Double-storey extensions in Horley

Covering Horley

Our coverage around Horley (RH6) also includes Crawley, Redhill and Reigate.

Homes in the South East

The South East has a lot of 1930s and post-war semi-detached housing, well suited to rear extensions and hip-to-gable loft conversions, alongside period properties in conservation areas that need a more careful design.

What is included in a double-storey extension in Horley?

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.

Measured survey, design and planning drawings
Householder planning application
Structural engineer’s design and calculations

How much does a double-storey extension cost in Horley?

Typical ranges for double-storey extensions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.

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

What approvals does a double-storey extension need in England?

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.

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.

What should I think about before starting?

Side extensions close to a boundary are often set back or stepped down so they do not create a terraced effect.
The first-floor link can mean moving a bathroom or reshaping the landing.

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.
We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
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.

Questions about a double-storey extension in Horley

Is a two-storey extension better value than a single-storey one?

Per square metre, usually yes, because the foundations and roof serve two floors of space.

How long does a two-storey extension take?

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

Who deals with the council for a project in Horley?

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

Also covering

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