We only build dormers
That sounds like a limitation. It is the reason our flashings are on the drawing rather than improvised on the scaffold.
What we are
Dormer Windows is a specialist dormer contractor working across England, Wales, Scotland and Northern Ireland. We design, build, weatherproof and sign off dormer windows, dormer loft conversions and dormer roofing — and we do not take on general building work.
Every enquiry is handled by a directly-managed team. Survey, drawings, structural calculations, planning and building regulations submissions, scaffold, structure, roofing, glazing and completion certificate all sit under one quotation and one point of contact.
How we work
Survey before price
We do not quote from photographs. A specialist comes out, gets into the loft, measures ridge height and rafter span, checks the purlins and looks at what has already been done to the property. Half of what decides a dormer's feasibility is invisible from the street.
Everything on the drawing
Flashing codes, soaker laps, back gutter formation, insulation build-up and vapour control layer continuity are all specified before you sign. That is what lets you compare our quotation with someone else's on a like-for-like basis instead of on headline price.
Weathertight before we leave
The roof is opened only once the scaffold, temporary protection and materials are on site, and it is made weathertight within the same phase. We do not open a roof on a Friday afternoon.
Signed off, not just built
Building control approval is part of the deliverable. The completion certificate is the document that makes your new floor area count on a valuation, and it is the first thing a buyer's solicitor will ask for.
Guarantees and cover
- £5m public liability insurance
- 10-year guarantee on structural work
- 20-year guarantee on GRP and EPDM flat roofing
- 10-year guarantee on window frames and sealed units
- Building control completion certificate on every conversion
Where we work
We cover 74 counties and 675 towns and cities across the UK through directly employed and vetted specialist teams. See the full coverage map →
Site notice
This website is operated as an independent lead-generation and information service for dormer window and loft conversion work. Enquiries submitted here are passed to vetted specialist installers covering your area. Details of the data controller are set out in our privacy policy.
How a dormer gets built
Seven stages, in this order, every time
The sequence matters. Most dormer problems come from doing one of these out of order — glazing before the flashings, or opening the roof before the materials land.
Survey and feasibility
A specialist measures the roof, checks ridge height, span and structure, and confirms whether you are inside permitted development.
Design and consent
Measured drawings, elevations and sections. We submit the planning application or lawful development certificate and the building regulations application.
Scaffold and protection
Scaffold designed, erected and inspected. Temporary weather protection over the work area before anything is opened.
Structure
Ridge beam and floor steels craned or manhandled in, new joists laid, the dormer frame built and sheathed.
Weatherproofing
Deck, insulation, membrane or lead, cheek cladding, flashings and gutters — the dormer is weathertight from this point.
Glazing
Windows fitted square, sealed and drained, with escape-compliant opening lights where required.
Finish and sign-off
Plaster, electrics, decoration and making good, final building control inspection and your completion certificate.
Find out what your roof will take
A free measured survey tells you what is achievable, what it needs, and what it costs — before you commit to anything.