Building regulations for extensions across Gwynedd
We prepare building regulations for extensions for homes across Gwynedd, on their own or as the first stage of a full design and build project.
- Guide priceFrom £800 inc VAT
- Approval routeFull plans or building notice
- Towns covered4
- Site visitFree, no obligation
Towns in Gwynedd
Fees in Gwynedd
Guide fees for Gwynedd including VAT, using our Wales factor of ×0.93. Council and building control charges are not included.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Building regulations drawings for a simple single-storey extension | £800 – £1,700 |
| Standard | Drawings plus structural calculations | £1,200 – £2,450 |
| Premium | Complex or two-storey pack with energy calculations | £2,000 – £3,550 |
Our design fee only. Building control charges are set by your council (or, in England and Wales, a registered building control approver) and quoted separately.Council fees are extra and are set by the Welsh Government.
For a figure based on your own dimensions, use our guide-price tool.
Who this service is for
- Every extension, whatever the planning route
- Glass-heavy designs that need energy calculations
- Homeowners using their own builder who need the drawings
Building regulations approval and planning permission are separate. A design can have planning consent and still need changes to meet the regulations, which is why we draw for both together.
Planning and approvals in Gwynedd
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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.
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).
Working in Gwynedd
Towns we cover in Gwynedd include Bangor, Gwynedd, Caernarfon, Holyhead, Llangefni. In Wales, terraced houses with rear offshoots are common in the towns, while detached houses and bungalows dominate in rural areas.
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 Gwynedd home, measure up, talk through what you want and check the planning position.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Gwynedd
Do you cover all of Gwynedd?
Yes, across the whole of Gwynedd. Site visits are free and there is no obligation.
Do I need building regulations approval in Gwynedd?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for 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.
Who are building control?
Either your local council’s building control team or a registered building control approver. Both inspect the work and issue the completion certificate.
Full plans or building notice?
A full plans application gets the drawings checked before work starts, which we usually recommend for extensions. A building notice is quicker to submit but carries more risk if something needs changing on site.
Book a free site visit in 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.