Dormer windows in Swindon
If you are weighing up dormer windows and dormer loft conversions in Swindon, we survey the roof, tell you what is actually achievable, and price it properly before anyone commits.
What we build in Swindon
Swindon is a mix of Victorian and Edwardian terraces, interwar semi-detached houses and post-war bungalows, and each of those wants a different dormer form — which is why we survey before quoting rather than pricing off a photograph.
Whether that is a single flat roof dormer to make a back bedroom usable, or a full-width rear dormer with a bedroom and en-suite, the process is the same: a free measured survey first, a fixed written price second, and nothing else until you have both in front of you.
Planning permission in Swindon
Rear dormers on houses often sit inside permitted development, but the volume allowance is consumed by any previous loft or rear extension — so we check the planning history for the address before we say yes.
Swindon sits in Wiltshire, and local authority interpretation of the volume allowance does vary — which is why we check the planning history at your specific address rather than assuming the neighbours' dormer sets a precedent.
How the job runs
Glazing
Windows fitted square, sealed and drained, with escape-compliant opening lights where required.
Survey and feasibility
A specialist measures the roof, checks ridge height, span and structure, and confirms whether you are inside permitted development.
Scaffold and protection
Scaffold designed, erected and inspected. Temporary weather protection over the work area before anything is opened.
Weatherproofing
Deck, insulation, membrane or lead, cheek cladding, flashings and gutters — the dormer is weathertight from this point.
One quotation covers scaffold, structure, weatherproofing, glazing, plastering and sign-off. You are not coordinating four trades who each blame the last one. Book the survey, get the fixed written price, and decide in your own time. Nothing about that process commits you to anything.
Popular in Swindon
Dormer work we are asked for most
Hipped Roof Dormers
Three sloping faces instead of a gable — softer, and often easier to get past planning.
Learn moreBox Dormers
A simple squared projection — the workhorse dormer for bedrooms and bathrooms.
Learn moreBungalow Dormer Conversions
Turn a bungalow's roof void into a first floor — often doubling the footprint.
Learn moreuPVC Dormer Windows
Low maintenance, well insulated and the most cost-effective frame for a dormer.
Learn moreConservation Dormer Windows
Heritage-profile dormers and glazing for conservation areas and listed buildings.
Learn moreDormer Window Repairs
Leaks, rot, failed flashings, blown units and draughts — diagnosed and put right.
Learn moreFAQs
Dormers in Swindon — FAQs
Will my roof be open to the weather?
No. The roof is only opened once the scaffold, temporary weather protection and materials are all on site, and the dormer is made weathertight — structure, deck, membrane and temporary glazing — before the crew leaves at the end of the opening-up phase. We do not open a roof on a Friday afternoon.
Can you build a dormer on a bungalow?
Usually yes, and bungalows often give the best results because the spans are wide and there are no party walls. The deciding factor is ridge height: you generally want at least 2.6m from the top of the ceiling joists to the underside of the ridge. We measure this at survey before committing to anything.
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.
What insulation do dormers need?
Current building regulations want around 0.15–0.18 W/m²K for a new dormer roof and 0.18 W/m²K for the cheeks and front. In practice that is a warm-roof build-up using 100–150mm of PIR insulation above or between the structure, with a continuous vapour control layer on the warm side. Getting the VCL continuous matters more than the insulation thickness.
Do you handle the planning application?
Yes. We prepare measured drawings, elevations and sections, submit the application or the lawful development certificate, and deal with the case officer's queries. On conservation and listed work we also put together the heritage justification the application needs.
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 Swindon tells you what is achievable, what it needs, and what it costs — before you commit to anything.