Single-storey extensions in Truro

Covering Truro

Alongside Truro, we also cover Falmouth (8 miles to the south), Redruth and St Austell.

Because Cornwall covers a wide area, we confirm availability after the first call and include any travel costs in the written quote rather than adding them later.

Homes in the South West

Homes in the South West range from coastal and rural properties in stone and slate to city terraces and modern estates, so extensions are designed to match the local materials.

What goes into a single-storey extension?

We design the extension around how you use the house: where the light comes from, how the new room joins the old one, and what happens to the drains and the garden. The structure is built in brick or block to match the house, finished with a flat roof and lantern or a pitched roof, then insulated, plastered and handed back ready to decorate.

Building control application and inspections
Foundations, drainage and structural steel
Brickwork, roof, glazing and insulation

What will a single-storey extension cost?

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

How is a single-storey extension approved in Truro?

Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.

In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary. Deeper extensions, up to 6 m or 8 m, need prior approval from the council first.

What can affect a single-storey extension?

Building on or near a shared boundary usually means serving a party wall notice in England and Wales.
Kitchens and doors have long lead times, so we order them early.

What are the steps?

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
Construction and completion. One site lead co-ordinates every trade through to the building control certificate.

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.

Do you need to dig up the drains?

Sometimes. If a public sewer runs under the extension, the water company has to agree a build-over or a diversion. We check this at survey stage.

Who deals with the council for a project in Truro?

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 Truro.