Buffalo's Accessory Structures: The Rules That Matter
Every city handles accessory structures a little differently. In Buffalo, New York, there are 9 distinct rules that residents and property owners should be aware of. Some are stricter than what neighboring cities enforce, and others are more relaxed. Here is what you need to know.
Shed Rules
Sheds up to 144 square feet in Buffalo may be installed without a building permit but still must meet setback and rear-yard coverage rules. Larger sheds require a building permit from Permit and Inspection Services.
Key details: No-permit size: 144 sq ft or less. Setback: 3-5 ft typical. Rear coverage: ~30% max. Height: 12-15 ft. Historic: COA may apply.
Unpermitted oversized shed: stop-work order plus fines up to 250 dollars. Zoning violations (setback, coverage): 100-500 dollars plus required removal.
Tiny Homes
Tiny homes on permanent foundations may be permitted in Buffalo as primary dwellings or ADUs if they meet NYS Building Code minimums. Tiny homes on wheels (THOWs) are treated as recreational vehicles and cannot be used as permanent residences.
Key details: On foundation: Allowed with permit. Appendix Q: NYS code for <400 sf. THOW: RV only, not residence. ADU option: Under 800 sq ft cap. Utilities: Must connect to city.
Using a THOW as a permanent residence: zoning violation, fines up to 500 dollars per day, and orders to vacate. Unpermitted tiny-home construction: stop-work plus penalties.
Garage Conversions
Garage conversions to habitable space or ADUs are allowed in Buffalo with a building permit, Certificate of Occupancy amendment, and compliance with egress, insulation, and ceiling-height rules. Historic districts require extra review.
Key details: Permit: Required. Ceiling: 7 ft minimum. Egress: Window per bedroom. CofO: Must be updated. Parking: May need replacement.
Unpermitted conversion: stop-work, fines up to 500 dollars per day, and mandatory restoration or legalization. Missing CofO updates void property insurance in many cases.
ADU Rules
Buffalo Unified Development Ordinance (Green Code) permits accessory dwelling units (ADUs) in most residential zones. ADUs must be on lots at least 2,500 sq ft, occupy no more than 800 sq ft, and meet parking and design standards. Owner-occupancy of the primary dwelling is required.
Key details: Max size: 800 sq ft or 33% of main. Min lot: 2,500 sq ft. Owner-occupancy: Required. STR use: Prohibited. Code: Green Code UDO.
Unpermitted ADU construction: stop-work order plus fines up to 500 dollars per day. STR use of an ADU triggers separate short-term-rental penalties.
Carport Rules
Carports in Buffalo are treated as accessory structures. Permanent carports require a building permit; temporary fabric carports are generally disallowed as long-term installations. Setback and coverage rules match those for garages and sheds.
Key details: Permanent: Permit required. Fabric: Not allowed long-term. Height: 15 ft max. Setback: 3-5 ft. Historic: Preservation Board review.
Unpermitted permanent carport: stop-work and fines up to 250 dollars. Tube-frame/fabric carports kept beyond short-term use are cited as PMCNYS property maintenance violations.
ADU Impact Fees
Buffalo does not levy a dedicated ADU impact fee. The City charges standard building, plumbing, electrical, and gas permit fees through the Department of Permit and Inspection Services, scaled to construction valuation. Water and sewer connection charges through the Buffalo Sewer Authority and Buffalo Water apply only when new service is installed for the ADU.
Key details: Dedicated ADU Impact Fee: None in Buffalo. Permit Fee Basis: Construction valuation. Utility Connections: Buffalo Water / Sewer Authority charges if new service. ADU Incentive Program: Buffalo Urban Renewal Agency. Collection Point: At permit issuance and inspection.
Failure to pay required permit fees prevents permit issuance and any lawful ADU construction. Unpermitted utility connections discovered by Buffalo Water or Buffalo Sewer Authority can result in disconnection, back-billing, and code enforcement action through the Department of Permit and Inspection Services.
If you are coming from a city with tighter rules, you will find Buffalo gives residents more flexibility on adu impact fees.
ADU Permits
Buffalo permits accessory dwelling units (ADUs) under the Unified Development Ordinance (UDO), known as the Green Code, codified at Chapter 496 of the Buffalo City Code. Detached, attached, and internal ADUs are recognized configurations. Applicants must obtain building, plumbing, electrical, and zoning approvals through the Department of Permit and Inspection Services and comply with the New York State Uniform Code.
Key details: Governing Ordinance: Buffalo UDO Chapter 496 (Green Code). Permit Authority: Dept. of Permit and Inspection Services. ADU Configurations: Detached, attached, or internal. Height Limit: 15 ft single-story / 30 ft two-story. Building Code: NY State Uniform Code (19 NYCRR).
Constructing or occupying an ADU without permits issued by the Department of Permit and Inspection Services violates Chapter 496 and the New York State Uniform Code, triggering stop-work orders, daily fines under the city code, and required removal or legalization. Unpermitted electrical, plumbing, or gas work can void homeowner insurance coverage. Failure to obtain a certificate of occupancy prevents lawful habitation of the unit.
ADU Rental Restrictions
Buffalo ADUs may be rented for long-term residential occupancy (six months or more) by the owner-occupant. Short-term rentals (less than six months) are governed separately by Chapter 380 of the Buffalo City Code, which requires registration through the Department of Permit and Inspection Services. Non-owner-occupied STR operation requires a special use permit approved by the Common Council.
Key details: STR Ordinance: Buffalo Code Chapter 380. STR Definition: Less than 6 months. Owner-Occupied STR Fee: $150 first / $75 renewal. Non-Owner STR: Special use permit required. Liability Insurance: $1 million minimum.
Operating a Buffalo ADU as an unregistered short-term rental violates Chapter 380 and is subject to fines of approximately $500 per occasion, plus zoning enforcement under Chapter 496. Failure to maintain $1 million liability insurance or to register a local agent can result in registration revocation. Long-term landlords must comply with the City's rental registry and lead-safe housing requirements where applicable.
ADU Owner Occupancy
Buffalo requires that the property owner occupy either the primary dwelling or the accessory dwelling unit as their principal residence. This owner-occupancy mandate applies at the time of permit issuance and on a continuing basis. Investor-only ADU configurations where no owner lives on the lot are not allowed under the current Green Code framework.
Key details: Owner-Occupancy: Required (primary or ADU). Governing Code: UDO Chapter 496 (Green Code). Proof of Residency: STAR, voter reg, license address. Investor-Only ADUs: Not permitted. Cross-Reference: STR Chapter 380 special use rules.
Operating an ADU without owner-occupancy violates Chapter 496 and may trigger zoning enforcement, revocation of the certificate of occupancy, and daily fines. The Department of Permit and Inspection Services can require legalization through a special use permit (if pursued via Chapter 380 for short-term rental) or order the unit returned to non-dwelling use. Sale of the property without disclosure of the occupancy condition can create civil liability.
Compared to other cities, Buffalo takes a harder line on adu owner occupancy. The enforcement and penalty structure reflects that.
The Bottom Line
Buffalo's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Buffalo is broadly strict or permissive.
Keep in mind that Buffalo can amend these rules at any council meeting. For the most current version of any rule mentioned here, check the specific ordinance page, where we track updates as they happen.