Single-storey extensions in Caernarfon

Covering Caernarfon

Alongside Caernarfon, we also cover Llangefni (8 miles to the north), Bangor and Pwllheli.

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 is a single-storey extension?

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.

Measured survey and design drawings
Building control application and inspections
Brickwork, roof, glazing and insulation

How much should I budget for a single-storey extension?

Guide prices for single-storey extensions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.

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

Planning and building rules in Caernarfon

Planning decisions in Wales are made by the local council, using permitted development rules set by the Welsh Government rather than England’s. Building regulations in Wales have their own approved documents, and the Party Wall etc. Act 1996 applies to work on shared walls and boundaries.

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

What should I think about before starting?

Drains under the footprint may need diverting or a build-over agreement with the water company.
Kitchens and doors have long lead times, so we order them early.

What happens after I enquire?

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

Single-storey extensions: common questions

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.

Who deals with the council for a project in Caernarfon?

We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.

Also covering

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