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 Welwyn Garden City?
In Welwyn Garden City, a garage conversion typically costs £19,000–£32,000 for a single integral garage, including VAT at 20% (standard rate). We start from a UK-wide guide and adjust it for the East of England, where labour and materials are typically about 6% above average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A single integral garage | £19,000–£32,000 |
| Higher specification | £32,000–£40,000 |
Your quote will depend mainly on:
- Bathroom or kitchen
- Single or double garage
- Whether planning permission is needed
- Integral, attached or detached
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a garage conversion in Welwyn Garden City?
The approval route for Welwyn Garden City is set by planning law 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
Handled as part of most garage conversions:
- Electrics, heating and plastering
- Floor raised with insulation and damp-proof membrane
- Drawings and building control application
- Building control completion
- Wall and ceiling insulation
- Planning check for removed permitted development rights
How long does it take?
The build itself usually takes 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 Welwyn Garden City
Many towns in the East of England have estates built since the 1970s, where garage conversions and rear extensions are popular.
We work across Welwyn Garden City and neighbouring areas such as Hatfield, Hertford and St Albans. Postcodes we cover in Welwyn Garden City include AL8.
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 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 Welwyn Garden City
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.
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 much does a garage conversion cost in Welwyn Garden City?
In Welwyn Garden City, a garage conversion typically costs £19,000–£32,000 for a single integral garage, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Do you build garage conversions in Welwyn Garden City?
Yes. We build garage conversions across Welwyn Garden City, including postcodes AL8. Every project starts with a free home visit.
