uPVC Dormer Windows in Gwynedd
Gwynedd homeowners come to us for upvc dormer windows that are properly detailed at the junctions — because that is where dormers succeed or fail.
uPVC Dormer Windows — indicative geometry
uPVC Dormer Windows for Gwynedd homes
Roofs across Gwynedd are dominated by Victorian and Edwardian terraces, interwar semi-detached houses and post-war bungalows, and that mix decides almost everything about what a dormer here needs to look like and how it has to be built.
Modern multi-chamber uPVC gives excellent U-values, needs no decoration and shrugs off the weather exposure a dormer takes on all four sides. Foiled finishes — anthracite grey, black, cream, woodgrain — have largely killed the old objection that uPVC only comes in white. On a rear dormer that nobody sees from the street, it is the sensible default.
Key specification
| Frame | 70mm or 80mm multi-chamber, steel reinforced |
|---|---|
| U-value | 1.2 W/m²K typical, 0.8 with triple |
| Finishes | White, foiled woodgrain, anthracite, black, cream |
| Opening styles | Casement, tilt-and-turn, top-hung, fixed |
Planning and building control in Gwynedd
If the property is in a conservation area or the dormer faces the road, a full planning application is needed. We prepare the drawings and handle the submission either way.
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 Gwynedd use us
Everything is priced from a measured survey, not a phone call — which is why our quotations tend to be the ones that still hold at the end of the job.
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 Gwynedd
FAQs
uPVC Dormer Windows in Gwynedd — FAQs
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.
Does a dormer need building regulations approval?
Yes, always — permitted development covers planning, not building control. A dormer needs approval for structure, thermal performance under Part L, fire escape and protected route under Part B, and stairs under Part K if a staircase is involved. We handle the application, the inspections and the completion certificate.
Why is my dormer leaking?
In our experience the window itself is the cause less than a fifth of the time. Far more often it is the apron flashing at the dormer front, the lead soakers where the cheeks meet the roof slope, the back gutter behind a pitched dormer, or a split at an upstand in the flat covering. Water then tracks along a rafter and appears somewhere else entirely, which is why we trace the path before quoting.
Will a dormer add value to my house?
A properly built and signed-off dormer conversion adding a bedroom and bathroom typically returns a meaningful share of its cost in value, and more in areas where floor space is scarce. The building control completion certificate is what makes the space count as habitable floor area on a valuation — without it, surveyors will not include it.
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.
Find out what your roof will take
A free measured survey in Gwynedd tells you what is achievable, what it needs, and what it costs — before you commit to anything.