The two consents, and which one applies
Scotland runs two separate systems. Planning permission controls land use and appearance. A building warrant controls construction standards. A garage conversion usually escapes the first and never escapes the second.
| Planning permission | Building warrant | |
|---|---|---|
| Controls | Land use and external appearance | Structure, energy, ventilation, fire and escape |
| Usually needed for a conversion? | No | Yes, always |
| Issued by | Council planning service | Council building standards service |
| Ends with | A decision notice | A completion certificate |
When planning permission is required
- —A planning condition on the original house requires the garage to be retained for off-street parking. This is common on newer Glasgow housing estates and is the most frequent trigger.
- —The property is listed, or sits in a conservation area, and the works alter the front elevation.
- —The conversion creates a separate dwelling — for example a self-contained annexe let independently of the house.
- —Permitted development rights have been removed from the property by an earlier planning condition or an Article 4 direction.
Check the original planning decision for your house, or ask the council's planning service, before any work is ordered. Verify the current thresholds against the official guidance at mygov.scot and Glasgow City Council building standards, since rules and fee scales change.
What the building warrant covers
- —Thermal performance of the new floor, walls, ceiling and infill wall
- —Structural adequacy of the infill wall, any new lintel and the existing roof
- —Ventilation provision, including extract where washing or cooking is added
- —Fire safety and escape, including window sizes where the room is used for sleeping
- —Electrical safety, certified by a registered electrician
The warrant process, step by step
- —Measured survey and drawings of the existing garage and the proposed room
- —Warrant application submitted to the council with the fee
- —Council review, and any requests for further information answered
- —Warrant granted — work can now legally start
- —Stage inspections during the build, typically at damp-proofing and pre-plaster
- —Completion certificate submitted and accepted, closing the warrant
A warrant is generally granted in six to eight weeks in Glasgow, which is why it sets the length of the overall programme rather than the construction work itself.
Why the completion certificate matters
The completion certificate is the document a solicitor asks for when you sell. A converted garage without one becomes a conveyancing problem, and buyers routinely negotiate down or withdraw. We close every warrant we open, and hand the certificate to you at the end of the job.