An additional bedroom you already own.
A loft conversion is generally the least expensive square metre you will ever add to a London property — no foundations, no lost garden, and it typically returns more than it costs at sale. The condition is that it must be signed off correctly. That is the part we manage.
Indicative cost
Rooflight conversions from around £28,000. Dormers typically £45,000–£70,000.
The figure moves on three things: how much structure must change, whether an en-suite is included, and whether a dormer is required or the existing roofline can be worked within. We provide a realistic figure after inspecting the roof — not an attractive one that grows later.
The unglamorous parts that make it legal.
Anyone can board out an attic. What you are paying for is a room that Building Control will certify, that a surveyor will not flag at sale, and that will not become unbearable in July.
Will your loft actually work?
The figure that decides it is the head height from the top of the ceiling joists to the underside of the ridge. Roughly 2.4m gives a comfortable conversion. Below about 2.2m it becomes expensive — you are into lowering ceilings or raising the roof. We measure it on the first visit and give you a straight answer, even where that answer costs us the project.
Six to eight weeks, and you remain in the property.
Most of the work happens above your ceiling. It is noisier than you would like, but considerably less disruptive than an extension.
Feasibility visit
We measure the head height, assess the roof structure and identify where the staircase can land. You will know within twenty minutes whether it is viable.
Drawings & approvals
Architectural drawings, structural calculations, Building Control application and any party wall notices. This stage runs 4–8 weeks — begin it early.
Structure & shell
Steels installed, floor strengthened, dormer built or rooflights fitted, roof made watertight. This is the loud fortnight.
Fit-out & sign-off
Insulation, staircase, plastering, electrics, en-suite and decoration. Building Control carries out its final inspection.
The questions people don't ask out loud.
So we'll answer them here instead.
Do we need planning permission?
Usually not. Most loft conversions fall within permitted development, meaning no planning application is required. Building Regulations approval is a separate matter and is always required. Conservation areas and flats are governed differently — we will confirm on the first visit.
Will we need to move out?
Almost never. The bulk of the work takes place above your ceiling. The two genuinely disruptive moments are when the roof is opened and when the staircase is installed. You will be given notice before each.
What if our head height is insufficient?
Then we will tell you, and we would rather tell you before you have spent anything. Below approximately 2.2m you are looking at lowering the ceilings below or raising the roof — both possible, both costly. Some contractors take a deposit and discover this later. We check first.
“They talked us out of a dormer. We had assumed one was necessary; they measured the ridge and advised that a rear rooflight conversion would give us the room we wanted for roughly eighteen thousand pounds less. Most contractors would have taken the larger project.”
James O. · Loft conversion, Ealing
Loft Conversions — straight answers.
A rooflight conversion typically starts around £28,000. A rear dormer, which delivers considerably more usable floor area, usually runs £45,000–£70,000 depending on size, with an en-suite pushing toward the upper end. An exact figure follows the feasibility visit.
Most do not — they fall within permitted development rights. Building Regulations approval is always required, however, covering structure, fire escape and insulation. Conservation areas, listed buildings and flats are governed differently, and we will confirm your position before you spend anything.
Major lenders have consistently placed it around 15–20% of a property's value for an additional bedroom with an en-suite, which across most of London comfortably exceeds the build cost. That is a general guide rather than a guarantee — a local estate agent can advise on your specific street.
Six to eight weeks on site for most conversions. The approvals stage beforehand takes a further 4–8 weeks, so allow roughly three to four months from first enquiry to completed room. Begin the paperwork early.
Roughly 2.4m from the top of the existing ceiling joists to the underside of the ridge gives a comfortable conversion. It remains possible below that, though costs rise. We measure it during the free feasibility visit and give a straight answer.
Find out what your loft is worth.
A free feasibility visit and an honest answer on head height, cost, and whether the project is worth undertaking at all.