Garden annexes · Horsham

Garden annexes in Horsham

Garden annexes for homes in Horsham and the surrounding parts of West Sussex, designed around your house and built by our teams under a single written contract.

Covering Horsham

We work in Horsham (RH12) and the places around it, including Crawley, Horley and Haywards Heath.

Homes in the South East

Many South East homes are inter-war or post-war semis and detached houses with room for rear and side extensions, while historic town centres and villages bring conservation area and listed building controls.

What do you get with a garden annexe?

We design annexes as permanent buildings with proper foundations, insulation and services, and we prepare the planning case showing how the annexe will be used as part of the main home. Connections for water, drainage and power are planned from the start.

  • Foundations and drainage connections
  • Heating, hot water and electrics
  • Accessible design options for older relatives

How much does a garden annexe cost in Horsham?

Use these ranges to budget for garden annexes; the survey turns them into a fixed price for the agreed specification.

Garden annexesGuide 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 £3,900 per m²

Do you need permission for a garden annexe in Horsham?

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.

A self-contained annexe used for sleeping and living normally needs planning permission in England. Permitted development for outbuildings does not cover living accommodation.

What can change the price or programme?

  • Drainage may need a pump if the garden falls away from the sewer.
  • A level threshold and wider doors make the annexe suitable for later life.

From first call to completion

  1. Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
  2. Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
  3. Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
  4. 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 garden annexe in Horsham

How much does a garden annexe cost?

Around £2,400 to £3,900 per square metre including VAT, depending on finish and services.

Can I rent the annexe out?

Usually not without a separate planning permission, because councils normally require it to stay part of the main house.

Can you visit a house in Horsham to quote?

Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.

Other towns nearby

Learn more about garden annexes, or see every project we cover in Horsham.

Planning an extension, loft or new home?

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