Double-storey extensions in St Austell

Covering St Austell

Our coverage around St Austell (PL25) also includes Bodmin, Truro and Falmouth.

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 double-storey extension?

Two-storey work has to sit comfortably with the house and the neighbours, so most of the design effort goes into the roofline, window positions and how the new first floor connects to the landing. We handle the planning application, the structural design and the building control process, then build, roof and finish both floors.

Householder planning application
Structural engineer’s design and calculations
Windows, insulation, plastering, electrics and plumbing

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

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

Double-storey extensions	Guide price incl. VAT
Standard specification	£2,400 to £2,900 per m²
Good specification	£2,900 to £3,400 per m²
High specification	£3,400 to £3,850 per m²

How is a double-storey extension approved in St Austell?

English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.

Two-storey rear extensions can sometimes be permitted development in England (no more than 3 m deep, at least 7 m from the rear boundary, roof pitch to match), but most two-storey and all two-storey side extensions need householder planning permission. Expect around eight weeks for a decision once the application is validated.

What should St Austell homeowners check first?

Side extensions close to a boundary are often set back or stepped down so they do not create a terraced effect.
Neighbours’ light is assessed using the 45-degree guide many councils use.

From first call to completion

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.
Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

What people ask before starting

How long does a two-storey extension take?

Around 14 to 24 weeks on site, plus the planning period before that.

Will we need to move out?

Most people stay. The noisiest stage is when we break through into the existing first floor, which we plan for a short window.

How do I get a price for double-storey extensions in St Austell?

Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.

Double-storey extensions near St Austell

Learn more about double-storey extensions, or see every project we cover in St Austell.