ADU Laws in Pennsylvania (2026)
Pennsylvania state ADU law details, key provisions, preemption status, and recent legislative changes for accessory dwelling units.
Law Name
State ADU Law
Preempts Local Ordinances
No — local rules may be stricter
Has State Law
Yes
Key Provisions
Pennsylvania does not have a statewide ADU law as of 2026
ADU regulation is left to local municipalities under the Pennsylvania Municipalities Planning Code (MPC)
Philadelphia, Pittsburgh, and other PA municipalities set their own ADU ordinances
Pennsylvania MPC (Act 247) gives municipalities broad authority over zoning and land use
Philadelphia has enacted ADU provisions through local zoning code amendments
Pennsylvania Housing Finance Agency provides resources on affordable housing but no statewide ADU mandate exists
Official Sources
Source: Pennsylvania State ADU Law. Last verified April 5, 2026. View source