Loft Maker London
Dormer Loft Conversions in London and Essex
A dormer pushes the roof outwards at the front or back, creating real headroom and floor area where a rooflight alone would not.
A dormer is a box that projects from a sloping roof with its own little roof and window. It is the most common loft conversion we build, and for a straightforward reason: it is the most effective way of turning a low roof into a room you can stand up in.
A rooflight alone will not do the job in most London and Essex houses. It lights the space, but it does not change the ceiling height, so the middle of the room is still unusable. A dormer changes the roof profile itself, which means headroom across the usable width, a proper window you can actually open, and a floor area that is worth the money you have spent.
Rear, front and side dormers
Rear dormers are the most common, and the easiest to justify to a planning officer, because they sit away from the street. Front dormers are possible but harder: if the principal elevation of your house fronts a highway, a dormer that extends beyond the plane of the existing roof slope is not permitted development and will need a householder planning application, judged on how it looks from the street.
Side dormers usually accompany a hip-to-gable, or sit over a side extension where the roof is already being rebuilt. If the dormer faces a neighbouring boundary, the window in it will normally need to be obscure glazed and, if it opens, set more than 1.7m above the floor. That is a permitted development condition, and it is worth designing around early rather than discovering it later.
Shape and detail
Dormers can be built with a flat roof, a shallow pitched roof, or a gabled front. The choice should follow your existing roof: a flat-roofed dormer suits a shallow modern roof, a pitched or gabled dormer suits a traditional house, and matching the tile or slate of the main roof makes the addition read as part of the building rather than an add-on.
The cheeks and the face of the dormer are where most of the visual character is decided. Materials need to be of similar appearance to the existing house under permitted development rules, and the same applies if you go for planning permission, where an officer is judging whether the addition is sympathetic.
Planning and building regulations
A rear dormer often falls inside the permitted development allowances in Class B of the GPDO: the enlargement cannot take the roof above the highest existing part of it, the volume added is capped at 40 cubic metres for a terrace and 50 for a semi-detached or detached house, and the work has to stay set back from the eaves and within the existing wall lines. A front dormer on a house fronting a highway sits outside those allowances and needs an application.
Conservation areas and Article 4 directions remove permitted development rights, so in those streets the same dormer needs a full householder application. Building regulations approval is needed either way, and the structure, fire spread and thermal performance of the new room are all checked as part of it.
What happens on site
The sequence is usually: strip the roof covering back to the existing trusses, install the steel or timber structure that carries the new walls and floor, form the dormer in place, rebuild the roof around it, then move on to the internal fit-out, glazing, plastering, electrics, heating and decoration. If the dormer sits over an existing first-floor opening, or the trusses need to be reinforced, that is planned in from the start rather than discovered on day one.
A single dormer conversion is typically six to ten weeks on site once consents are in place.
What is included
Design, planning or permitted development submission, structural engineering, building regulations, the build, roofing, glazing, plastering, first fix and second fix electrical, plumbing and heating, decorating, and the completion certificate. One team runs the whole thing, and every project carries a 10-year structural warranty.
Related services
- Loft Conversions London & Essex — Turn unused roof space into a bedroom, bathroom or home office. We handle design, consents, structure and the build.
- Side Extensions London & Essex — The side return is usually the most under-used space on a London plot. Filling it with a well-designed extension is the cheapest way to add a proper room.
Frequently asked questions
Is a dormer conversion allowed under permitted development?
Rear dormers usually are, provided the added roof volume stays within 40 cubic metres for a terrace or 50 for a semi-detached or detached house, no part rises above the existing highest roof point, and the work stays within the existing eaves and wall lines. Front dormers on a house fronting a highway need planning permission.
Do dormer windows need to be obscure glazed?
A dormer that forms part of a side elevation, or that faces a neighbouring property closely, will normally need obscure glazing under permitted development, and any opening parts must be at least 1.7m above the floor. We check the orientation and the distance to the boundary before we design the window.
Can you add a dormer to a house that already has a rear extension?
Usually yes, and it often makes sense because the extension and the conversion can be programmed together. We would normally look at converting the roof over the existing extension as well as the main roof, which gives you more usable floor area for the same scaffolding and the same scaffold tower.
How long does a dormer conversion take?
Six to ten weeks on site is typical once consents are in place, with the design and consent stage ahead of that. The full programme is on your quotation.
Do dormers need planning permission?
Often not, because dormer windows are commonly permitted development. Restrictions apply in conservation areas and listed buildings, and the window position and overall height matter. We check your specific property and apply on your behalf if permission is required.
Are dormers structurally complicated?
A dormer cuts into the roof structure, so it is not a purely cosmetic addition. The existing rafters are usually cut or doubled and the opening is framed, with flashings and a new roof section built around it. We handle the structural design and the sequencing so the weather is never left open.
What does Loft Maker London do?
We are a London and Essex construction company specialising in loft conversions, dormer and mansard roof construction, side extensions, GRP flat roofing and structural steelwork. We handle design, planning, structural engineering, groundworks, roofing and finishing in-house, so you deal with one team from first drawings to handover.
Which areas do you cover?
We work across London and Essex, including Chingford and South Woodford. We are a mobile, service-area business, so we come to you rather than asking you to visit an office.
How much does a loft conversion cost?
It depends on the property, the specification and how much of the work is structural. A straightforward conversion in an existing roof space costs less than one that needs a new structural opening, steelwork or extensive roof construction. We price every project individually and give you a clear written quote before work starts, so there is no ambiguity about what you are paying for.
Do I need planning permission for a loft conversion?
Not always, but it depends on the property and the work. Many loft conversions fall within permitted development, while mansard roofs, dormer windows in conservation areas, and work that changes the volume of a dwelling often need planning permission. Building Regulations approval is a separate requirement and applies to most structural work. We assess your specific property, tell you exactly which permissions are needed, and handle the applications.
How long does a loft conversion take?
A conversion that does not require planning permission is often built in two to three weeks on site, but the full project - surveys, designs, approvals, build and finishing - takes considerably longer. Projects involving a mansard roof, an extension or steelwork take longer again. We give you a realistic programme with the quote, and we keep you informed if anything changes.
Is my project covered by a warranty?
Every project we complete is backed by a 10-year structural warranty. The full policy wording and schedule of cover are issued to you at handover, so you know exactly what is covered and what to do if you need to make a claim.
Do you handle Party Wall notices?
Yes. Where your project affects a neighbouring property, Party Wall notices or an award may be required before work starts. We prepare the necessary paperwork, serve the notices and coordinate with the adjoining owner's surveyor where one is appointed.
Can you work from drawings we already have?
Yes. If you have planning approval, architectural drawings or structural calculations, we can price and build from them. If you would rather we took the design and planning on as well, we can do that instead - just tell us which stage you have reached.
Can you match an existing roof or extension?
Yes. We work with a range of roof tiles and finishes, and we match existing materials where we are extending or building alongside original fabric, so the finished work reads as part of the house rather than an addition to it.
What happens after I get in touch?
We arrange a free, no-obligation consultation at your property. We look at the space, discuss what you want to achieve and any constraints, and then come back to you with options and a clear written quote. There is no obligation to proceed.
Tell us about your project
Send a few details and we'll come back to you with honest advice on what is possible, what it involves and how long it takes.