Shed Permit Requirements in Alabama

Alabama's Split Threshold: 120 vs. 200 Square Feet

Alabama's shed permit rules start at the state level with the 2021 Alabama Building Code, which follows the International Building Code's standard exemption: one-story detached accessory structures under 120 square feet used as tool and storage sheds, playhouses, and similar uses don't require a building permit.

But Alabama allows local jurisdictions to amend this threshold, and several have. Mobile County raised the exemption to 200 square feet through a detailed local amendment that adds conditions beyond just size. The City of Madison (near Huntsville) also uses a 200-square-foot threshold. Meanwhile, Birmingham, Huntsville, Montgomery, and many other cities stick with the state's 120-square-foot standard.

The practical difference is significant. Under the 120-square-foot threshold, a standard 10×12 shed (120 square feet) is right at the limit — anything larger needs a permit. Under the 200-square-foot threshold, you can build up to a 10×20 without a permit. Knowing which threshold your city uses is the first step in planning your shed project. For how Alabama compares nationally, see our complete guide to shed permits.

Mobile County's Detailed Amendment

Mobile County's approach to shed permit exemptions is worth examining because it shows how a local jurisdiction can create more nuanced rules than the base state code. Mobile County's amendment exempts one-story detached accessory structures that meet all of the following conditions:

• Are Risk Category I storage sheds or playhouses
• Do not exceed 200 square feet under roof
• Do not contain conditioned space (no heating or air conditioning)
• Are not served by any utility — electrical, water, fuel gas, solar, wind, or other alternative energy sources
• Are not located in a Special Flood Hazard Area regulated by the Mobile County Flood Damage Prevention Ordinance
• Are not located in Wind Exposure Category D (oceanfront properties)

The last two conditions are critical for coastal Alabama. Properties along the Gulf of Mexico that face direct hurricane exposure don't get the 200-square-foot exemption — every shed needs a permit in those areas, regardless of size.

How Five Alabama Cities Handle Shed Permits

Birmingham: Standard 120-Square-Foot Threshold

Birmingham follows the state's 120-square-foot threshold. The city's building department requires a permit for any accessory structure exceeding 120 square feet. All sheds, regardless of size, must comply with zoning setback requirements.

Birmingham's permit fees are valuation-based, typically running $75–$200 for a standard residential shed. The review process takes 5–10 business days for a complete application. Contractors must hold a valid Alabama home builder's license and a current Birmingham business license.

Huntsville: Clear Placement Rules

Huntsville follows the 120-square-foot threshold and provides clear, specific placement rules for accessory structures. Sheds must be in the rear yard, at least 5 feet from side and rear property lines, off any easements, and at least 10 feet from any other structure including the main house.

Accessory structures in Huntsville cannot exceed two stories. Plumbing in sheds is limited to one commode and one lavatory. On corner lots, sheds must meet the secondary front yard setback, which varies by zoning district — contact the Inspection Department at (256) 427-5341 for your specific requirement.

Huntsville's permit fees are modest, typically $50–$150 based on valuation, with reviews completed in 3–7 business days.

Montgomery: Zoning for All Sizes

Montgomery uses the 120-square-foot state threshold and requires zoning compliance for all accessory structures. The city's planning department reviews site plans to verify setbacks, lot coverage, and compliance with the zoning ordinance. Sheds over 120 square feet need both zoning approval and a building permit.

Permit fees in Montgomery are valuation-based, running $50–$150 for typical shed projects. Review time is 5–10 business days.

Mobile: 200-Square-Foot Local Amendment

Mobile and Mobile County use the expanded 200-square-foot exemption described above. The conditions are stricter than a simple size threshold — the shed must have no utilities, no conditioned space, and must not be in a flood zone or Wind Exposure Category D.

For sheds that do need a permit, Mobile County requires property owners to pass a basic electrical safety questionnaire before they can self-permit electrical work on their own residence's accessory structures. This requirement — administered by the county's building department — is unusual in Alabama and reflects the county's emphasis on electrical safety in a humid, storm-prone climate.

Permit fees are valuation-based, typically $75–$200.

Madison: 200-Square-Foot Threshold with Planning Review

Madison (a rapidly growing city near Huntsville) uses a 200-square-foot threshold. The city requires homeowners to contact the Planning Department at (256) 772-5630 for specific setback requirements before placing any shed. The Planning Department also checks whether the property is in a historic or overlay district that could require additional approvals.

Madison specifically notes that both pre-built and site-built sheds over 200 square feet require a building permit, and recommends that homeowners in HOA communities check their covenants for additional restrictions.

Alabama's Home Builders Licensure Law

Alabama's Home Builders Licensure Law adds a layer that many states don't have: it requires residential construction to be performed by a licensed residential home builder. This applies to any work that requires a building permit, including shed construction.

Homeowners can claim an exemption by completing a Sworn Statement of the Property Owner Claiming Exemption. The key conditions:

• You own the property
• The structure is for your personal use and occupancy, not for sale or rent
• If you sell within one year of completion, the law presumes you built for sale — a violation
• You cannot hire or compensate anyone to supervise the construction
• All subcontractors must hold proper state licenses
• You waive your rights under the General Contractors Licensure Law in the event of litigation

The exemption form must be completed and returned to the building department before the permit is issued. This is required in most Alabama jurisdictions, including Baldwin County, Huntsville, and Mobile.

Wind and Storm Considerations

Alabama faces hurricane risk along its Gulf Coast (Mobile and Baldwin counties) and severe thunderstorm and tornado risk across the rest of the state. The building code addresses these risks through:

• Wind load requirements — sheds in coastal areas must be designed for the local design wind speed, which ranges from about 115 mph inland to 150+ mph along the immediate coast
• Anchoring requirements — sheds must be secured against wind uplift, with anchoring standards that increase in coastal wind zones
• Flood zone compliance — sheds in FEMA flood zones must meet floodplain management requirements, including elevation or flood opening specifications

Tornadoes are a year-round risk in Alabama. While the building code's wind provisions primarily address sustained hurricane winds rather than tornado-specific forces, properly anchored and constructed sheds are more resistant to all forms of wind damage.

Flood Zone Requirements

Alabama has extensive flood hazard areas, particularly along the Gulf Coast, the Tennessee River valley in northern Alabama, and numerous river and creek corridors across the state. Properties in FEMA-designated Special Flood Hazard Areas must comply with local floodplain management ordinances.

For sheds in flood zones:

• The structure must either be elevated to or above the Base Flood Elevation (BFE) or include flood openings that allow water to flow through
• Mobile County explicitly excludes sheds in flood zones from its 200-square-foot permit exemption — all sheds need a permit in these areas
• Some counties require an Elevation Certificate for accessory structures over a certain size in flood zones

Septic System Considerations

Many Alabama properties, particularly in Baldwin County and rural areas, use septic systems. When placing a shed on a property with a septic system, you must avoid encroaching on the septic tank, distribution lines, or designated repair area.

Baldwin County's building department notes that any questions about septic tank locations and clearances should be directed to the Alabama Onsite Wastewater Board. The required clearance varies but is commonly 10 feet from the tank and 20 feet from the drain field.

HOA Restrictions

Alabama's suburban growth — particularly in Huntsville, Madison, the Birmingham suburbs (Hoover, Vestavia Hills), and the Mobile/Baldwin County area — has brought a significant increase in HOA-governed communities. Madison, Huntsville, and the Birmingham suburbs are especially dense with master-planned developments that have detailed architectural standards.

Common HOA shed restrictions include material and color matching, placement in rear yards only, mandatory screening, and size limits that may be more restrictive than the building code threshold. The City of Madison explicitly recommends checking HOA covenants before planning any shed project.

Consequences of Building Without a Permit

Building without a required permit in Alabama can result in:

• Stop-work orders and penalty fees
• Requirement to remove the structure if it violates zoning, flood zone, or wind exposure rules
• Sale complications — Alabama real estate transactions routinely include inspections that flag unpermitted structures
• Licensing violations — if a contractor builds without a permit, the Home Builders Licensure Board can take disciplinary action

Permit fees in Alabama are modest. A typical shed permit runs $50–$200 depending on the city and the project's valuation. Zoning reviews for small exempt sheds are typically free.

If you're also planning a garage or carport alongside your shed, each structure needs its own permit and must comply with setback and lot coverage requirements.

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