Philadelphia was a different place in the early '80s when Andrew Altman left home to help mend America's wounded cities. In those days, William Penn still ruled over a flat-topped skyline from City Hall's tower. The streets around Rittenhouse Square emptied out at night. And the only use anyone imagined for North Philadelphia's great manufacturing lofts was as landfill.

So you'll have to understand if it takes the renowned urban planner time to get his bearings.

"What's the best way to get to the Four Seasons?" he pondered the other day as he stepped out of a hip cafe at 15th and Walnut Streets.

Just hired as Mayor Nutter's deputy mayor and commerce director, this hometown boy finds himself returning to a place he hardly recognizes. A self-described "neurotic" whose favorite pastime is exploring new cities, he says he's eager to reacquaint himself with the one where he was born, grew up (Germantown, Society Hill), and went to college (Temple).

"I've got to see what Northern Liberties is all about," he said.

Though his mother and many relatives remain deeply rooted here, Altman never expected to live in Philadelphia again. But drawn by the buzz surrounding the new administration, he impulsively inquired about employment in November.

Now Altman, 45, has a hefty job description that, for the first time, will integrate traditional city planning and economic development. He believes his dual role, which pays $185,000 a year, will allow him to get beyond "making pretty plans" and concentrate on comprehensive city-building, creating developments that provide places to live, work and play.

Altman's credentials are being touted as evidence that Nutter is serious about making planning important again, and ending years of seat-of-the-pants deal-making that marginalized the city's professional staff.

"It's a signal that the mayor wants to modernize and professionalize city government," said Gary Hack, dean of the University of Pennsylvania's School of Design.

Hack was Altman's professor at the Massachusetts Institute of Technology when the young planner was a graduate student. "He's exactly what Philadelphia needs" to restore credibility to the city's broken planning and zoning agencies, Hack said.

Though a booming Center City may feel strange to Altman, the new job is one he knows well.

He did planning and policy-making stints in Jerusalem, Los Angeles, Oakland and Washington. Arriving in Washington in 1999 as the city was emerging from bankruptcy, he was obliged to re-create the planning department almost from scratch. His efforts are credited with helping Mayor Anthony Williams ignite a development boom that has spread to the city's forgotten Anacostia waterfront.

"Andy and Mayor Williams reestablished confidence. They created a market," said Richard Bradley, who runs the capital's Downtown Business Improvement District. "The great thing about Andy is that he can do grand planning. But he would always think it through and ask, 'How do you make this happen?' "

There were times, however, when he was criticized for pushing too much. Residents in Washington's Mount Vernon Square, in particular, complained bitterly that he had foisted too much density on their neighborhood, although others praised the project for bringing thousands of new residents to a soulless stretch of Massachusetts Avenue.

Ultimately, Altman decided in 2005 that he was done with government work. He moved to New York, started a consulting firm, and settled happily in Manhattan's tony Tribeca section with his wife and two young children.

"I didn't want to be one of those planners who go from city to city," he explained. He also wanted to try his hand at private development, to prove he could convert a planner's vision into bricks and mortar.

"I wanted to figure out how things got implemented," said Altman, who did most of his work for Lubert-Adler, a major development firm in Philadelphia.

His mother, Linda Rubin, had other ideas.

For 20 years, she had been "subtly" telling her son that he ought to return to Philadelphia by peppering him with newspaper clippings about the city's development. It took Nutter's election and a new plan for the Delaware River to convince him that she was right.

Knowing that "Andy loves waterfronts," Rubin said, she persuade him to attend PennPraxis' final presentation of its waterfront plan in November.

"I left feeling so impressed by the spirit of 1,400 people in the room," Altman said. "It piqued my interest in coming back to Philly."

Two weeks later, he returned to hear Nutter address The Inquirer's Great Expectations Citizens Convention. That clinched it.

"I wouldn't be here but for the mayor of Philadelphia. I was so overwhelmed by his speech," Altman said. "Other cities had called, and I said, 'No.' But there are moments in the history of cities when transformation is possible. This is one of them, and I wanted to be part of that."

He was further convinced after he interviewed with Nutter on a high floor in the Centre Square complex, across from City Hall. Nutter led Altman to a window, where they gazed past the glittering downtown towers at the expanse of struggling rowhouse neighborhoods and Philadelphia's two underdeveloped rivers. "Nutter talked about the city with great passion," Altman recalled.

Like Nutter, Altman attended a smorgasbord of public and private schools in various neighborhoods, and got to know different parts of the city. As a teenager, Germantown's Chelten Avenue was his stomping ground. While at Temple, he worked as a security guard at the Spectrum.

Altman acknowledged that transforming a politically unruly, blue-collar city like Philadelphia won't be easy. Unlike Washington, it can't rely on the federal government to guarantee jobs in good times and bad. Nor is Philadelphia a hot market, like Washington, where national companies beg for a chance to build.

Development patterns are different, too. Because Washington has a strict height limit, there's no wrestling with developers over their demands for ever-taller skyscrapers, as Philadelphia does regularly.

And, as Altman modestly conceded, "I'm just learning about councilmanic prerogative," the tradition of allowing City Council members to dictate big zoning decisions in their districts.

He has high hopes of taming the various interests. Because his position as deputy mayor gives him control over other departments related to planning - including commerce, zoning, historic preservation, and licenses and inspections - Altman argued that he has the power to pull all the pieces together. He intends to hire a director to oversee the day-to-day business of the Planning Department.

Having worked with Williams, who righted Washington after the disastrous reign of Marion Barry, Altman understands that a mayor's leadership will be crucial.

In Washington, "the entire government knew that planning was the mayor's thing. That was powerful," Altman said. "Williams believed that city planning is about identifying the soul of the city. It isn't just the dry machinery of getting a project done as fast as possible."

Williams made it clear that developing the Anacostia waterfront was a key to reviving the capital's impoverished neighborhoods. By repeatedly articulating that agenda, Altman said, the mayor gave him a mandate.

The waterfront was such an important part of his work that Altman became the first chief executive of the Anacostia Waterfront Corp., laying the groundwork for a new ballpark that will open this year.

Nutter has also talked about the riverfront as a "huge opportunity," Altman said. "He told me about all the failed plans and said now is the time to get it done."

But, he said, he also expects to focus on neighborhoods bypassed by the recent development boom.

"When you take the train from New York, you see so much poverty. Then you come to this sparkling downtown. The contrasts are extreme," he said. As commerce director, he expects to use incentives and new infrastructure to attract investment to those needy places.

It's not as if Altman has any shortage of plans. He has wanted to be a city planner since he was 10 and read Edmund Bacon's landmark book, Design of Cities. It prompted him to draw up detailed schemes for Philadelphia.

"I still have them," he said.

Altman's Views on the City

On planning: "Urban development is as much about sales, believing in your vision, selling your vision. Planning has lost its sales aspect. It became too technocratic and too timid in the post-urban-renewal period."

On skyscrapers: "Height has a lot to do with context. Changes in scale, depending on how they're managed, can be interesting, but you need to be careful. What happens on the ground floor is what's really important. . . . New York planning director Amanda Burden is famous for grilling developers about their ground floors, the entrances, retail spaces, amenities. Now they come prepared."

On Philadelphia's strengths: "One of the greatest things Philadelphia has is its walkability. That's what other places are trying to create. . . . Philadelphia's centrality is its great competitive advantage. It has the transit. . . . Another great economic advantage is place - the public spaces, the vibrancy of the street. . . . The third is its workforce."

On economic development: "One of the things a commerce director needs to do is worry - and not just worry - about the economic base of the city. . . . You can't presume the city has unlimited growth potential. You must always be nurturing the major institutions, the meds and eds."

On waterfront casinos: "I'm going to have to wait and see on that one."