Single-storey extensions in Gwynedd and Anglesey

Covering Gwynedd and Anglesey

Our coverage across Gwynedd and Anglesey includes Bangor, Holyhead, Caernarfon and Llangefni.

Homes in Gwynedd and Anglesey

Across Wales you find valley terraces, coastal towns, rural stone houses and newer estates, so access, slopes and local materials all feature in the design.

What does a single-storey extension involve?

A single-storey extension adds one level of new floor space to the back or side of a house, usually to open up a kitchen, dining or family room. It is the most common way to gain space without moving, and many can be built without a planning application.

Building control application and inspections
Brickwork, roof, glazing and insulation
First-fix and second-fix electrics, plastering and making good

What is the guide price for a single-storey extension in Gwynedd and Anglesey?

Use these ranges to budget for single-storey extensions; the survey turns them into a fixed price for the agreed specification.

Single-storey extensions	Guide price incl. VAT
Standard specification	£2,600 to £3,000 per m²
Good specification	£3,000 to £3,500 per m²
High specification	£3,500 to £4,000 per m²

How is a single-storey extension approved in Gwynedd and Anglesey?

Welsh projects need planning clearance from the council under Welsh rules, building regulations approval under the Welsh approved documents, and party wall notices where the work affects a neighbour’s wall or foundations.

Wales has its own permitted development rules, set by the Welsh Government.

What can change the price or programme?

Drains under the footprint may need diverting or a build-over agreement with the water company.
Large glazed areas need to meet energy rules, which can shape the size of doors and rooflights.

What happens after I enquire?

Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Your questions answered

How much does a single-storey extension cost?

Most single-storey extensions cost about £2,600 to £4,000 per square metre including VAT, depending on specification, glazing and ground conditions. We give a fixed price in writing for the agreed specification after the survey.

Can we stay in the house during the build?

Usually yes. We keep the existing house closed off from the works until the knock-through near the end, and agree a temporary kitchen set-up with you if the kitchen is affected.

Do you work in Gwynedd and Anglesey?

Yes. Gwynedd and Anglesey is within our coverage for single-storey extensions, along with nearby Bangor and Holyhead.

Single-storey extensions in nearby towns

Learn more about single-storey extensions, or see every project we cover in Gwynedd and Anglesey.