Do I need a permit in Ann Arbor, MI?
Ann Arbor uses the 2015 International Building Code with Michigan amendments, which means most residential projects — decks, additions, roof work, electrical upgrades, fence repairs — do require a permit. The city's Building Department processes permits through their online portal, and they're generally thorough: plan reviews average 2-3 weeks for routine residential work, and inspections are required before cover-up (drywall, concrete pour, etc.). The city's frost depth of 42 inches — deeper than the IRC standard of 36 inches in Climate Zone 5A — affects deck footings and foundation work; footing inspections tend to happen May through September, when the ground is accessible. Ann Arbor also has stronger-than-average tree-preservation rules and wetland sensitivity, which can trigger additional environmental reviews for larger projects. The permit fee structure is based on project valuation at roughly 1.5% of the estimated cost, with a $75 minimum for most residential permits. Owner-builders can pull permits on their own occupied home, but licensed contractors must pull permits for any work they're hired to do — and the city enforces this actively.
What's specific to Ann Arbor permits
Ann Arbor's online permit portal is live and functional — you can file, pay, and track inspections entirely online for most residential projects. This speeds things up compared to paper filing. However, the portal's backend sometimes requires clarification calls before the system accepts your application; the Building Department's phone line can get backed up on Tuesdays and Wednesdays, so call early in the week if you're stuck.
The city enforces owner-builder restrictions strictly. If you hire a contractor, the contractor must pull the permit — not you. The city cross-checks contractor licensing through LARA (Michigan's licensing board), and they'll flag any work pulled under the homeowner's name that clearly exceeds owner-builder scope. This doesn't stop homeowners from doing the work themselves after permit issuance; it just means the permit application must be honest about who's doing the work.
Ann Arbor's wetland and tree-preservation rules are more aggressive than many Michigan cities. If your property sits within 500 feet of a wetland or you're removing a tree over 20 inches in diameter, you may need environmental review on top of your building permit. This adds 2-4 weeks to the timeline and sometimes requires a site-plan review. Check the city's environmental-review maps before you file — they're available online and save surprises later.
Footing inspections in Ann Arbor are mandatory and must happen before you pour concrete or backfill. The city's frost depth of 42 inches (versus the IRC's 36-inch standard) is non-negotiable; footing bottoms must clear 42 inches minimum. This means deck footings, foundation trenches, and utility trenches all go deeper than you might expect. Inspectors are strict about this because of Michigan's freeze-thaw cycle.
The Building Department is responsive to email but prefers phone contact for permit-status questions. In-person visits to the counter are possible but only during specific hours (verify current hours locally). The department processes over-the-counter permits for small projects like fence repairs and shed additions if your plans are simple and complete; expect to wait 15-30 minutes at the counter.
Most common Ann Arbor permit projects
These projects account for the majority of residential permits the city issues. All require permits and inspections; none are exempt in Ann Arbor.
Decks
Any attached deck or patio requires a permit. Ann Arbor's 42-inch frost depth drives footing depth; shallow footings are the #1 reason for inspection failure. Detached decks under 200 square feet with no roof or railing may qualify for expedited review in some cases.
Fences
Fences over 4 feet in side or rear yards and any fence in front-yard setbacks require permits. Corner-lot sight triangles are strictly enforced. Masonry walls over 3 feet also need permits. Permit fees run $75–$150 depending on linear footage.
Roof replacement
Full roof replacement requires a permit and inspection. Minor repairs (under 25% of roof area) may be exempt if you're not changing the structural assembly, but the safest move is to call the department before you start. The city requires a final inspection before occupancy.
Electrical work
All electrical work beyond simple fixture replacement requires a permit and inspection. Panel upgrades, new circuits, and generator installations need licensed electrician involvement. The city enforces NEC 2020 with Michigan amendments; inspectors are strict about ground-fault protection and arc-flash labeling.
Room additions
Any addition or finished basement conversion needs a permit, site plan, and structural review. Plan review averages 3 weeks. The department requires electrical and mechanical permits as separate subpermits if you're adding HVAC or circuits.