Residential permit rules in New York

Representative cities: New York City, Buffalo. Covers 16 common home projects.

Project	Permit?	Authority	Typical fee	Timeline	Go / No-Go	Key notes
🏠 Accessory Dwelling Unit (ADU)	Permit required	city	Permit and plan-review fees set by the city. Verify with the local building department.	Varies by city; NYC ADU filings may take several weeks.	Restricted	New York has no statewide by-right ADU mandate; ADUs are allowed where local law permits (e.g., the NYC ADU program, Buffalo). Zoning applies. Exempt: Allowed only where the local law permits.
🪵 Deck / Porch	Conditional	city	Set by the city — typically a flat plus valuation-based fee. Verify with the city building department.	1–4 weeks (NYC files through DOB NOW).	Generally allowed	Attached or raised decks need a permit; NYC requires a DOB filing. Exempt: Decks >30 in above grade require a permit (RCNYS R105).
🧱 Fence / Wall	Conditional	city	Usually no building permit under local height limits; zoning setback rules apply. Verify locally.	Same day / Over-the-Counter where required.	Generally allowed	Height/front-yard rules set by local zoning and HOA covenants. Exempt: Typically no building permit under local height limits (zoning).
🛖 Shed / Outbuilding	Conditional	city	No fee under the exemption; a permit fee applies if over the threshold.	Same day / Over-the-Counter where required.	Generally allowed	Larger or serviced sheds need a building permit. Exempt: One-story detached accessory structure ≤120 sq ft is exempt (RCNYS R105.2).
🪜 Basement Finish	Permit required	city	Valuation-based building permit fee. Verify with the city building department.	2–6 weeks.	Generally allowed	Finishing a basement requires egress (RCNYS R310) and permits; a sleeping room needs a code-compliant egress window. Exempt: N/A
🚗 Garage / Carport	Permit required	city	Valuation-based fee. Verify with the city building department.	2–8 weeks.	Generally allowed	A new garage requires a building permit under the RCNYS / NYC Building Code. Exempt: N/A
☀️ Rooftop Solar PV	Permit required	city	Electrical permit fee set by the city. Verify with the city building department.	2–4 weeks (NYC files through DOB NOW).	Generally allowed	Rooftop PV requires an electrical permit; NYC files through DOB NOW. Exempt: N/A
🌡️ HVAC Replacement	Permit required	city	Mechanical permit fee set by the city. Verify with the city building department.	1–2 weeks.	Generally allowed	Furnace, AC, or heat-pump replacement requires a mechanical permit and inspection. Exempt: N/A
🍳 Kitchen Remodel	Permit required	city	Building + electrical + plumbing permit fees. Verify with the city building department.	NYC: ALT2 review, several weeks.	Restricted	NYC: kitchen/bath renovation needs an ALT2 permit filed by a NYS-licensed PE or RA; upstate follows similar building-permit rules. Exempt: N/A
🛁 Bathroom Remodel	Permit required	city	Building + plumbing + electrical fees. Verify with the city building department.	NYC: ALT2 review, several weeks.	Restricted	NYC: bathroom renovation needs an ALT2 permit filed by a NYS-licensed PE or RA; fixture-only swaps may be exempt. Exempt: N/A
🏗️ Room Addition	Permit required	city	Valuation-based building permit; impact fees may apply. Verify with the city building department.	3–8 weeks.	Generally allowed	Expanding the footprint requires full plan review; NYC uses New Building / ALT1 filings. Exempt: N/A
🪟 Window / Door Replacement	Conditional	city	Permit fee if changing the opening; in-kind swap is often exempt.	Same day / Over-the-Counter where required.	Generally allowed	Enlarging openings or changes to means of egress need a permit (NYC PE/RA filing). Exempt: In-kind same-size replacement generally needs no permit.
🏘️ Roof Replacement	Conditional	city	Roofing permit fee set by the city. Verify with the city building department.	1–3 weeks.	Generally allowed	Re-roofing generally requires a permit; NYC requires a roofing permit. Minor repair may be exempt. Exempt: N/A
🅿️ Driveway / Parking Pad	Conditional	city	Private flatwork generally needs no building permit; curb cut / right-of-way needs a separate permit.	Varies.	Generally allowed	A curb cut or work in the public right-of-way requires a separate permit from the city / public works. Exempt: N/A
🏊 Swimming Pool / Spa	Permit required	city	Building permit + electrical; fee set by the city. Verify with the city building department.	3–8 weeks.	Generally allowed	Pools require a permit and barrier per RCNYS R328 (barrier, alarms, entrapment protection). Exempt: N/A
🧱 Retaining Wall	Conditional	city	No fee under the exemption; a permit applies if over the threshold.	2–4 weeks if required.	Generally allowed	Taller or surcharge-supporting walls need design and a permit. Exempt: Retaining walls ≤4 ft (bottom of footing to top), not supporting a surcharge, are exempt (RCNYS R105.2).

State-wide sources: NYS Dept. of State — Uniform Code / Building Standards & Codes (FAQ) · NYC Department of Buildings — Acquire Permits