Broad Top

Pennsylvania has NOT enacted a statewide ADU preemption law. Under the Pennsylvania Municipalities Planning Code (Act 247 of 1968, 53 P.S. §§10101 et seq.), local governments retain broad authority over zoning, including ADU permission, setbacks, parking, size limits, and owner-occupancy. ADU rules vary widely by township, borough, city, and county. One active bill in the 2025-2026 session, HB 2186 (chief sponsor Rep. John Inglis), would amend Title 53 of the Consolidated Statutes to provide for ADUs, but was laid on the table on 2026-04-13 after a Housing and Community Development Committee vote (reported as 19 yes, 7 no during committee action) and has not advanced to third consideration.

Pennsylvania does not operate an ADU-specific statewide loan, grant, or forgivable-loan program. The Pennsylvania Housing Finance Agency (PHFA) administers general first-time-homebuyer, down-payment-assistance, and purchase-plus-improvement programs that can apply to properties with ADUs when eligibility criteria are met, but none target ADU construction as a distinct product. Notably, PHFA's HFA Preferred conventional product explicitly excludes two-unit properties, which can complicate financing an owner-occupied primary home that has (or plans to add) an attached ADU depending on how the appraiser and investor classify the unit.

• Pennsylvania Housing Finance Agency (PHFA)
• Keystone Home Loan / HFA Preferred
• Keystone Flex Purchase & Improvement with K-FIT
• Pennsylvania Homeowner Assistance Fund (PAHAF)

Pennsylvania does not run a state-level pre-approved-ADU-plan catalog, statewide impact-fee-waiver statute for ADUs, or streamlined-review mandate. State-level programs that touch ADU-adjacent policy are primarily coordinated through the Department of Community and Economic Development (DCED) and PHFA, and act by funding or assisting local jurisdictions rather than by preemption. Local ADU momentum — Pittsburgh's by-right ADU ordinance in designated zones and Philadelphia's 2020 zoning-code ADU provisions — is authorized under municipal authority granted by the Municipalities Planning Code (Act 247 of 1968), not by state mandate.

• Keystone Communities Program — DCED program that provides planning, design, and construction funding to municipalities for downtown revitalization, elm-street neighborhood improvement, facade grants, and blight remediation. Not ADU-specific. Participating municipalities can direct Keystone Communities funds toward housing-rehab and missing-middle projects where local policy supports ADUs.
• Pennsylvania Land Use Planning Assistance (PALUPA) / DCED Land Use Planning Technical Assistance — DCED and associated local-government-services staff provide model-ordinance drafting, zoning-code review, and planning technical assistance to municipalities interested in modernizing zoning (including ADU permission). Acts through local adoption rather than state preemption.
• Pennsylvania Municipalities Planning Code (Act 247 of 1968) Model-Ordinance Guidance — The DCED-published Pennsylvania Municipalities Planning Code PDF and companion Planning Series documents include model language municipalities can adopt, including for accessory uses, home occupations, and mixed-use areas. Not a statewide ADU mandate; a guidance and boilerplate library that municipalities may or may not adopt.