Guide
What homeowners need to know.
A garage is not automatically housing
The city will care about habitability, safety, energy, structure, and utilities. Paint and flooring do not convert a garage. Nice try.
Permits need real drawings
Plans should show layout, egress, fire separation, mechanical, electrical, plumbing, insulation, and how the conversion meets current requirements.
Existing conditions drive cost
Old slabs, low ceilings, drainage issues, nonconforming openings, and utility upgrades can turn a cheap-looking conversion into a serious project.
Cost table
Use ranges until scope is real.
| Item | Planning range | Why it moves |
|---|---|---|
| Plans and permit support | $10k-$35k+ | Depends on existing structure and city comments. |
| Construction range | $120k-$300k+ | Driven by structural, moisture, utility, fire, and finish requirements. |
| Utility upgrades | Variable | Electrical, sewer, water, and meter work can materially change the budget. |
Mistakes
Avoid these expensive shortcuts.
- Assuming the garage slab is ready for finished living space.
- Skipping fire separation and egress review.
- Not checking whether replacement parking rules or exemptions apply.
- Pricing finishes before code blockers are known.
FAQ
Fast answers.
Do garage conversions need permits?
Yes. A legal ADU garage conversion needs permits and drawings showing the space meets building, fire, energy, utility, and city requirements.
Sources