Extensions over a garage in Bangor, Gwynedd: design, approvals and build
If you live in Bangor, Gwynedd and want more space without moving, an over-garage extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in Bangor, GwyneddFrom £22,000 inc VAT
- PlanningAn application to the council is needed
- Build time12–18 weeks on site
- Postcode districtsLL57, LL59

Covering Bangor, Gwynedd
Site visits are available across Bangor, Gwynedd (LL57, LL59). Neighbouring towns we cover include Caernarfon (7 miles), Llangefni (8 miles), Holyhead (19 miles).
Welsh housing ranges from stone terraces in the valleys to render-and-slate houses and modern estates, and the Welsh planning rules differ from England's in several places.
What is included
- Design and householder planning application
- Opening into the existing first floor
- Insulation, electrics, heating and finish
- Strengthening or rebuilding the garage walls if needed
How much does an over-garage extension cost in 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: £1,670 to £3,160 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £22,000 – £27,500 | £23,000 – £30,500 | £30,000 – £38,000 |
| Over a large single garage 16 m² | £26,500 – £33,000 | £31,000 – £40,500 | £40,000 – £51,000 |
| Over a double garage 24 m² | £40,000 – £49,500 | £46,500 – £60,500 | £60,000 – £76,000 |
For a figure based on your own dimensions, use our guide-price tool.
Will the council need to approve it?
In Wales a two-storey side extension must be at least 10.5 m from the side boundary to be permitted development, which few houses can meet, so a planning application to the council is the usual route for a room over a garage.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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.
The Party Wall etc. Act 1996 applies in Wales as in England: notice must be served before work to a shared wall, building on the boundary, or excavating close to a neighbour's foundations.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions people ask about over-garage extensions
Will my neighbours in Bangor, Gwynedd be involved?
If a planning application is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Bangor, Gwynedd, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How long does an over-garage extension take to build in Bangor, Gwynedd?
On site, typically 12 to 18 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
How much does a room over a garage cost?
Our guide range is about £1,670 to £3,160 per m² including VAT. A single-garage room of about 12 m² usually costs £23,000 to £30,500 at standard spec, more if the garage needs rebuilding.
Can I keep using the garage during the build?
Usually not for parking. The garage roof is removed and the space below is used for access and props for part of the build.
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.