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 Ruislip?
In Ruislip, a garage conversion typically costs £23,500–£39,000 for a single integral garage, including VAT at 20% (standard rate). The guide for Ruislip reflects typical costs in London, roughly 30% above the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A single integral garage | £23,500–£39,000 |
| Higher specification | £39,000–£49,000 |
The biggest cost drivers are:
- Heating and flooring
- Bathroom or kitchen
- Whether planning permission is needed
- Single or double garage
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 Ruislip?
Here is how the rules work for a garage conversion 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.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
Handled as part of most garage conversions:
- Drawings and building control application
- Wall and ceiling insulation
- Floor raised with insulation and damp-proof membrane
- New wall and window to replace the garage door
- Foundation check under the garage door opening
- Planning check for removed permitted development rights
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 Ruislip
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
Projects in Ruislip (HA4) are surveyed in person before we quote, so the price reflects your actual property.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about garage conversions in Ruislip
How much does a garage conversion cost in Ruislip?
In Ruislip, a garage conversion typically costs £23,500–£39,000 for a single integral garage, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Do I need planning permission for a garage conversion?
Usually not if the work is internal and the house keeps its permitted development rights. Many newer houses have planning conditions that remove those rights, in which case an application is needed.
Can a detached garage be converted?
Yes, but using it as separate living accommodation may need planning permission.
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.
How long does a garage conversion take in Ruislip?
Typically 3 to 6 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
