Paul Boni, the attorney for the Society Hill Civic Association, one of the opponents of the high-rise, said that Monday's Commonwealth Court decision was "more deadly" to the project.
"I don't know if the developer redesigns the project, or just gives up, we hope," Boni said.
Neil Sklaroff, an attorney for Turchi, could not be reached for comment.
The 16-story development - or 17 stories, if counting the two floors of the penthouse separately - would retain about half of the Dilworth House and configure what remained into a lobby, office space, and maybe some added condo uses.
A key selling point for the project, besides its location, is that it would be designed by the world-renowned architectural firm of Venturi, Scott Brown & Associates.
The Dilworth House was built in 1957 and is considered historically significant because of Dilworth's decision to locate in the neighborhood, helping to stimulate a revival of then-declining Society Hill.
The Philadelphia Historical Commission approved the demolition, but the Board of Licenses and Inspections Review twice rejected the proposal.
Commonwealth Court reversed a variance granted to Turchi to build the tower without a loading dock. The project contains more than 90,000 square feet of space. The city's zoning code requires a loading dock for a building that is more than 50,000 square feet.
The Zoning Board of Adjustment, citing the limited space available for vehicle maneuvering and parking, decided that requiring a loading dock was a hardship for the developer. The appeals court ruled that the hardship was self-inflicted because the proposed building was so big.
The developer's "desire to expand the use of the subject property in order to maximize profitability is not a sufficient hardship to justify the grant of a variance," Judge Robert Simpson wrote in the court's opinion.
The appeals court also ordered the Zoning Board of Adjustment to hear various objections to the project that the board had refused to consider.
Contact Robert Moran at 215-854-5983 or firstname.lastname@example.org, or follow @RobertMoran215 on Twitter.