Building a Shed in Michigan? Here's When You Need a Permit

Michigan's 200-Square-Foot Threshold

Michigan's statewide residential building code sets one of the more generous shed permit exemptions in the country. Under the Michigan Residential Code (Part 5 of the Michigan Construction Code, administered by LARA), one-story detached accessory structures under 200 square feet do not require a building permit on residential properties.

This is notably higher than the 120-square-foot threshold in the base International Residential Code that many states follow. The 200-square-foot exemption means a standard 10×20 shed — large enough for a riding mower, workbench, and seasonal storage — can be built without a building permit in most of Michigan.

But the 200-square-foot line is just the building permit threshold. Two important caveats apply:

• Zoning compliance is almost always required. Nearly every Michigan city and township requires a zoning permit for any accessory structure, even those under 200 square feet. The zoning review verifies setbacks from property lines, lot coverage limits, and compliance with the local zoning ordinance.
• The structure must still meet code. Exemption from a building permit does not mean exemption from the construction code. A shed under 200 square feet must still comply with applicable structural requirements, material standards, and safety provisions.

For how Michigan's threshold compares to other states, see our national guide to shed permits.

The Two-Code Distinction

Michigan actually has two different permit exemption thresholds, and the one that applies to you depends on whether the shed is on residential or commercial property:

• Michigan Residential Code (Part 5): Exempts one-story accessory structures under 200 square feet on residential properties
• Michigan Building Code (Part 4): Exempts one-story accessory structures under 120 square feet on commercial and non-residential properties

For homeowners, the 200-square-foot residential threshold is the relevant one. But if you're building a shed on commercial or mixed-use property, the threshold drops to 120 square feet.

How Five Michigan Cities Handle Shed Permits

Detroit: Minimum $150 Permit Fee

Detroit follows the state's 200-square-foot threshold. Sheds larger than 200 square feet or taller than one story require a building permit from the Buildings, Safety Engineering and Environmental Department (BSEED).

Detroit's permit fee structure starts at a minimum of $150, with an additional $20 per $1,000 of construction value above $2,000. For a typical shed valued at $4,000, the permit would cost approximately $190. The city requires three complete sets of construction drawings and a site plan showing all existing and proposed structures with distances to property lines.

Detroit's plan review for standard shed permits takes 1–3 business days. The city uses the 2015 Michigan Construction Codes and requires all contractors to be registered with the state. Homeowners can act as their own contractor for work on their primary residence.

Grand Rapids: Health Department Review for Septic Properties

Grand Rapids requires an Accessory Structure permit for sheds 200 square feet or larger. The permit application includes construction plans, a site plan, and zoning review. The permit fee is based on the total project value including materials and labor, plus a zoning review fee.

Grand Rapids adds an extra step for properties with well and septic systems: the application must include a Kent County Environmental Health Review Form confirming that the shed location doesn't interfere with the well or septic system components. This review can add a few days to the process.

For sheds under 200 square feet, Grand Rapids still requires a zoning compliance review to verify setbacks and lot coverage. The zoning review is typically completed within a few business days.

Ann Arbor: Zoning Compliance for Every Shed

Ann Arbor has a clear two-tier system. Sheds 200 square feet or larger require a building permit — the application costs $100 for projects up to $1,000 in value, with fees increasing based on the estimated project cost. Sheds under 200 square feet require a Zoning Compliance Permit at a cost of $75, which includes one inspection.

Ann Arbor's zoning rules for accessory buildings are detailed. Sheds in residential districts must be placed in the rear yard, at least 3 feet from any lot line (though structures over 200 square feet may need greater setbacks due to fire rating standards). The maximum height for accessory buildings is 21 feet, measured from the midpoint of the roof.

Properties in Ann Arbor's historic districts must obtain approval from the Historic District Commission before a building permit can be issued. This applies to sheds that are visible from the street and can add several weeks to the timeline.

Ann Arbor's zoning compliance permit review takes approximately 3 business days. Building permit reviews for larger sheds take 2–4 weeks for the initial review, with resubmittals taking 1–2 weeks.

Sterling Heights: Concrete Slab and Height Restrictions

Sterling Heights has some of the most detailed accessory building regulations in Metro Detroit. All accessory buildings with a floor area over 50 square feet must be installed on a concrete slab at least 3.5 inches thick. Sheds cannot exceed 15 feet in height on lots of a quarter acre or less, and shed openings (doors) cannot exceed 6 feet in width.

The number and total size of accessory structures allowed depends on lot size:

• Lots of a quarter acre or less: One garage (attached or detached) plus one shed up to 200 square feet. Total detached accessory building area cannot exceed 700 square feet.
• Lots over a quarter acre but under a half acre: Up to 1,000 square feet total accessory building area.
• Lots over a half acre: Up to 2,000 square feet total, with an additional 200 square feet allowed for each additional quarter acre.

Sterling Heights requires in-person permit applications — online applications are not available for accessory structures. The typical permit fee is $75–$200 based on the project's valuation.

Livonia: Rat Wall Requirements

Livonia enforces distinctive requirements that reflect practical concerns specific to Michigan's climate and suburban environment. The city requires a 4-inch-wide, 24-inch-deep poured concrete rat wall around the perimeter of all sheds and accessory buildings. If a concrete slab is not poured inside the rat wall, the top of the wall must extend at least 4 inches above grade.

Livonia also caps total accessory structure area: the combined ground floor area of all accessory structures — including attached and detached garages — cannot exceed 920 square feet. A maximum of two accessory structures are allowed on properties under a half acre.

Sheds may be placed as close as 2 feet from side and rear lot lines, provided there is no easement. The city requires a zoning permit application with three copies of a plot plan for all sheds, regardless of size. Permit fees run $75–$150 depending on the project.

Michigan's 42-Inch Frost Depth

Michigan's frost depth — the depth to which the ground freezes in winter — is a minimum of 42 inches below outside finished grade. This is among the deepest in the lower 48 states and has direct implications for shed construction.

For sheds that require a building permit (200 square feet or larger), the frost depth matters in several ways:

• Frost-free foundations (poured concrete footings, post foundations) must extend at least 42 inches below finished grade to prevent frost heave — the expansion and contraction of frozen soil that can lift and shift structures.
• Floating mat foundations (concrete slabs that sit on the ground surface) are limited in size. Most jurisdictions allow floating mat foundations only for structures under 400–600 square feet, and some construction types reduce this further.
• Post foundations (pole barn style) require each post to be set to a minimum depth of 42 inches, with a pre-set or pre-cast concrete pad at least 6 inches thick beneath each post.

For smaller sheds that don't require a building permit, the frost depth still matters practically. A shed placed on concrete blocks or skids that sit on the ground surface will shift seasonally as the ground freezes and thaws. This is cosmetically annoying (doors may not close properly in winter) and can cause structural stress over time. Setting blocks or piers below the frost line eliminates this problem but adds significant labor and cost.

Rat Walls: A Michigan Specialty

If you've never lived in Michigan, the concept of a rat wall may be unfamiliar. A rat wall is a narrow concrete barrier — typically 4 inches wide — poured around the perimeter of a shed's foundation. It extends at least 24 inches below grade and serves a simple purpose: preventing rodents from burrowing under the shed.

Many Michigan cities require rat walls for all accessory structures, including sheds under 200 square feet. Livonia, Oak Park, and several other Metro Detroit suburbs have explicit rat wall requirements in their zoning ordinances. The requirements typically specify:

• Minimum 4 inches wide
• Minimum 24 inches deep below finished grade
• Top of wall at least 4 inches above grade if no interior slab is poured
• The shed's treated-wood floor frame is attached directly to the top of the rat wall

Rat walls add $200–$500 to the cost of a shed installation depending on the perimeter length and local concrete prices. For a standard 10×12 shed, expect about 44 linear feet of rat wall.

This is one of those requirements that feels onerous until you've seen what happens without it. Michigan's winters drive rodents to seek sheltered spaces, and an unprotected shed floor becomes a nesting ground for mice, rats, and other burrowing animals.

Pre-Built vs. Site-Built Sheds

Michigan treats pre-built and site-built sheds the same for permitting purposes — the 200-square-foot threshold applies regardless of how the shed is constructed. However, there are practical differences in how the two types interact with local requirements:

Pre-built sheds are delivered to the site fully assembled or in large sections. They're typically placed on a prepared foundation (concrete blocks, piers, or a rat wall). The advantage is speed and simplicity — the manufacturer handles the structural design, and the homeowner needs only to prepare the site and obtain permits. The downside is that pre-built sheds are limited in size by what can be transported on a truck, and they may not include the rat wall or frost-depth foundation that some Michigan cities require.

Site-built sheds are constructed on the property from raw materials or kits. They require more construction skill and time but can be built to any size and can incorporate a permanent foundation from the start. For sheds over 200 square feet, site-built construction makes it easier to integrate the required frost-depth footings and inspections into the build process.

Both types require the same zoning review. Both must meet the same setback, lot coverage, and height requirements.

Snow Load Considerations

Michigan's snow loads are significant and affect shed design. The design snow load varies by location — the Lower Peninsula generally sees 25–40 pounds per square foot of ground snow load, while the Upper Peninsula and lake-effect zones can exceed 60 pounds per square foot.

For sheds that require a building permit, the structural design must account for the local snow load. This affects the roof framing — truss spacing, rafter size, and ridge beam specifications. Pre-built shed manufacturers typically rate their structures for a specific snow load, and the inspector will verify that the rating meets or exceeds the local requirement.

For smaller sheds that don't require a permit, snow load is still a practical concern. A flat-roofed or low-pitched shed in Michigan's snow belt will accumulate heavy snow loads that can cause the roof to sag or collapse. Sheds with steeper roof pitches (6:12 or higher) shed snow more effectively and are better suited to Michigan's climate.

Agricultural Exemptions

Michigan law provides a building permit exemption for certain agricultural buildings under Michigan Compiled Laws § 125.1510. Buildings that are incidental to the agricultural use of the land and not used for retail business or commercial trade may be exempt from standard building permits.

This exemption applies to structures on active farms — barns, equipment sheds, grain storage buildings, and similar agricultural buildings. It does not apply to a suburban homeowner's storage shed, even on a large lot with a garden. The agricultural use must be genuine and the land must be actively used for farming.

Even with the agricultural exemption, the structure must comply with local zoning setbacks and land use requirements. Some townships in rural Michigan also require site plan approval for agricultural buildings, even when a building permit is not required.

HOA Restrictions in Michigan

Michigan's suburban communities — particularly in Oakland, Macomb, and Washtenaw counties — are heavily governed by Homeowners Associations. HOA restrictions on sheds commonly include:

• Material requirements (wood or vinyl only — metal sheds may be prohibited)
• Color and style matching with the main dwelling
• Maximum size limits (often well below the 200-square-foot permit threshold)
• Screening requirements — the shed may need to be invisible from the street
• Placement restrictions beyond what zoning requires

Michigan's Homeowners Association Act gives associations enforcement power over their covenants. Many Michigan cities explicitly note in their shed permit guides that "building construction may require Neighborhood Association approval" and that the city does not get involved in disputes between homeowners and their associations.

Consequences of Building Without a Permit

Building a shed without required permits in Michigan carries consequences:

• Stop-work orders and requirement to obtain a retroactive permit, often with doubled fees
• Forced removal if the shed violates zoning setbacks or lot coverage limits
• Failed occupancy or sale inspections — unpermitted structures are flagged during home sales and can delay or prevent closing
• Liability exposure — if an unpermitted shed causes injury (a roof collapses under snow load, for example), the homeowner faces increased legal exposure
• Property tax issues — the assessor may discover the structure and retroactively adjust the property's assessed value

Michigan's shed permit costs are modest. Zoning permits for small sheds run $50–$100. Building permits for larger sheds typically start at $100–$200. The consequences of skipping the permit are disproportionately expensive.

Before you dig, Michigan law requires you to call Miss Dig 811 to have underground utilities marked. This is free and takes 3–5 business days. Hitting a buried gas line or electrical conduit while installing a shed foundation is dangerous and expensive.

If you're also planning a garage or carport alongside your shed, remember that most Michigan cities cap the total floor area of all accessory structures combined. Plan your projects together to stay within the limits.

For an overview of all building permit requirements in Michigan — including decks, fences, pools, and more — see our complete Michigan building permit guide.