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 Streatham?
In Streatham, 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 Streatham 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:
- Heating and flooring
- Whether planning permission is needed
- Foundations under the old door opening
- Integral, attached or detached
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 Streatham?
Approvals for a garage conversion in Streatham follow the rules for 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
From survey to sign-off, the job normally involves:
- Foundation check under the garage door opening
- New wall and window to replace the garage door
- Floor raised with insulation and damp-proof membrane
- Drawings and building control application
- Building control completion
- Electrics, heating and plastering
How long does it take?
Build time is typically 3 to 6 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Streatham
Many London boroughs have conservation areas and detailed design guides, so early design advice saves time at the planning stage.
Projects in Streatham (SW16) are surveyed in person before we quote, so the price reflects your actual property.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 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 handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about garage conversions in Streatham
Will losing the garage affect parking?
Councils sometimes object if on-street parking is under pressure. We check local parking standards.
Can the floor be level with the house?
Yes. The garage floor is raised and insulated to match the house floor level.
How long does a garage conversion take in Streatham?
Typically 3 to 6 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
How much does a garage conversion cost in Streatham?
In Streatham, 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.
