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 Portslade?
In Portslade, a garage conversion typically costs £20,000–£33,500 for a single integral garage, including VAT at 20% (standard rate). The guide for Portslade reflects typical costs in the South East, roughly 12% above the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A single integral garage | £20,000–£33,500 |
| Higher specification | £33,500–£42,000 |
The main things that change the cost:
- Integral, attached or detached
- Single or double garage
- Whether planning permission is needed
- Bathroom or kitchen
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 Portslade?
Approvals for a garage conversion in Portslade 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.
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
What we take care of:
- Foundation check under the garage door opening
- Wall and ceiling insulation
- New wall and window to replace the garage door
- Electrics, heating and plastering
- Drawings and building control application
- Floor raised with insulation and damp-proof membrane
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 Portslade
Commuter towns across the South East have many 1930s and post-war semis that suit rear extensions and hip-to-gable loft conversions.
From BN41 outwards, we take on projects throughout Portslade and the surrounding parts of East Sussex.
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 Portslade
Who approves a garage conversion in Portslade?
Planning matters in Portslade 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.
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.
How much does a garage conversion cost in Portslade?
In Portslade, a garage conversion typically costs £20,000–£33,500 for a single integral garage, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
