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 Westminster?
In Westminster, a garage conversion typically costs £23,500–£39,000 for a single integral garage, including VAT at 20% (standard rate). We start from a UK-wide guide and adjust it for London, where labour and materials are typically about 30% above 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 |
The main things that change the cost:
- Heating and flooring
- Integral, attached or detached
- 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 Westminster?
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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
On a typical garage conversion we handle:
- Wall and ceiling insulation
- New wall and window to replace the garage door
- Electrics, heating and plastering
- Building control completion
- Planning check for removed permitted development rights
- Drawings and building control application
How long does it take?
The build itself usually takes 3 to 6 weeks on site. Design and approvals come first and typically take 6 to 12 weeks, depending on the approval route.
Building in Westminster
Victorian and Edwardian terraces dominate many London streets, which is why side return, wraparound and mansard projects are so common here.
From SW1 outwards, we take on projects throughout Westminster and the surrounding parts of Greater London.
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 Westminster
How much does a garage conversion cost in Westminster?
In Westminster, 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.
How long does a garage conversion take in Westminster?
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.
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.