Annexe extensions across Bangor, Gwynedd
A annexe extension in Bangor, Gwynedd starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in Bangor, GwyneddFrom £51,000 inc VAT
- PlanningUsually a planning application
- Build time16–24 weeks on site
- Postcode districtsLL57, LL59
What is included
- Planning application describing ancillary use
- Fire separation and alarms to building regulations
- Kitchenette, shower room and bedroom finish
- Separate or shared heating and hot water
- Design for accessibility: level thresholds, wider doors, walk-in shower
What should I budget for an annexe extension in Bangor, Gwynedd?
These guide figures apply our Wales adjustment (×0.93) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Bangor, Gwynedd: £1,860 to £3,530 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Studio annexe 25 m² | £51,000 – £64,000 | £55,500 – £70,000 | £69,500 – £88,500 |
| One-bedroom annexe 35 m² | £65,000 – £81,500 | £78,000 – £98,000 | £97,500 – £124,000 |
| Larger annexe 45 m² | £83,500 – £105,000 | £100,000 – £126,000 | £125,500 – £159,500 |
Try the guide-price tool to see a range for your own size and finish.
Planning rules that apply in Bangor, Gwynedd
In Wales an annexe linked to the house and used by your household is assessed as an extension, but its size usually means a planning application is needed.
Homes in conservation areas, national parks, National Landscapes (AONBs) and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
Covering Bangor, Gwynedd
Site visits are available across Bangor, Gwynedd (LL57, LL59). Nearby, we also take on projects in 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.
Our process, step by step
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Bangor, Gwynedd
How long does an annexe extension take to build in Bangor, Gwynedd?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 10–16 weeks design and approvals.
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.
Who do I contract with for an annexe extension in Bangor, Gwynedd?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Will an annexe affect council tax?
It can. Some annexes are assessed separately for council tax, with discounts or exemptions in some cases when occupied by a relative. Check with the Valuation Office Agency (England and Wales), your local assessor (Scotland) or Land & Property Services (Northern Ireland).
How much does an annexe extension cost?
Our guide range is about £1,860 to £3,530 per m² including VAT. A one-bedroom annexe of about 35 m² is typically £78,000 to £98,000 at standard spec in Bangor, Gwynedd.
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.