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 Windsor?
In Windsor, 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 |
The main things that change the cost:
- Single or double garage
- Foundations under the old door opening
- Whether planning permission is needed
- Bathroom or kitchen
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a garage conversion in Windsor?
Before anything is built in Windsor, 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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
What we take care of:
- Drawings and building control application
- Floor raised with insulation and damp-proof membrane
- Wall and ceiling insulation
- Planning check for removed permitted development rights
- Electrics, heating and plastering
- Building control completion
How long does it take?
Expect 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 Windsor
The South East has a broad mix of housing, from Victorian terraces in the towns to post-war semis and newer estates, so extension types vary street by street.
We work across Windsor and neighbouring areas such as Slough, Egham and Staines. Postcodes we cover in Windsor include SL4.
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
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 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 Windsor
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.
How much does a garage conversion cost in Windsor?
In Windsor, 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 Windsor?
Typically 3 to 6 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
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.
Will losing the garage affect parking?
Councils sometimes object if on-street parking is under pressure. We check local parking standards.