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 Mill Hill?
In Mill Hill, 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:
- Whether planning permission is needed
- Bathroom or kitchen
- Integral, attached or detached
- Foundations under the old door opening
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 Mill Hill?
Before anything is built in Mill Hill, 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.
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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
The work we manage on a garage conversion:
- Planning check for removed permitted development rights
- Wall and ceiling insulation
- Foundation check under the garage door opening
- New wall and window to replace the garage door
- Drawings and building control application
- Building control completion
How long does it take?
Build time is typically 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 Mill Hill
Victorian and Edwardian terraces dominate many London streets, which is why side return, wraparound and mansard projects are so common here.
Our Mill Hill coverage includes postcode districts NW7, and we also work in nearby places such as Edgware, Hendon and Finchley.
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 fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about garage conversions in Mill Hill
How long does it take?
Typically 3 to 6 weeks on site.
Can the floor be level with the house?
Yes. The garage floor is raised and insulated to match the house floor level.
How much does a garage conversion cost in Mill Hill?
In Mill Hill, 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.
Who approves a garage conversion in Mill Hill?
Planning matters in Mill Hill go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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.