Why there's no real "small carport" exemption
The WA Building Regulations exempt small freestanding structures from a building permit: 10 m² or less and no taller than 2.4 m. Some websites say a carport can use this. On paper it can, but look at the size of a car space:
| Size | Area | |
|---|---|---|
| Exemption limit | e.g. 3.2 m x 3.1 m | 10 m² |
| Minimum car space (City of Stirling) | 5.4 m x 2.4 m | about 13 m² |
A real car won't fit under a 10 m² roof. That's why councils like Stirling and Wanneroo simply say a carport always needs a building permit. The exemption also only covers freestanding structures, and most carports are fixed to the house.
What size avoids planning approval?
This is the question that matters more. Planning approval isn't about a size limit; it's about whether the carport meets the standard rules for your lot. Most carports skip it if they:
- Take up no more than 60% of the lot's frontage.
- Keep a clear view between the house and the street (open sides, no solid doors).
- Sit at least the reduced street setback. At Wanneroo, the normal setback (6 m at R20, 4 m at R30 to R40) can be halved for a carport that meets the frontage, open-sides and matching-materials rules.
- Aren't on a heritage-listed property or in a heritage area.
Posts on a side boundary can also be allowed. Wanneroo accepts this for carports no longer than 10 m and no higher than 2.7 m, with the roof set 500 mm back. More on carports in the front setback.
So what should you do?
Plan on a building permit for any carport you can park a car under. For most, the council fees are about $183 in total. If yours is in the front setback or near the boundary, check the planning rules before you buy a kit, because that's where carports get refused.