Building permits, zoning and land rules in Allegheny County, Pennsylvania

Pennsylvania's Uniform Construction Code applies statewide, and work covered by it needs a building permit before construction begins¹. In Allegheny County, the township, borough or city where the project lies takes the building-permit application; the county assessment office only directs applicants there². Inspections cover residential and commercial construction, electrical, gas, mechanical and plumbing systems, and pools and hot tubs¹. A UCC certificate of occupancy must be issued before a covered building or facility can be used¹. The state's UCC triennial update took effect January 1, 2026, so ask the municipal code official which code edition applies to your plans⁹. A qualifying agricultural building with no habitable space is excluded from the state Construction Code Act, though municipal zoning may still apply¹⁰. Zoning also stays municipal, and septic permits stay with Allegheny County Health Department Sewage Enforcement Officers^3,4.

The township, borough or city where the work occurs issues the building permit in Allegheny County². Allegheny County's Office of Property Assessments receives municipal building, demolition and occupancy permits for assessment purposes, but directs applicants to the municipality for building-permit types and fees². Use the parcel address to identify the municipality, then ask which building-code official or certified third-party agency accepts the UCC building-permit application¹. Municipal zoning approval also stays local, while county Health Department review still applies to septic permits and plumbing permits^3,4,14. Allegheny County publishes a Health Department plumbing fee schedule effective 1/1/2023¹⁴. That schedule does not cover municipal building permits, so ask the municipality for its building-permit fees¹⁴. Plumbing work may start only after plan approval and permit issuance, with an inspection as work proceeds and a final inspection for every plumbing permit¹⁴. Commercial plumbing plans need Commercial Plan Review preapproval before filing¹⁴.

Zoning requirements in Allegheny County are determined by the township, borough or city where the parcel lies³. Marshall Township and Findlay Township have their own zoning ordinances; county septic permitting remains with Allegheny County Health Department in both townships^4,15,16. Aspinwall Borough and Aleppo Township also have zoning chapters of their own^17,18. Ask the municipal zoning office for the parcel’s district, permitted uses and dimensional requirements; we could not confirm a countywide answer for setbacks, lot size or tiny-home occupancy. County Planning separately administers the county Subdivision and Land Development Ordinance for municipalities without their own ordinance¹⁹. A development with at least 11 single-family lots using on-lot sewage requires the municipality to create a sewage management district⁵.

Allegheny County Health Department Sewage Enforcement Officers issue septic permits for on-lot sewage systems throughout Allegheny County, including addresses inside its municipalities⁴. A county septic permit is required before construction related to installing, altering, repairing or extending an individual or community on-lot system begins⁵. A narrow state exemption may apply to an owner or immediate-family residence on a contiguous tract of at least 10 acres, but ownership-date, notice and siting conditions still control²⁰. Only about 11.6% of county soils avoid severe limitations for a conventional drain field, so establish feasibility early rather than assuming a standard system will fit²¹. A completed sewage system cannot be covered until the original permit issuer or authorized representative approves it, subject to the state's response-period rule²². Properties close to an available public sewer may have to connect instead⁵.

We could not confirm a countywide answer in Allegheny County for residential RV use, temporary camping or tiny-home occupancy on private land. The parcel's township, borough or city zoning office must answer for that location because zoning is handled locally^6,23. O'Hara Township prohibits temporary occupancy of an RV or motor home parked or stored there and bars using an RV as living quarters⁷. In the City of Pittsburgh's floodplain Zones A and AE, an RV must stay fewer than 180 consecutive days and remain licensed and highway-ready, or meet the manufactured-home permit requirements; we could not confirm whether that amendment is currently effective⁸. A manufactured home's UCC treatment does not settle local siting permission²⁴. A composting or incinerating toilet does not eliminate wastewater review for a new residence²⁵.

1. Identify the parcel's township, borough or city, then obtain that municipality's zoning approval and building-permit instructions^2,3.
2. Confirm the proposed use, setbacks and subdivision status with municipal zoning staff; contact County Planning if the county subdivision ordinance applies¹⁹.
3. Ask whether public sewer service is available because county rules can require nearby properties to connect⁵.
4. If the site will use on-lot sewage, obtain the county septic permit through Allegheny County Health Department before construction begins^4,5,12.
5. For UCC-regulated construction in a floodplain, have a registered design professional prepare and seal the required building-code documentation¹.
6. Obtain the correct highway occupancy permit for access involving a county right-of-way or a Commonwealth highway^26,27.
7. File the UCC building-permit application with the municipal administrator before starting regulated work¹.
8. Complete the required building inspections and obtain the UCC certificate of occupancy before using the building; completed public electric or gas service requires written proof that the structure passed its inspections^1,27.

Start with municipal identity: it determines the zoning office, building-permit administrator and local building-permit fees, while county septic authority does not change at municipal lines^2,3,4. Ask whether a proposed split or development needs municipal review or the county subdivision process¹⁹. For a parcel without public sewer service, make sewage-system feasibility part of due diligence because a county septic permit is required before constructing or altering an on-lot system and only about 11.6% of county soils avoid severe conventional drain-field limitations^5,21. Verify proximity to an available public sewer because county rules may require connection⁵. UCC construction in a floodplain needs building-code documentation prepared and sealed by a registered design professional, but that is a documentation condition, not a full floodplain permit process¹. The municipality evaluates whether a project lies in a Special Flood Hazard Area and issues the floodplain development permit before work begins¹³. Determine who owns the road before designing access: construction in a county right-of-way requires a county highway occupancy permit, while driveway access to a Commonwealth highway requires a PennDOT highway occupancy permit^26,27.