Aluminium Dormer Windows in West Sussex
West Sussex homeowners come to us for aluminium dormer windows that are properly detailed at the junctions — because that is where dormers succeed or fail.
Aluminium Dormer Windows — indicative geometry
Aluminium Dormer Windows for West Sussex homes
Because West Sussex is largely Victorian and Edwardian terraces, interwar semi-detached houses and post-war bungalows, the roof pitches and span widths we meet are fairly predictable, and that makes feasibility a quick conversation rather than a guess.
A dormer usually has one window and one aspect, so every millimetre of frame you remove is daylight you gain. Thermally broken aluminium gives sightlines around 40% slimmer than uPVC for the same structural span, in any RAL colour, with a service life measured in decades. It is the premium choice on a contemporary flat roof dormer.
Key specification
| System | Polyamide thermally broken |
|---|---|
| Sightlines | Approx. 40% slimmer than uPVC |
| Finish | Any RAL, polyester powder coated |
| U-value | 1.4 W/m²K typical, 1.0 with triple |
Planning and building control in West Sussex
Getting the consent route right at the start saves months. We establish whether it is permitted development, a lawful development certificate or a full application on the first visit.
Building regulations approval is separate and always required. We submit the application, book the inspections around the programme and hand you the completion certificate at the end — the document a buyer's surveyor will ask to see.
Why homeowners in West Sussex use us
The completion certificate is part of the deliverable, not an afterthought. It is the document that makes the space count when you come to sell.
Book the survey, get the fixed written price, and decide in your own time. Nothing about that process commits you to anything.
Other dormer work in West Sussex
FAQs
Aluminium Dormer Windows in West Sussex — FAQs
Is scaffolding included in the price?
Yes. Every quotation we issue includes scaffold design, erection, weekly inspection, hire for the programme and dismantling. Scaffold appearing as an extra afterwards is one of the more common complaints about dormer work, so we price it in from the start.
How wide can a dormer be?
Structurally, as wide as the roof — full-width rear dormers regularly run six to eight metres, carried on a steel ridge beam. The limits are usually planning volume allowances and the setbacks needed at eaves and ridge, rather than what can be built.
What guarantees do you provide?
Structural work carries a ten-year guarantee, GRP and EPDM flat roofing twenty years, windows ten years on frames and sealed units, and lead and zinc work is covered for workmanship for ten years. You also receive the building control completion certificate, which is the document that actually matters when you sell.
Can you build a dormer in winter?
Yes, with adjustments. Temporary weather protection over the scaffold lets structural work continue in most conditions. GRP roofing needs dry conditions above about 5°C to cure properly, so in a cold spell we either sequence it differently or specify EPDM, which is unaffected.
How much does a dormer window cost?
A single flat roof dormer typically runs from around £9,000 to £20,000 supplied and fitted, depending on width, cladding finish and access. A full-width rear dormer on a semi is usually £28,000 to £45,000, and a complete dormer loft conversion including stairs, insulation, plaster and building control sign-off is more commonly £40,000 to £70,000. Our online guide-price tool gives you an indicative range in about a minute.
Find out what your roof will take
A free measured survey in West Sussex tells you what is achievable, what it needs, and what it costs — before you commit to anything.