Can I Build ADU in Pittsburgh, PA? (2026)
Find out if you can build a adu in Pittsburgh, PA. Rules, permit requirements, costs, and next steps.
Yes, ADUs are allowed in Pittsburgh, PA. California state law ensures by-right approval.
An Accessory Dwelling Unit (ADU) is a secondary housing unit on a residential lot — also called a granny flat, in-law suite, or backyard cottage. In Pittsburgh, PA, ADUs are permitted by right under state law, making them one of the most accessible ways to add housing on your property. ADUs can be detached, attached to the main home, or created by converting an existing garage or accessory structure.
ADU Rules in Pittsburgh
ADU Rules in Pittsburgh: Detached ADU max size: 800 sq ft. Attached ADU max size: 30% of primary dwelling floor area. Setbacks: 3 ft side, 5 ft rear. Owner-occupancy: No owner-occupancy requirement for accessory dwelling units in Pittsburgh. Investment properties can have ADUs..
Costs & Fees
ADU permits in Pittsburgh: Total estimated permit cost: $1,500–$5,000 total permit fees. Contact the Pittsburgh Permits, Licenses, and Inspections (PLI) for current fee schedule.
Timeline
Pittsburgh DCP building permit: typically 4-8 weeks. Pittsburgh Permits, Licenses, and Inspections (PLI) handles building permits. Construction 3-9 months.
Next Steps
Next steps for building an ADU in Pittsburgh: 1. Review full ADU rules including size limits, setbacks, and parking. 2. Apply for an ADU permit through the Pittsburgh Permits, Licenses, and Inspections (PLI) at https://aca-prod.accela.com/PITTSBURGH/. 3. Hire a licensed contractor familiar with PA ADU requirements.
Pittsburgh Permits, Licenses, and Inspections (PLI)
Phone: (412) 255-2175
Website: https://pittsburghpa.gov/pli
Online Permits: https://aca-prod.accela.com/PITTSBURGH/
Frequently Asked Questions
Can I build an ADU on my Pittsburgh property?
Yes — Pittsburgh allows accessory dwelling units on residential lots. You can build a detached ADU up to 800 sqft in the rear or side yard, or convert a portion of your house into an attached ADU. No owner-occupancy requirement, no additional parking needed, and no impact fees. Pittsburgh's PLI issues building permits, typically taking 4-8 weeks for review.
What are Pittsburgh's short-term rental rules?
Pittsburgh requires a Short-Term Rental License ($175/year) from the Bureau of Building Inspection. A property inspection is required before the license is issued. Occupancy is limited to 2 persons per bedroom and you must provide a 24/7 responsible party contact. Pennsylvania's 6% Hotel Occupancy Tax plus Allegheny County's hotel tax apply — STR platforms handle tax collection.
Is my Pittsburgh property at risk for landslides?
Potentially, depending on your neighborhood. Pittsburgh's steep hillsides in Mt. Washington, Duquesne Heights, Knoxville, and similar areas have known landslide risk. The Pennsylvania Geological Survey and Allegheny County maintain slope stability maps. For new construction on steep slopes (over 15% grade), a geotechnical study is typically required by Pittsburgh's Department of City Planning. Hillside development regulations (Pittsburgh Zoning Code Chapter 902) govern construction on slopes.
How do historic district rules affect my Pittsburgh home?
Pittsburgh has 14 local historic districts, including Mexican War Streets, Allegheny West, and parts of Lawrenceville and Shadyside. If your home is a contributing structure in a Pittsburgh Historic Review Commission (PHRC) district, exterior changes require a Certificate of Appropriateness before a building permit is issued. Interior changes don't require PHRC review. The PHRC reviews windows, doors, siding, roofing materials, and additions for compatibility with historic character.
What should I know about permits for Pittsburgh's older housing stock?
Pittsburgh's housing stock is notably older — many homes date to the early 20th century or late 19th century. Pre-1978 homes have lead paint — lead paint disclosure required for renovation. Pre-1980 structures require asbestos surveys before demolition. Pittsburgh's older homes may have knob-and-tube wiring, cast iron plumbing, and masonry construction that require specialized contractors familiar with historic rehabilitation techniques.
Does Pittsburgh allow solar panels?
Yes — Pittsburgh allows solar installations with an electrical permit from PLI. Duquesne Light interconnection is required for grid-tied systems and Pennsylvania's net metering law requires utility credits for excess generation. Pittsburgh's hilly topography means solar potential varies significantly by property — south-facing slopes have excellent exposure while north-facing or heavily shaded lots may have limited viability. Historic districts have additional review requirements.
Source: Pittsburgh Permits, Licenses, and Inspections (PLI) — Building Regulations. Last verified April 6, 2026. View source