What is a garage conversion?

A garage conversion turns an integral or attached garage into habitable space, such as a study, playroom, bedroom or utility. The garage door is replaced with a wall and window, the floor is raised and insulated, and the walls and roof are brought up to building regulations.
How much does a garage conversion cost in Horley?
In Horley, a garage conversion typically costs £20,000–£33,500 for a single integral garage, including VAT at 20% (standard rate). That range is adjusted for the South East, where domestic building work typically costs around 12% above the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A single integral garage | £20,000–£33,500 |
| Higher specification | £33,500–£42,000 |
Your quote will depend mainly on:
- Whether planning permission is needed
- Heating and flooring
- Bathroom or kitchen
- Foundations under the old door opening
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a garage conversion in Horley?
Before anything is built in Horley, we confirm which approvals apply in England. In England converting an integral or attached garage usually does not need planning permission, unless a condition on the house removed permitted development rights (common on estates built in recent decades) or the house is listed. Building regulations approval is always needed.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
Handled as part of most garage conversions:
- Planning check for removed permitted development rights
- Electrics, heating and plastering
- New wall and window to replace the garage door
- Drawings and building control application
- Floor raised with insulation and damp-proof membrane
- Building control completion
How long does it take?
Allow 3 to 6 weeks on site. Before that, surveys, drawings and approvals usually take 6 to 12 weeks, longer if the council asks for changes.
Building in Horley
Commuter towns across the South East have many 1930s and post-war semis that suit rear extensions and hip-to-gable loft conversions.
Projects in Horley (RH6) are surveyed in person before we quote, so the price reflects your actual property.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about garage conversions in Horley
Do I need building regulations approval?
Yes. Converting a garage to a habitable room needs building control approval for insulation, ventilation, fire safety and the new wall.
Can the floor be level with the house?
Yes. The garage floor is raised and insulated to match the house floor level.
Can a detached garage be converted?
Yes, but using it as separate living accommodation may need planning permission.
How much does a garage conversion cost in Horley?
In Horley, a garage conversion typically costs £20,000–£33,500 for a single integral garage, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
How long does a garage conversion take in Horley?
Typically 3 to 6 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
