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 Feltham?
In Feltham, a garage conversion typically costs £23,500–£39,000 for a single integral garage, including VAT at 20% (standard rate). That range is adjusted for London, where domestic building work typically costs around 30% above the national average. 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 |
What moves the price most:
- Bathroom or kitchen
- Foundations under the old door opening
- Heating and flooring
- Whether planning permission is needed
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a garage conversion in Feltham?
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.
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.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
Handled as part of most garage conversions:
- Floor raised with insulation and damp-proof membrane
- Wall and ceiling insulation
- New wall and window to replace the garage door
- Planning check for removed permitted development rights
- Foundation check under the garage door opening
- Drawings and building control application
How long does it take?
The build itself usually takes 3 to 6 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Feltham
Victorian and Edwardian terraces dominate many London streets, which is why side return, wraparound and mansard projects are so common here.
If your home is in Feltham or close by in Hounslow, Ashford and Sunbury-on-Thames, a free home visit is the first step.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 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 Feltham
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 much does a garage conversion cost in Feltham?
In Feltham, 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.
Can a detached garage be converted?
Yes, but using it as separate living accommodation may need planning permission.
Who approves a garage conversion in Feltham?
Planning matters in Feltham go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Can the floor be level with the house?
Yes. The garage floor is raised and insulated to match the house floor level.
