Extensions over a garage in Caernarfon
Our extensions over a garage service in Caernarfon covers everything: measured survey, design, planning or permitted development checks, structural design, building control and the build itself.
Useful details for planning an extension over a garage in Caernarfon.
- Postcode districts
- LL54, LL55 and LL61
- County / area
- Gwynedd and Anglesey, Wales
- Price region
- Wales
- Guide price
- £29,000–£42,000 (£1,610–£2,350 per m²)
- Approval route
- Can be permitted development in Wales if it is 10.5 m from the side boundary, set back 1 m from the front and doesn't widen the house by more than half; otherwise planning permission.
- Nearest towns
- Menai Bridge (7.3 miles), Llangefni (8.1 miles), Bangor (Gwynedd and Anglesey) (8.3 miles)
- Distance to Bangor (Gwynedd and Anglesey)
- about 8.3 miles
- First visit
- Free, no obligation
About an extension over a garage
An extension over a garage is a new first-floor room built on top of an existing attached garage, usually a bedroom, en-suite or study. It uses a footprint you already have, so it adds floor space without taking any garden. The garage walls and foundations often need strengthening or replacing to carry the new floor.
We cover postcode districts LL54, LL55 and LL61 in and around Caernarfon, along with neighbouring Menai Bridge, Llangefni and Bangor (Gwynedd and Anglesey).
What it costs in Caernarfon
Most of the cost of an extension over a garage is set by its size and specification. For Caernarfon and the rest of Wales, our guide is £1,610–£2,350 per m² including VAT, so about £29,000–£42,000 for 3 m × 6 m of new first-floor space (18 m²). These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.
| Spec | Per m² | 3 m × 6 m of new first-floor space (18 m²) |
|---|---|---|
| Essential | £1,480–£2,160 per m² | £26,500–£39,000 |
| Standard | £1,610–£2,350 per m² | £29,000–£42,000 |
| Premium | £1,930–£2,820 per m² | £35,000–£50,500 |
Planning and building regulations in Caernarfon
In Wales, building over a side garage can be permitted development if the result is at least 10.5 m from the boundary opposite the side wall, set back at least 1 m from the front of the house and does not widen the house by more than 50%. Garages close to the boundary usually fail these tests, so a householder application costing £585 is often needed.
Approval in Wales: Householder planning application: £585. Councils normally decide householder applications within 8 weeks.
Building regulations: Building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency).
Design points for Caernarfon homes
Garage walls and the door opening
Garage walls are often a single skin of brick or block with piers, and the wide door opening needs a beam over it. Many over-garage extensions need new inner walls or a steel frame to carry the floor and to insulate properly, which we confirm before the design is fixed.
Checking the garage foundations
Garages are often built on shallow strip footings sized for a single-storey wall and a light roof. A trial hole shows their depth and condition, and the engineer decides whether they can carry two storeys or need underpinning or new foundations inside the garage.
How we'd run your project
Free site visit
We visit your home in Caernarfon, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Drawings, then consent
We draw the scheme, check it against the rules in Wales, and take it through the right consent with the council.
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.
Questions about extensions over a garage in Caernarfon
Who handles building regulations for a project in Caernarfon?
We handle it as part of the project. What's needed in Wales: building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency). We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.
How long does an extension over a garage take?
Allow 4 to 8 weeks for survey and design, then the approval period (councils normally decide householder applications within 8 weeks), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.
How much does an extension over a garage cost in Caernarfon?
Our guide for Wales, which covers Caernarfon, is £1,610–£2,350 per m² including VAT. A typical project with 3 m × 6 m of new first-floor space (18 m²) comes to about £29,000–£42,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
How do I get into a room over the garage?
Usually through a new opening off the existing landing or a bedroom, so the stairs stay where they are. If the floor levels do not match, a step or two may be needed inside the new room. Where a landing opening is not practical, a new stair from a converted garage is an option.
Can I add an en-suite above the garage?
Yes, and it is a common choice for a main bedroom. The en-suite needs an extract fan under Part F, a route for the soil pipe down to the drains and enough fall for the waste, which can be harder over a garage. We plan the pipe route through the garage or an outside wall early.
Nearby
Other towns near Caernarfon:
Other extensions in Caernarfon
- Rear
- Side
- Wraparound
- Part two-storey
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Caernarfon · Extensions over a garage across Gwynedd and Anglesey
Book a free site visit in Caernarfon and we'll tell you what's possible, what approvals you need and what the design stage would cost.