Residential permit rules in Michigan
Representative cities: Detroit, Grand Rapids. Covers 16 common home projects.
| Project | Permit? | Authority | Typical fee | Timeline | Go / No-Go | Key notes |
|---|---|---|---|---|---|---|
| 🏠 Accessory Dwelling Unit (ADU) | Permit required | city | Building permit based on project valuation; verify with the city. Detroit issues residential permits in about 5 days. | Typically 5–15 business days; Detroit ~5 days, Grand Rapids 5–10 days for simple projects. | Generally allowed | ADUs are allowed in Michigan subject to local zoning. A building permit and zoning approval are required; some cities cap size and occupant/rental rules. Confirm with Detroit or Grand Rapids planning. Exempt: No state size exemption for an ADU (it is habitable space). |
| 🪵 Deck / Porch | Conditional | city | Valuation-based building permit; verify with the city. | Typically 5–15 business days; Detroit ~5 days. | Generally allowed | Footings must extend below the frost line — 42 in in the Detroit/Grand Rapids area. Guards required at 30 in+ above grade. Verify setback and lot coverage with the city. Exempt: State R105.2 exempts decks ≤200 sq ft, ≤30 in above grade, not attached, not within 36 in of the dwelling, and not serving egress. |
| 🧱 Fence / Wall | Conditional | city | Typically a zoning/building permit fee; verify with the city. | Often issued in days to 1–2 weeks. | Generally allowed | Michigan exempts fences up to 7 ft under the state code, but cities set their own height/yard limits and may require a zoning review. Always check local ordinance and HOA. Exempt: State R105.2 exempts fences 7 ft high or less (Detroit: 7 ft or less, not in a Special Review District). |
| 🛖 Shed / Outbuilding | Conditional | city | Valuation-based where required; structures <200 sq ft often use a lower-compliance permit. | Often 5–10 business days; smaller sheds may be issued faster. | Generally allowed | Small detached storage sheds are usually exempt, but adding electricity/plumbing or exceeding 200 sq ft triggers a permit. Confirm setbacks with the city. Exempt: State R105.2 exempts one-story detached accessory structures ≤200 sq ft. Grand Rapids: <200 sq ft = Planning Accessory Structure Permit; ≥200 sq ft = building permit. |
| 🪜 Basement Finish | Permit required | city | Valuation-based building permit; verify with the city. | Plan review typically 2–4 weeks plus inspections. | Generally allowed | Converting a basement to living space requires permits for framing, egress, electrical, plumbing, and mechanical. Egress windows are required for bedrooms. Exempt: n/a |
| 🚗 Garage / Carport | Permit required | city | Valuation-based building permit; verify with the city. | Plan review typically 2–4 weeks plus inspections. | Generally allowed | New detached or attached garages and carports require a building permit and zoning/setback review. Exempt: Detroit exempts detached accessory structures ≤200 sq ft; new garages over that need a permit. |
| ☀️ Rooftop Solar PV | Permit required | city | Electrical (and structural) permit per city schedule; verify locally. | Often 1–3 weeks; some jurisdictions expedite residential PV. | Generally allowed | Residential rooftop solar PV requires an electrical (and often structural/mechanical) permit plus utility interconnection approval. Exempt: Any grid-tied rooftop PV system requires a permit. |
| 🌡️ HVAC Replacement | Permit required | city | Mechanical permit fee per city schedule; verify locally. | Usually 1–2 weeks; light plan review, straightforward inspection. | Generally allowed | Replacing or upgrading HVAC equipment requires a mechanical permit and inspection before energizing. Exempt: Any furnace, AC, or heat-pump replacement/installation requires a permit. |
| 🍳 Kitchen Remodel | Permit required | city | Building + trade permits based on valuation; verify with the city. | Plan review typically 2–4 weeks plus trade inspections. | Generally allowed | Kitchen remodels moving plumbing/electrical or altering walls require building, plumbing, and electrical permits. Exempt: Any layout/plumbing/electrical change requires a permit. |
| 🛁 Bathroom Remodel | Permit required | city | Building + trade permits based on valuation; verify with the city. | Plan review typically 1–3 weeks plus trade inspections. | Generally allowed | Bathroom remodels that move fixtures, add ventilation, or alter plumbing/electrical require permits. Exempt: Any fixture relocation or new wet wall requires a permit. |
| 🏗️ Room Addition | Permit required | city | Building permit based on valuation plus trade permits; verify with the city. | Plan review typically 3–6 weeks plus multiple inspections. | Generally allowed | Room additions change the footprint and require foundation, framing, egress, and trade reviews. Historic districts need a Certificate of Appropriateness. Exempt: Any new conditioned square footage requires a full permit. |
| 🪟 Window / Door Replacement | Conditional | city | Building permit (alteration) where required; verify with the city. | Often 1–2 weeks; many window jobs are issued without plan review. | Generally allowed | Replacing windows/doors in the same opening is typically exempt; enlarging an opening or cutting a new one requires a permit. Exempt: In-kind replacement in the same opening is often exempt. |
| 🏘️ Roof Replacement | Permit required | city | Building permit (re-roof) per city schedule; verify locally. | Often 1–2 weeks; inspection after decking/underlayment and after shingles. | Generally allowed | Detroit requires a permit for roof replacement. Other jurisdictions vary — verify locally before starting. Exempt: Detroit requires a permit for roof replacement (removal of substantial shingles). |
| 🅿️ Driveway / Parking Pad | Conditional | city | Permit fee where required; verify locally. | Often 1–2 weeks; right-of-way review can add time. | Generally allowed | New or widened driveways, curb cuts, and right-of-way work typically require a permit and possibly stormwater review. Exempt: State R105.2 exempts sidewalks/driveways ≤30 in above adjacent grade and not over a basement. |
| 🏊 Swimming Pool / Spa | Conditional | city | Building + electrical permit per city schedule; verify locally. | Plan review typically 2–4 weeks plus inspections. | Generally allowed | Pools require a building permit and code-compliant barrier (self-closing/self-latching gate). Electrical permit for wiring. Exempt: State R105.2 exempts prefab pools <24 in deep, ≤5,000 gal, installed entirely above ground. |
| 🧱 Retaining Wall | Conditional | city | Building permit where required; verify with the city. | 1–3 weeks; walls over threshold may need engineered drawings. | Generally allowed | Retaining walls holding more than 4 ft of fill require a permit and often professional design. Check HOA and drainage too. Exempt: State R105.2 exempts retaining walls ≤4 ft measured from bottom of footing to top (unless supporting a surcharge). |