What a carport actually stops
- Hail: yes
- UV and paint fade: yes
- Direct rain and snow: yes
- Wind-driven rain from the side: no
- Dust and pollen: no
- Theft: no
- Temperature: partially, mostly by blocking sun
Cost comparison at the same footprint
| Configuration | 20 x 25 | 24 x 35 | What you get |
|---|---|---|---|
| Open carport | Baseline | Baseline | Overhead cover only |
| One side closed | About 19 percent more | About 19 percent more | Blocks prevailing weather |
| Two sides closed | About 36 percent more | About 36 percent more | Tunnel style, good wind protection |
| Fully enclosed garage | About 88 percent more | About 88 percent more | Lockable, insulatable, heatable |
The deciding question
Will you spend time inside the building doing something other than getting in and out of a vehicle?
If yes, build the garage. Wind, dust, and temperature make an open structure miserable to work in, and the cost of retrofitting walls onto an existing carport is higher than building them the first time.
If no, the carport does the job for half the money and goes up in a day.
Resale
An enclosed garage on a permanent slab generally contributes to appraised value. An open carport on ground anchors is usually treated as personal property, not a real property improvement.
If resale value is part of your reasoning, that difference is worth more than the cost gap.