Mayor Nutter elevated the oft-overlooked matter of city planning to the top of his agenda yesterday, sending an unmistakable message to builders, civic associations and City Hall that he wants an abrupt end to Philadelphia's decades-old practice of ad hoc development.

"As a city government we now reject the 'let's make a deal' mentality that pervaded Philadelphia for much too long. Monty Hall has left City Hall. Those days are over," Nutter said in his address to an overflow crowd of hundreds at the Academy of Natural Sciences.

Nutter said he wanted urban design in Philadelphia to be guided by what he called "self-evident" values, such as the need to preserve the historic nature and character of the neighborhoods, a pedestrian-focused urban form that would not be trumped by the design demands of cars, and a love of parks and open space.

Nutter was emphatic about who would lead his proposed overhaul: the City Planning Commission, a once-powerful entity that has lost so much clout over the years that many big developers bypass it or give it only a token say in their projects.

Instead, it has been district City Council members, influential civic associations, and the Zoning Board of Adjustment that have acted as de facto planners for the city. The mayor clearly feels the patchwork system has worked poorly, suggesting that residents suspect it is rigged to benefit powerful developers, while builders complain the system is confusing, unpredictable and overly political.

"Over the years, for reasons of expediency both political and economic, we've strayed from relying on the Planning Commission as the arbiter of planning expertise," Nutter said.

"Tonight I want to make it crystal clear that the Philadelphia City Planning Commission is the city authority on planning and shaping the development of Philadelphia. They are the authority now in this city."

To that end:

Nutter said he would work with Council to pass legislation that would grant more authority to the Planning Commission. He did not offer specifics, but his intent is to give the largely advisory agency some teeth.

He instructed the commission not to approve projects before considering a transit and transportation study that "sets out the pros and cons" of the development in question.

The mayor directed the commission to create a Design Review Advisory Board, which would review major developments on aesthetic grounds. "Design matters. It is not a luxury," Nutter said.

Finally, the mayor told the commission its expertise was needed on a host of major development plans, such as those of local colleges and universities and Philadelphia International Airport, and taking the lead in creating a "practical framework" for Delaware River waterfront development based on the PennPraxis proposal to extend the street grid to the water's edge.

Nutter's remarks were met with guarded optimism by planning professionals in the crowd. They liked and appreciated what Nutter said, but the city's long track record of paying little heed to planning remained fresh in their minds.

Others, though, were elated by Nutter's address.

"The days when we had Ed Bacon and district Council people were afraid to challenge him are coming back," said at-large Councilman Bill Green, referring to the renowned urban planner who served as the Planning Commission's executive director for more than 20 years.