Double-storey extensions · Egham

Double-storey extensions in Egham

Planning double-storey extensions in Egham? We design and build them for houses across Surrey, and we fix the price for the agreed specification in writing before any building work starts.

Covering Egham

Egham is about 14 miles north of Guildford. We also cover Staines (2 miles to the east), Ashford and Windsor.

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 Egham?

A double-storey extension adds new rooms on both the ground and first floor in one build, typically a larger kitchen or living space downstairs and an extra bedroom or bathroom above. Because the roof and foundations are shared, the cost per square metre is usually lower than a single-storey extension.

  • Measured survey, design and planning drawings
  • Foundations, steelwork, brick and block walls, roof
  • Windows, insulation, plastering, electrics and plumbing

What will a double-storey extension cost?

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 extensionsGuide 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 Egham?

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. Expect around eight weeks for a decision once the application is validated.

What can affect a double-storey extension?

  • The new roof is tied into the old one, so roof tiles and ridge details need to match.
  • The first-floor link can mean moving a bathroom or reshaping the landing.

What are the steps?

  1. Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
  2. We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
  3. Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
  4. We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

What people ask before starting

How much does a two-storey extension cost?

Typically about £2,400 to £3,850 per square metre of new floor area including VAT. A 40 m² extension across two floors is often around £100,000 to £150,000 depending on specification.

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.

Do you work in Egham?

Yes. Egham is within our coverage for double-storey extensions, along with nearby Staines and Ashford.

Double-storey extensions in nearby towns

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

Planning an extension, loft or new home?

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