Double-storey extensions in Amersham

Covering Amersham

Amersham sits 27 miles south of Milton Keynes, with Beaconsfield 4 miles to the south and High Wycombe 6 miles to the south-west.

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 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
Foundations, steelwork, brick and block walls, roof

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

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

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

In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it 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. Expect around eight weeks for a decision once the application is validated.

What should I think about before starting?

Neighbours’ light is assessed using the 45-degree guide many councils use.
The new roof is tied into the old one, so roof tiles and ridge details need to match.

What are the steps?

Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
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.
We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

What people ask before starting

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 Amersham?

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

Double-storey extensions in nearby towns

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