Pennsylvania ADU bill clears House, heads to Senate

Pennsylvania Gov. Josh Shapiro declared he intended to go big on housing.

On Monday, at least one piece of that ambition cleared the state House with a bipartisan vote, setting up a tougher sell in the Republican-controlled Senate.

The House passed House Bill 2186, requiring municipalities statewide to allow one accessory dwelling unit per residential lot by right – no special exception or variance required. House Republicans crossed the aisle to support the measure, a notable showing for legislation that preempts local zoning authority.

Allowing ADUs by right has become a common tool in states grappling with housing affordability. California is the national model, and about 10 states have followed as lawmakers search for ways to add supply without large-scale new development.

Pennsylvania’s ADU bill is part of Shapiro’s sweeping housing agenda, unveiled in February, and is one of its few concrete legislative wins. The governor has advanced what he could through executive action, releasing the state’s first-ever Housing Action Plan and creating a deputy secretary for housing. Other zoning reform measures, including bills to expedite high-density approvals and modernize the Municipalities Planning Code, remain in committee.

Shapiro’s signature proposal – a $1 billion Critical Infrastructure Fund backed by state bonds – remains unresolved ahead of the June 30 budget deadline. He has also failed, for the third consecutive year, to secure funding for his Whole-Homes Repair program, which helps low-income residents stay in their homes. The Senate, meanwhile, passed only a resolution directing a study of the state’s 1968 Municipalities Planning Code.

The Republican-controlled Senate remains the obstacle. GOP leaders have called Shapiro’s $53.3 billion budget proposal irresponsible and vowed a leaner alternative. Whether the chamber takes up HB 2186 independently or folds it into budget negotiations could determine how much of his housing agenda survives the session.

Cutting red tape

Pennsylvania has no statewide ADU law, leaving rules entirely to individual localities. Red tape thwarts projects even in the few counties that allow ADUs, Mario Mascioli, owner of Pennsylvania-based Acorn Built Homes, told The Builder’s Daily.

“If we could get permitted quickly – no special exceptions, zoning hearing boards, variances, and the townships’ move, we could complete these things in six months instead of never being able to do it, or taking a year and a half to do,” Mascioli said.

He said cutting red tape would lower construction costs by roughly 30%. Mascioli pointed to Princeton, New Jersey, as a model for ADUs and a reason his company builds there.

“They have a very favorable ADU law, which is much like the laws in California, in some cases even better,” he said.

The House bill limits how far local governments could go in regulating size, setbacks, parking and design. Municipalities could still bar short-term rentals of fewer than 30 consecutive days. Deed restrictions and planned-community rules would remain in effect.

Politics matter

House Democrats, who hold a slim majority, could have passed the bill on their own. But it passed 139-62, pulling in a third of the 99 House Republicans.

Whether that bipartisan margin carries weight in the Senate remains to be seen. Republicans hold a 27-23 majority, and statewide zoning preemption has historically met resistance.

Local governments opposed to losing zoning power have tried to shape the debate. House Bill 2109, which would limit municipalities’ ability to cap the number of unrelated people living in a home, cleared the same committee as the ADU bill but has not come to a full House vote.

Before the April committee hearing, the Pennsylvania State Association of Township Supervisors warned in a Facebook post that HB 2109 would impose “statewide zoning mandates on townships.” The association also likened the bill to “Animal House,” the 1978 comedy film about a raucous college fraternity, arguing that loosening occupancy rules could undermine residential neighborhoods.

HB 2186’s passage in the House gives zoning reform advocates momentum heading into a budget season that ends on June 30. Whether it clears the Senate may determine how much of Shapiro’s housing agenda becomes law this year. Americans for Prosperity-Pennsylvania has been vocal in its support for the bill, and its influence in the GOP-controlled chamber could prove decisive.

“The state Senate has a critical opportunity to address Pennsylvania’s growing housing crisis and restore taxpayers’ property rights in one fell swoop,” said Emily Brey, AFP-PA’s state director, calling on lawmakers to support free-market reform. “Now is not the time to be on record opposing reforms aimed at lowering the cost of living.”