Greenberger, 56, a principal at MGA Partners Architects, has increasingly involved himself in the city's zoning and planning debates. He was one of the founders of the Design Advocacy Group, which has become the voice of the local design and planning community.

In a sense, Greenberger is both an outsider and an administration insider. During the recent mayoral campaign, he was part of a group at the Design Advocacy Group that lobbied hard to get its issues on the candidates' agendas. As a result, Nutter asked Greenberger to serve on his transition team, chairing the committee on zoning. He later appointed him vice chairman of the Planning Commission.

The mayor will introduce Greenberger today at a City Hall news conference.

"We're really pleased that Mayor Nutter adopted a lot of DAG's reform agenda, and this appointment caps it off," said Joanne Aitken, who became Design Advocacy Group chair after Greenberger stepped down this summer.

Greenberger takes over as executive director of the Planning Commission at a critical time. The city is in the midst of a major overhaul of its antiquated zoning code, a complex task that will take years. But the city planning staff was slashed during the Street and Rendell administrations.

John Gallery, a former city planner who heads the Preservation Alliance, said Greenberger's appointment was evidence the mayor "believes design matters." Because Greenberger is an architect, Gallery said, he will probably need to hire deputies experienced in the technical aspects of zoning.

"I certainly wish I had that expertise," Greenberger said yesterday. "But what the Planning Commission needs right now is not someone with technical expertise, but someone with leadership ability who can rally people around a new vision."

The Nutter administration did not initially consider Greenberger as a candidate for planning director. But after several promising applicants withdrew, Greenberger said he became concerned that the mayor would be unable to carry out his promised changes. He asked to be considered for the $155,000-a-year job after hearing Nutter's June policy address on planning.

"I do feel quite sincerely that this is one of those 50-year seminal moments in history of Philadelphia and not just another change of administration," Greenberger said.

Deputy Mayor Andrew Altman, who oversees planning and economic development, said yesterday 8/14 that Greenberger was a perfect fit for the job because his "combination of skills bridge both design and planning."

"He's someone who understands Philadelphia's great planning tradition and is inspired to bring the city back to that level," Altman said. "He's entrepreneurial. He [has] management experience, teaching experience at Penn. It's a home run."

A graduate of Rensselaer Polytechnic Institute, Greenberger came to Philadelphia in 1974 to work for Mitchell/Giurgola Architects, one of the leading local firms at the time. He later formed the spin-off known as MGA Partners. When he takes the city post, he will have to sever his connection to the firm and step down from the Planning Commission board.