The Philadelphia Historical Commission, concerned about a potential collapse, Friday approved demolition and reconstruction of the crumbling east side of the Spring Garden house once owned by abolitionist Robert Purvis.

Last month, a commission panel recommended denial of the project, arguing that the developer's plans were vague and that the engineering drawings were out of date. Preservationists attending that hearing also expressed concerns about the owner's financial resources.

The developer, Miguel Santiago, whose family has owned the corner rowhouse at 1601 Mount Vernon St. since the 1970s, insisted he had the financing to proceed. Santiago says he intends to renovate the building into three condo units.

The commission has looked at plans for the property several times in the last 10 years and Santiago has been cited for serious code violations by the Department of Licenses and Inspections.

Most recently, he has been ordered by Common Pleas Court Judge Bradley K. Moss to complete all repairs by June 7. Moss has already fined Santiago $10,000, with additional fines possible if building-code violations are not remedied.

Of particular concern is the rear section of the east wall, which has suffered serious water damage over the years. Windows have been open and interior floors and joists are deteriorating. Santiago has installed a new roof and braced the wall. Window openings have been intermittently covered. Brick and mortar are disintegrating.

Santiago told commission Chairman Sam Sherman Jr. on Friday that no contracts had been signed, but that he hoped to begin "as soon as possible."

"I've talked to different contractors," he said, but allowed that he had no firm timeline.

Sherman expressed concern that once work began, some "catastrophic scenario" might develop that would lead to the building's collapse. Santiago assured him that "the wall is braced."

The 1859 three-story house, purchased by Santiago's father, who ran a dry-cleaning business out of the first floor, is of considerable historic significance because of the fame of its former owner.

Purvis, who bought the house in 1875 and lived there until his death in 1898, was founder of the American Anti-Slavery Society and the Philadelphia Vigilant Association. He was a close associate of abolitionist William Still and assisted, according to his own records, 9,000 men and women in escaping slave owners.

The Mount Vernon Street house is the only surviving building associated with Purvis, often called the president of the Underground Railroad.

Santiago has said he was "definitely interested" in the "historic value and purpose" of the house, although Friday he expressed frustration with court fines.

In the end, given monitoring by the courts and L&I, commission members decided to approve Santiago's plans on the condition that he provide updated, accurate drawings, and work closely with the commission's staff as the project unfolded.

"I don't think it's in the interest to have this thing drag on through the summer with no activity," Sherman said.

Contact culture writer Stephan Salisbury at 215-854-5594 or ssalisbury@phillynews.com.