The Philadelphia Historical Commission, which has been under fire from critics who say it is too quick to allow hardship demolitions of certified landmarks, is fighting back in an unusual way: It wants to change the rules to make it tougher to overturn those demolitions on appeal.

Commission Director Jon Farnham said the proposed rule changes were prompted by several recent bruising legal battles. Those cases, he said, led him to conclude that the commission needed to clarify ambiguous language to protect the city from drawn-out and frivolous appeals.

A discussion of the revised rules had been scheduled for Friday, but has been pushed back to April 12. The commission will have to hold a hearing before the new rule could be adopted.

The proposal has set off alarm bells in Philadelphia's preservation community, which is appealing demolition approvals for the Church of the Assumption and three landmarked houses in West Philadelphia. On Wednesday, the Preservation Alliance issued an "advocacy alert" to its members, and called on the commission to delay action so the measure could be studied more thoroughly.

Benjamin Leech, who runs the Alliance's advocacy programs, said he first learned about the proposed rule change Friday when Farnham sent an e-mail with the revised wording. It was accompanied by a five-page legal analysis explaining why the hardship wording needed to be amended.

The commission decided to postpone the discussion because its chairman would be unable to attend Friday's meeting, said Alan Greenberger, the city commerce director, in a joint interview with Farnham.

Hardship has always been a difficult area of preservation law. Once buildings are listed on the city's historic register, they cannot legally be torn down unless the owner can prove that maintaining a structure would be an unreasonable financial burden, or hardship.

To show hardship, the current rules require owners to prove there is no possible, economically feasible use for the building. As part of the proof, "the applicant has an affirmative obligation in good faith to attempt the sale of the property."

The new wording would broaden the meaning of that clause. Instead of being required to hire a broker and list a historic building for sale, the owner would only have to "demonstrate the sale of the property is impracticable" under current market conditions.

Andrew Palewski, a preservation consultant who is leading the fight to save the Church of the Assumption at 12th and Spring Garden Streets, criticized the wording and said it appeared to be an attempt "to make the rules more ambiguous."

Andrew Ross, the city solicitor who represents the commission, insisted the change was to make sure the wording in the regulation is the same as in the wording in the ordinance that created the commission. "We're just copying language from the ordinance," he said.

That made no sense to Paul Boni, the lawyer challenging the commission's decision to grant hardship to the University of Pennsylvania, which is seeking to tear down a mansion by Samuel Sloan at 40th and Pine Streets.

"The whole purpose of having rules and regulations is to fill in the gaps and elaborate on the ordinance," Boni said. "If all you're going to do is parrot the ordinance, there is no need for rules."

In the past, Farnham has described hardship as an "escape valve" that makes the city's preservation laws work. Without it, he said, owners could argue that preservation laws amounted to an unconstitutional seizure of property.

Contact Inga Saffron at, 215-854-2213 or on Twitter @ingasaffron.