semis and detached homes. Flats, maisonettes and houses in conservation areas do not have those rights, and mansards usually need full planning. We check which applies before any design work is paid for.
A lawful development certificate from the council confirms that a permitted development loft is lawful. Buyers' solicitors ask for it when you sell, so we apply for it before work starts.
Building Regulations and fire safety.
Every loft conversion needs Building Regulations approval. The key item is a protected escape route: fire doors onto the stair, mains powered linked smoke alarms and a stair enclosure that runs to an exit. Insulation, ventilation and structure are inspected as the work goes along. The inspector visits at key stages, including when the steels are in and before insulation is covered, and issues a completion certificate at the end.
Structure and steelwork.
Existing ceiling joists are not designed to be a floor. New joists and steel beams are sized by a structural engineer and inspected before they are covered up. Steels are usually lifted in through the roof before the dormer is framed, with padstones spreading the load into the walls below.
The Party Wall Act.
On a terrace or semi, work to the shared wall needs a party wall notice before it starts, two months ahead for work to the wall itself. We prepare the notices so the timetable is not held up. If a neighbour dissents, a surveyor agrees a party wall award that records the condition of their property before work begins.
Stairs and head height.
Head height
Measure from the top of the ceiling joists to the underside of the ridge. Around 2.2 metres is usually enough to work with.
Where the stairs go
The new stair normally lands above the existing one. We plan it early because it decides the bedroom layout below.
Loft conversions across London.
We convert lofts in all 32 boroughs. Victorian terraces in Fulham, Hammersmith, Ealing and Wandsworth usually take a rear dormer or an L shaped conversion, while semis further out suit hip to gable lofts.
North and central London
In Camden, Kentish Town, Islington and Hampstead many streets are conservation areas, so mansards and rear dormers are designed to the council's guidance and usually go through full planning. In Golders Green and the wider north London suburbs, 1930s semis are well suited to hip to gable and dormer conversions under permitted development.
South east London
For Greenwich, Blackheath, Eltham and Dulwich see our page on loft conversions in Greenwich and south east London.
Questions we get
asked most.
Not always. Many dormers fall under permitted development, but flats, conservation areas and mansards normally need planning. We confirm it first.
Usually yes. Most of the work is done from the scaffold and the stair is opened up near the end.
On terraced and semi detached houses, usually. We prepare and serve the notices.
We do, and hand you the completion certificate at the end.
The build usually runs for several weeks depending on type and size. The fixed quote comes with a written programme.
Yes, if the drainage route works. We check the soil stack position at survey.
Yes. Camden, Kentish Town, Islington, Hampstead and Golders Green are all covered, with conservation area rules checked before design.
Send us the address
and we will check the loft.
A site visit, an honest view on which conversion fits and a fixed written quote.
Often needed
alongside this.
Areas we cover.
We take loft conversion work across all 32 London boroughs. Most of our work is in west London, in Shepherd's Bush, Hammersmith, Fulham, Kensington, Chiswick and White City, and in south west London, in Putney, Wandsworth and Wimbledon. We also work in south east London, in Greenwich, Blackheath and Lewisham.
If your property is outside these areas, call us anyway. We travel across London and will tell you honestly if a job is too far to price properly.