ADU Rules in Pittsburgh, PA (2026)
ADU rules, permit requirements, size limits, and fees for Pittsburgh, PA. Source-cited from official municipal code.
Yes, ADUs are allowed in Pittsburgh, PA.
Pittsburgh, PA permits accessory dwelling units (ADUs) on residential properties. ADUs — also called granny flats, in-law units, backyard cottages, or secondary suites — are secondary housing units on a single-family or multifamily lot. State and local law governs the approval process. In Pittsburgh, the Pittsburgh Permits, Licenses, and Inspections (PLI) handles ADU permit applications. Below you will find the current size limits, setbacks, fees, and timeline for building an ADU in Pittsburgh.
ADU Size Limits
ADU Size Limits in Pittsburgh: Detached ADU: up to 800 sq ft (max height: 20 feet). Attached ADU: 30% of primary dwelling floor area. Pittsburgh allows accessory dwelling units up to 800 sqft detached. JADU is a California-specific concept — not applicable in Pittsburgh.
| Type | Max Size | Max Height |
|---|---|---|
| Detached ADU | 800 sq ft | 20 feet |
| Attached ADU | 30% of primary dwelling floor area | Per zone height limit |
Permit Fees
ADU Permit Fees in Pittsburgh: Plan check fee: $200–$800. Building permit fee: Based on construction value — typically $800–$3,000. Impact fees: None. School fees: None or N/A. Total estimated permit cost: $1,500–$5,000 total permit fees. Pittsburgh does not charge development impact fees for residential ADU scale projects. Permit fees based on project valuation.
| Fee Type | Amount |
|---|---|
| Plan Check | $200–$800 |
| Building Permit | Based on construction value — typically $800–$3,000 |
| Impact Fees | None |
| School Fees | None |
| Total Estimate | $1,500–$5,000 total permit fees |
Permit Timeline
Pittsburgh ADU Permit Timeline: Pittsburgh DCP building permit: typically 4-8 weeks. Pittsburgh Permits, Licenses, and Inspections (PLI) handles building permits. Construction 3-9 months. Apply through the Pittsburgh Permits, Licenses, and Inspections (PLI) online permit portal. Phone: (412) 255-2175.
Setback Requirements
ADU Setback Requirements in Pittsburgh: Front setback: follows zone standard. Side setback: 3 feet. Rear setback: 5 feet. Pittsburgh minimum accessory structure setbacks: 5 ft rear, 3 ft side. Pittsburgh's narrow lot widths in row house neighborhoods create practical constraints. Many Pittsburgh lots are long and narrow — ADUs typically placed in rear yards.
Parking Requirements
Parking Requirements: No additional parking required for ADU in most Pittsburgh residential zones. Pittsburgh's urban density and transit access support parking-free ADU policy.
Restrictions & Requirements
- ADU must be located in rear or side yard — not forward of primary structure
- Lot must meet minimum size for the applicable zone
- Only one accessory dwelling unit per lot
- Cannot be separately conveyed from primary lot
- Must maintain lot coverage limits
- ADU must have independent access
How Many ADUs Are Allowed?
Number of ADUs Allowed in Pittsburgh: Single-family lots: 1. Multifamily properties: Additional units in R2 through R6 and RM zones per development standards. One ADU per single-family lot. Pittsburgh's housing policy has been increasingly supportive of additional density to address affordability.
Single-Family Lots
1
Multifamily Properties
Additional units in R2 through R6 and RM zones per development standards
Historic District Considerations
Historic District Requirements: Pittsburgh has 14 historic districts where additional design review may be required for ADU construction. Design review approval is required before obtaining a building permit for properties in historic overlay zones. Pittsburgh has a rich industrial and architectural heritage with multiple National Register Historic Districts and locally designated historic districts. Key districts include Mexican War Streets, Allegheny West (North Side), Downtown Cultural District, Homewood-Brushton, and portions of Shadyside and Squirrel Hill. Pittsburgh Historic Review Commission (PHRC) reviews exterior alterations to contributing structures in local historic districts. Carnegie, Frick, and Heinz institutional buildings add architectural significance. Carrie Blast Furnaces and other industrial heritage sites are regionally significant. Look up historic district boundaries at: https://pittsburghpa.gov/dcp/historic
Frequently Asked Questions
Can I build an ADU in Pittsburgh?
Yes. Pittsburgh, PA allows accessory dwelling units. On a single-family lot you can build 1.
How big can an ADU be in Pittsburgh?
The maximum size for a detached ADU in Pittsburgh is 800 square feet.
How long does it take to get an ADU permit in Pittsburgh?
The typical ADU permit timeline in Pittsburgh is Pittsburgh DCP building permit: typically 4-8 weeks. Pittsburgh Permits, Licenses, and Inspections (PLI) handles building permits. Construction 3-9 months.. Total estimated permit fees are $1,500–$5,000 total permit fees.
Do I need extra parking for an ADU in Pittsburgh?
No, Pittsburgh does not require additional parking for ADUs.
Do I have to live on-site to have an ADU in Pittsburgh?
No, owner-occupancy is not required for ADUs in Pittsburgh.
Source: Pittsburgh Code of Ordinances Title 9, Article 1 — Zoning; PLI Permit Division. Last verified April 6, 2026. View source