ADU Rules in Pennsylvania (2026)
ADU rules in Pennsylvania — no statewide ADU law. Regulation is entirely local. Key provisions and city-specific frameworks for accessory dwelling units.
Law Name
Preempts Local Ordinances
No — local rules may be stricter
Has State Law
No — regulation is local
Statewide Preemption Status Unconfirmed
No statewide preemption statute was confirmed for this jurisdiction — regulation is local. Local governments retain full authority to set their own rules.
Local Control Framework
Pennsylvania does not have a statewide ADU law as of 2026 · Source
ADU regulation is left to local municipalities under the Pennsylvania Municipalities Planning Code (MPC) · Source
Philadelphia, Pittsburgh, and other PA municipalities set their own ADU ordinances · Source
Pennsylvania MPC (Act 247) gives municipalities broad authority over zoning and land use · Source
Philadelphia has enacted ADU provisions through local zoning code amendments · Source
Pennsylvania Housing Finance Agency provides resources on affordable housing but no statewide ADU mandate exists · Source
Source: Pennsylvania Local Zoning Authority. Last verified April 5, 2026. View source