Space
Loft Conversions in London
A whole extra floor without losing a square metre of garden.
Loft Conversions in London
The cheapest square metre you will ever add to a London house is the one already sitting above your head.
A loft conversion is the one project that gives a London terrace or semi a genuine extra bedroom, a home office or a master suite without touching the garden, the party wall neighbour relationship, or in most cases the planning department. On the right roof it is also the single strongest return on investment available to a homeowner in the capital.
We survey the roof before we price it. Head height, rafter depth, the position of the water tank, the chimney breast, where the new staircase can legally land and how the existing first-floor rooms will be affected all change the answer — and all of them change the price. You will get one figure that accounts for the lot, rather than a low headline number that grows once the ceilings come down.
What you get
How we approach it
Structure handled in-house
Steel beams, new floor joists and trimming around the stairwell are designed with your engineer and installed by our own team, not sub-let to whoever is free that week.
Staircase designed first
The stair is what makes or breaks a conversion. We resolve where it lands, how much it costs the landing below, and how it meets escape regulations before anything else is drawn.
Fire and escape compliance
Protected stairwell, 30-minute fire doors, interlinked detection and, where needed, an escape window — specified properly so building control sign-off is a formality.
Live-in friendly
Access via a scaffold and roof opening wherever possible, so the majority of the mess stays outside your hallway while you carry on living in the house.
Options
Types of loft conversion
Which one suits your property is decided by the roof, not by preference. Here is what each actually gives you.
-
01Velux / rooflight conversion
Least disruptiveNo change to the roof shape — just insulation, a new floor, a staircase and rooflights set into the existing slope. The cheapest and fastest option, and almost always permitted development. Only works where you already have generous head height.
-
02Dormer conversion
Most commonA flat-roofed box built out from the rear slope to create full standing height and usable floor area. The workhorse of the London terrace, and the option that most reliably turns a loft into a proper double bedroom with an en-suite.
-
03Hip-to-gable
Biggest gain on semisThe sloping hip end of a semi or end-terrace is built up vertically into a flat gable wall, squaring off the loft. Usually combined with a rear dormer to produce the largest volume available on a typical suburban London property.
-
04Mansard conversion
Conservation areasThe rear roof is rebuilt at a near-vertical 70-degree pitch with a flat top. The most floor area of any conversion and the most sympathetic to period streets — but it is a rebuild, so it needs planning permission and a bigger budget.
-
05L-shaped dormer
Victorian terracesA dormer over the main rear roof joined to a second over the back addition, common on Victorian and Edwardian terraces. Gives two rooms plus a bathroom where a straight dormer would only give one.
Before you start
Planning, party walls and building regulations
The items below are where projects most often stall. We raise them at survey stage, not halfway through.
Permitted development
Many rear dormers fall under permitted development — up to 40 cubic metres added volume on a terrace or 50 on a semi or detached, with no part of the extension above the existing ridge and nothing forward of the front roof plane. Flats, maisonettes and most conservation areas are excluded.
Planning permission
Mansards, front-facing dormers, anything in a conservation area and anything on a listed building needs a full application. We work with your architect on the drawings and answer the technical queries the case officer raises.
Party Wall Act 1996
Cutting steels into a shared wall triggers a party wall notice to your neighbours, usually two months before work starts. We flag this at survey stage so it never becomes the thing that delays your programme.
Building regulations
Floor loading, fire escape, stair pitch and headroom, insulation and ventilation all have to be evidenced. A building control inspector visits at set stages and issues a completion certificate — which your solicitor will ask for when you sell.
Process
How your loft conversion project runs
Five stages, each with a defined output, so you always know where the job is and what happens next.
Consultation
We sit down with you and your planning representatives to turn a rough idea into a defined brief — what is possible, what it is likely to cost, and what the realistic programme looks like.
Survey
A full measured survey of the property. We check structure, services, drainage, party wall implications and access before a single figure goes on paper.
Design
We collaborate with your architect, structural engineer and consultants through drawings, building regulations and planning so the design is buildable as well as beautiful.
Build
Qualified, directly-employed craftspeople on site to an agreed programme, with a single point of contact, weekly progress updates and a clean, protected site throughout.
Completion
Snagging walked with you room by room, certificates and guarantees handed over, building control sign-off, and a site left cleaner than we found it.
Where we work
Loft Conversions across London
We deliver this service across all 33 London boroughs. Pick your area for local planning context, typical property types and recent work nearby.
Coverage mapFAQs
Loft Conversions — your questions answered
The questions we are asked most often about this service. If yours is not here, call us — we would rather answer it now than after you have committed.
A rooflight conversion is typically six to eight weeks on site. A rear dormer runs eight to twelve weeks, and a hip-to-gable with dormer or a mansard twelve to sixteen. Design, planning and party wall notices sit in front of that and are usually the longer part of the timeline.
No. The building regulation requirement applies to the finished staircase, not the whole room. What matters at survey is whether there is at least around 2.2m from the top of the existing ceiling joists to the underside of the ridge — once you have added floor build-up and insulation, that is what leaves usable standing height.
Almost all of our clients do. Access is taken through a scaffold and the roof where the property allows it, and the stairwell is only opened up in the final weeks. We seal the route and clean down daily.
In most of London an extra bedroom and bathroom in the roof adds meaningfully more than the build cost, particularly where it takes a house from two bedrooms to three or three to four. Local comparables are the honest guide — we can point you at what similar converted properties on your street have achieved.
A traditional gravity-fed tank in the loft usually has to go. Most conversions are the right moment to move to a combi or an unvented cylinder, which we price into the job rather than leaving as a surprise for your plumber.
Free quotation
Thinking about loft conversions?
Let us take a look.
Tell us what you are planning and we will arrange a free site survey and a written, itemised quotation — with no obligation and no sales visit.