Bangor, Gwynedd flat roof extensions, designed and built
Bangor, Gwynedd homeowners can use us for the whole flat roof extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in Bangor, GwyneddFrom £19,500 inc VAT
- PlanningWelsh permitted development rules (rear up to 4 m)
- Build time10–16 weeks on site
- Postcode districtsLL57, LL59
Do I need planning permission in Bangor, Gwynedd?
In Wales a single-storey rear extension can usually project up to 4 m beyond the rear wall without a planning application, if it is no more than 4 m high, keeps eaves to 3 m and overall height to 4 m within 2 m of a boundary, and covers no more than half the land around the original house. Wales has no larger home extension prior approval scheme.
In a conservation area, national park, National Landscape or World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. Wales has its own building regulations and approved documents; the council or a registered building control approver checks the plans, inspects the work and issues a completion certificate.
Building over or within 3 m of a public sewer needs the water company's consent before the foundations go in.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
Guide prices for Bangor, Gwynedd
Prices below are for Bangor, Gwynedd, using the Wales factor of ×0.93. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Bangor, Gwynedd: £1,630 to £3,120 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £19,500 – £23,000 | £22,500 – £29,500 | £29,000 – £37,500 |
| 4 m × 5 m 20 m² | £32,500 – £38,500 | £38,000 – £48,500 | £48,000 – £62,500 |
| 5 m × 6 m 30 m² | £48,500 – £57,500 | £57,000 – £73,000 | £72,500 – £93,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Covering Bangor, Gwynedd
Across LL57, LL59, we can visit, measure and advise. Neighbouring towns we cover include Caernarfon (7 miles), Llangefni (8 miles), Holyhead (19 miles).
For homes towards Clwyd, Llandudno is around 14 miles away. In Wales, terraced houses with rear offshoots are common in the towns, while detached houses and bungalows dominate in rural areas.
What is included
- Membrane choice: single-ply, EPDM or GRP
- Parapets or edge trims and flashings to the house
- Warm-roof design with insulation above the deck
- Lanterns or rooflights with upstands
- Falls and outlets designed to drain properly
What happens next
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Bangor, Gwynedd home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Your questions about a flat roof extension in Bangor, Gwynedd
Do you cover all of Bangor, Gwynedd?
Yes, across the whole of Bangor, Gwynedd. Site visits are free and there is no obligation.
Do I need building regulations approval in Bangor, Gwynedd?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
How long does a flat roof extension take to build in Bangor, Gwynedd?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Are flat roof extensions cheaper?
Usually slightly, because there is less roof structure and no tiles. Our guide range is about £1,630 to £3,120 per m² including VAT.
Can I walk on a flat roof extension?
Only for maintenance unless it is designed as a terrace. A roof terrace or balcony needs planning permission and a different structure.
Book a free site visit in Bangor, Gwynedd
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.