Carports are popular as roofed parking spaces, but they are treated as structures under the Building Standards Act. If you do not confirm the building coverage ratio correctly before installation, you could, in the worst case, be required to remove or rebuild the structure.
What is the difference between a carport and a garage?
A carport is a simple roofed parking structure made up only of posts and a roof. By contrast, anything with walls, shutters, or doors is classified as a garage. This distinction also affects fixed asset tax treatment.
Is a building confirmation application required to install a carport?
Yes. A carport is subject to the Building Standards Act as a structure with a floor area of 10 square meters or more, so a building confirmation application is required. If a structure is built in violation of the building coverage ratio, it may be treated as an illegal building and be subject to removal or rebuilding. In the confirmation review, the “area from post to post” is calculated as the building area.
How is the building coverage ratio calculated?
The building coverage ratio is the percentage of the building area relative to the site area, and the maximum allowed ratio is set by zoning area.
Building coverage ratio (%) = building area ÷ site area × 100
Example: If the site area is 100㎡ and the building coverage ratio is 40%, the allowable building area is 40㎡. If a house already exists on the site, the carport must be installed within the remaining allowable area.
What should you keep in mind when installing a carport?
Confirm the space required for parking
A typical guideline for a one-car carport is 2.5 m wide, 5 m deep, and 2.1 m high or more. Be sure to leave enough room for opening and closing the doors as well.
Some municipalities offer building coverage ratio relaxations
Depending on the municipality, relaxation measures may apply if conditions are met, such as a post spacing of 2 m or more, an open side of 4 m or more without walls, a ceiling height of 2.1 m or more, and a single-story structure. It is essential to confirm the requirements with the municipality in advance.
Watch for issues with neighboring properties
In areas with heavy snow or rain, the direction of the carport roof slope may cause accumulated snow to fall onto the neighboring lot. Check the property boundary carefully before deciding on the placement.
Carports are not subject to fixed asset tax
Because a carport is not enclosed by walls or doors, it is not subject to fixed asset tax. A garage, however, may be taxable.
You may also want to read
- Guide to building area, building coverage ratio, and floor area ratio
- Comprehensive guide to apartment security measures
- What are rent reduction guidelines?
Frequently Asked Questions (FAQ)
Q1. Is a building confirmation application required even for a small carport?
A building confirmation application is required for a carport with a floor area of 10 square meters or more. However, outside fire prevention and quasi-fire prevention districts, an extension under 10 square meters may not require one.
Q2. What happens if the building coverage ratio is exceeded?
The structure may be treated as a building code violation, and you may be instructed to remove or rebuild it. It can also create problems when selling the property, so confirming compliance before installation is essential.
Q3. Are carport building coverage ratio relaxations the same nationwide?
No. The conditions for relaxation measures differ by municipality. Be sure to confirm them with your city or ward's building guidance department before installation.
Q4. Which is more cost-effective, a carport or a garage?
In general, a carport can be installed at a lower cost and is not subject to fixed asset tax. A garage offers better security and protection, but it may be subject to fixed asset tax.
