Dormer loft conversions in Nottingham
A dormer loft conversion builds a box-shaped extension out from the rear slope of your roof, with vertical walls, a window and a flat roof. It turns cramped sloping ceilings into floor space you can stand up in, which is why it suits lofts that are too tight for rooflights alone.
We design and build rear dormers, full-width dormers and L-shaped dormers for Nottingham houses, including layouts with an en-suite, and manage the approvals, structure and fit-out.
- More full-height floor area than a rooflight conversion
- Rear dormers may fall under permitted development, subject to checks
- A written, itemised quotation after a free survey
How a dormer creates headroom
In an unconverted loft, the only full-height space is a narrow strip under the ridge. A dormer pushes the rear roof slope outwards and upwards into a vertical wall, so the height under the ridge carries on across most of the dormer’s footprint.
That extra standing room is what makes the loft usable. It gives space for a bed you can walk around, a desk you can sit at without ducking, and a staircase that arrives with proper headroom. The new staircase usually lands under the dormer for exactly this reason.
Because the dormer sits on the rear slope, the front of the house normally keeps its original roofline. Rooflights can be added to the front slope for extra daylight.
Best for
Houses where the existing loft is too low or too narrow for a rooflight conversion. A good fit for a main bedroom with en-suite, a large home office, or a bedroom and study.
Quick facts
A typical dormer takes around 6 to 8 weeks on site as an indicative guide, after design and approvals. Rear dormers on houses may fall under permitted development, depending on the property.
Which dormer suits your house
The width and shape of the dormer depend on your roof, the planning position and how many rooms you want up there.
Single rear dormer
A dormer across part of the rear slope, often enough for one extra bedroom. Leaving roof on either side keeps the volume down and can help with party wall matters.
Full-width rear dormer
Runs across the whole rear slope, usually from party wall to party wall on a terrace or semi. It gives the most floor area from the main roof and can fit two rooms or a bedroom with a shower room.
L-shaped dormer
Joins a dormer on the main roof with a second one over the rear outrigger. It suits Victorian and Edwardian terraces with a back addition and can create two good-sized rooms.
Fitting an en-suite into a dormer
A shower room needs standing height at the shower and in front of the basin and WC. The vertical dormer wall gives that height where a sloping roof would not, which is why many dormer layouts put the en-suite against the dormer face.
The main practical question is drainage. The waste from a WC has to reach the existing soil stack with enough fall, so a loft bathroom positioned above or near the bathroom below is usually simpler. Where that is not possible, the layout or the drainage route needs more planning, and we look at this at the survey.
Water pressure, extraction to the outside and the loss of floor area to a stud wall also need thinking about before the layout is fixed.
Worth deciding early
Deciding on an en-suite early matters, because it affects the dormer width, window positions and staircase arrival point. Changing it later can mean redrawing the plans.
Why homeowners choose a dormer
- Standing room across the floor. The vertical wall gives full height over much more of the room than sloping ceilings allow.
- Normal windows. The dormer face takes a standard window, which is easier to open, clean and fit blinds to than a roof window.
- Space for a bathroom. The extra height makes a shower room with a WC far more workable.
- Front elevation unchanged. A rear dormer keeps the street view of the house largely as it is.
- Works on many house types. Terraces, semis and detached houses with a pitched rear roof slope.
How a dormer conversion is built
Free survey
We measure the loft, check the head height, roof pitch and structure, and look at where the stairs and any en-suite could go.
Design and quote
Drawings set the dormer size, windows and layout. You receive a written, itemised quotation for the agreed specification.
Approvals
We coordinate the permitted development or planning position, Building Regulations and any party wall notices.
Structure
Scaffold goes up, steels and new floor joists go in, the dormer walls and flat roof are framed and the roof is made watertight.
Fit-out
Staircase, insulation, windows, fire doors, wiring, plumbing and plastering are completed.
Finish and sign-off
Decoration and clean-up, then the final building control inspection and completion certificate.
Dormer loft conversion costs
| Type | Indicative guide price (2026) | Typical use |
|---|---|---|
| Single rear dormer | £40,000 to £55,000 | One extra bedroom |
| Dormer with en-suite | £50,000 to £65,000 | Main bedroom suite |
| Full-width rear dormer | £55,000 to £75,000 | Two rooms or a large suite |
| L-shaped dormer | £65,000 to £90,000 | Victorian terraces with an outrigger |
These are indicative guide ranges, not quotes. The dormer width, the amount of steelwork, the external finish, window choices, an en-suite, scaffold access and party wall costs all affect the price. We confirm it in a written, itemised quotation after the free survey.
Planning rules for dormers
A rear dormer on a house may fall under permitted development (Class B), depending on the property and any restrictions. The dormer’s volume counts towards the allowance of 40 cubic metres for terraced houses and 50 cubic metres for semi-detached and detached houses, along with any earlier roof additions.
For a dormer to qualify, it generally needs to stay below the existing ridge, sit on a slope that does not face the road at the front, use materials similar in appearance to the existing house, and be set back roughly 20cm from the eaves where practicable. Any side-facing window must be obscure-glazed and non-opening unless the opening part is more than 1.7m above the floor. Balconies are not allowed.
Front dormers, flats and maisonettes, and houses in conservation areas or with removed permitted development rights need a planning application. Your property needs to be checked, and many homeowners apply for a Lawful Development Certificate to confirm the position.
Building Regulations approval is needed either way. On terraced and semi-detached houses, a dormer often involves steels bearing on the party wall, so the Party Wall etc. Act 1996 is likely to apply.
Dormer planning checklist
- Rear slope, not the front slope facing a road
- Within 40m³ (terraced) or 50m³ (semi or detached)
- No higher than the existing ridge
- Set back about 20cm from the eaves where practicable
- Materials similar in appearance to the house
- Side windows obscure-glazed and fixed below 1.7m
- Party wall notice likely on terraces and semis
See the work before you decide
Look at finished projects and speak to past customers before you commit to a dormer.
Browse finished projects
Our gallery shows completed extensions and conversions so you can judge the finish yourself.
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Read our customer reviewsAsk for a reference
At the survey, ask to speak to a past customer who had a similar loft project.
Book your free surveyDormer loft conversion questions
Our indicative guide ranges run from £40,000 to £55,000 for a single rear dormer up to £65,000 to £90,000 for an L-shaped dormer. Size, finishes and an en-suite make the biggest difference. We give a written, itemised quotation after the free survey.
A rear dormer on a house may fall under permitted development if it meets the Class B conditions and volume limits. Front dormers, flats, conservation areas and homes with removed permitted development rights need an application. We check your property at the survey.
As an indicative guide, a typical dormer takes around 6 to 8 weeks on site, and L-shaped dormers can take longer. Design, approvals and any party wall notice period come before that. We give you a programme once the design is agreed.
Often, yes. The dormer gives the standing height a shower and WC need. The main check is whether the waste can reach the existing soil stack with enough fall, which is easier when the loft bathroom sits above or near the one below.
A rooflight conversion keeps the roof shape and adds windows in the slope, so headroom stays limited to the centre of the loft. A dormer alters the roof to create full standing height over a larger floor area.
Under permitted development, the materials should be similar in appearance to the existing house. That usually means tiles, slates or cladding chosen to sit well with the main roof. If a planning application is needed, the council will also look at the design.
In most cases, yes. The dormer is built from the scaffold and inside the roof. The most disruptive stage is when the staircase opening is cut and the new stair is fitted.
Dormer conversions across the area
Not sure if we cover your street? Get in touch and we will let you know.
Find out how big your dormer could be
Request a free survey. We will measure the loft, check the roof and the planning position, and show you how much full-height floor space a dormer could give you.