ADU · Erie County

Can you build an ADU in Buffalo, NY?

City of Buffalo has 4 districts. All districts allow ADUs. Check your address to confirm the district that applies to your parcel:

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What the Buffalo code says

Buffalo handles the accessory unit as a named building type. A carriage house is permitted in every district here, either as an ancillary building behind the principal structure or as a principal building on its own lot.

Conditions the code attaches:

An ancillary carriage house sits 10 ft back from the principal structure, with 0 ft side and rear yards
As a principal building it may stand on a lot as small as 600 square feet and 15 ft wide
An ancillary one may encroach into the principal building's required yards if all accessory structures occupy no more than 50% of any one required yard and it stands at least 18 inches from a lot line
Confirm the use standards with Permit and Inspection Services at (716) 851-4949

What the Buffalo code indicates by district

The table below shows how each district treats ADUs, alongside the lot and setback standards that govern a second unit. District boundaries and conditions vary, so treat this as a starting point and confirm the district that applies to your parcel.

District	Min lot	Setbacks F / S / R	Max height	ADU
N-2R Residential	0.034 ac	- / 3 / - ft	40 ft	As of right
N-3R Residential	0.041 ac	- / 3 / - ft	40 ft	As of right
N-4-30 Single-Family	0.055 ac	- / 3 / - ft	40 ft	As of right
N-4-50 Single-Family	0.092 ac	- / 6 / - ft	40 ft	As of right

N-2R Residential - The figures shown are the detached house standards, and a building of another type carries different ones. The front yard is contextual, within plus or minus 5 ft of the established front yard line on the block, with at least 65% of the front facade on that line.

The two side yards must total 20% of the lot width, and the 3 ft shown is a floor beneath that percentage
The rear yard is 15% of the lot depth, and no fixed figure is published for it
The lot width has a maximum as well as a minimum: a lot may be no more than 60 ft wide
Impervious coverage may not exceed 80%, a second cap alongside the building coverage figure that counts drives and walks
Height is three storeys as well as 40 ft, and the finished ground floor must sit between 0 and 4 ft above grade
§ 3.2.1.G carries height exceptions along specified sections of Delaware Avenue, Gates Circle and North Street here

N-3R Residential - The figures shown are the detached house standards, and a building of another type carries different ones. The front yard is contextual, within plus or minus 5 ft of the established front yard line on the block, with at least 65% of the front facade on that line.

The two side yards must total 20% of the lot width, and the 3 ft shown is a floor beneath that percentage
The rear yard is 20% of the lot depth, and no fixed figure is published for it
The lot width has a maximum as well as a minimum: a lot may be no more than 75 ft wide
Impervious coverage may not exceed 80%, a second cap alongside the building coverage figure that counts drives and walks
Height is three storeys as well as 40 ft, and the finished ground floor must sit between 0 and 4 ft above grade

N-4-30 Single-Family - The figures shown are the detached house standards, and a building of another type carries different ones. The front yard is contextual, within plus or minus 5 ft of the established front yard line on the block, with at least 65% of the front facade on that line.

The two side yards must total 20% of the lot width, and the 3 ft shown is a floor beneath that percentage
The rear yard is 25% of the lot depth, and no fixed figure is published for it
The lot width has a maximum as well as a minimum: a lot may be no more than 75 ft wide
Impervious coverage may not exceed 70%, a second cap alongside the building coverage figure that counts drives and walks
Height is three storeys as well as 40 ft, and the finished ground floor must sit between 0 and 4 ft above grade

N-4-50 Single-Family - The figures shown are the detached house standards, and a building of another type carries different ones. The front yard is contextual, within plus or minus 5 ft of the established front yard line on the block, with at least 65% of the front facade on that line.

The two side yards must total 20% of the lot width, and the 6 ft shown is a floor beneath that percentage
The rear yard is 25% of the lot depth, and no fixed figure is published for it
Impervious coverage may not exceed 60%, a second cap alongside the building coverage figure that counts drives and walks
Height is three storeys as well as 40 ft, and the finished ground floor must sit between 0 and 4 ft above grade

ADUs vs. short-term rentals in Buffalo

Short-term rentals allowed with local rules for City of Buffalo. Renting a home short term needs both a city short-term rental license and a certificate under Ch. 380, Short-Term Rental Housing, adopted 2-20-2024. These are separate questions from whether you can build an ADU — a unit you're allowed to add isn't automatically one you're allowed to rent nightly, so check both.

Good to know

Residential lot minimum0.034–0.092 ac — an ADU still has to fit the district's lot and setback envelope.
UtilityNational Grid territory.
Zoning codeecode360.com/attachment/319204/Buffalo_UDO.pdf
Building dept(716) 851-4949

ADU FAQ — Buffalo, NY

Are ADUs allowed in Buffalo, NY?

City of Buffalo has 4 districts. All districts allow ADUs. Check your address with the free ADU checker, or confirm with the building department at (716) 851-4949.

Do I need a special permit for an ADU in Buffalo?

No district in City of Buffalo requires a special-use permit for an ADU - 4 districts allow ADUs. Site-plan review or a building permit may still apply.

Can I use an ADU as a short-term rental in Buffalo?

Short-term rentals allowed with local rules for City of Buffalo. ADU occupancy and short-term-rental rules are separate: an ADU you can build isn't automatically one you can rent nightly. Confirm both before you count on STR income.

Run the free ADU check for your parcel →

What an ADU costs to build in Buffalo

Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $200k–260k at a standard finish, and the per-square-foot rate comes in above a full house because the kitchen, bath, panel and heating plant cost the same either way. See the full cost to build an ADU in Buffalo, priced by size.

How we know this

Zoning code: ecode360.com/attachment/319204/Buffalo_UDO.pdf
Districts confirmed: 4 of 4 — every mapped district.
Last reviewed: 2026-08-06
Not covered here: Overlay districts, the zoning map, and any conditions attached to an individual parcel. Size limits and owner-occupancy terms sit in the code section above, not in this summary.

More on Buffalo: Full zoning for new construction · ADU build cost · House build cost · ADU rules across Erie County · All Erie County towns

ADU information for City of Buffalo is compiled from the municipal code (last reviewed 2026-08-06) and provided for decision-support only — not legal or architectural advice. ADU eligibility, size, owner-occupancy and permit conditions vary by district and often carry exceptions; verify with the building department at (716) 851-4949 before relying on any answer. Source: the Offsite / Aldo zoning dataset.