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 Twickenham?
In Twickenham, a garage conversion typically costs £23,500–£39,000 for a single integral garage, including VAT at 20% (standard rate). Building costs in London run about 30% above the UK average, and the figures for Twickenham are adjusted to reflect that. 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:
- Bathroom or kitchen
- Whether planning permission is needed
- Heating and flooring
- Integral, attached or detached
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 Twickenham?
Whether you need planning permission depends on your house and its location 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
What we take care of:
- New wall and window to replace the garage door
- Foundation check under the garage door opening
- Floor raised with insulation and damp-proof membrane
- Building control completion
- Drawings and building control application
- Planning check for removed permitted development rights
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 Twickenham
Victorian and Edwardian terraces dominate many London streets, which is why side return, wraparound and mansard projects are so common here.
From TW1 outwards, we take on projects throughout Twickenham and the surrounding parts of Greater London.
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
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about garage conversions in Twickenham
How much does a garage conversion cost in Twickenham?
In Twickenham, 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.
How long does a garage conversion take in Twickenham?
Typically 3 to 6 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
Can the floor be level with the house?
Yes. The garage floor is raised and insulated to match the house floor level.
Will losing the garage affect parking?
Councils sometimes object if on-street parking is under pressure. We check local parking standards.
