Changing Skyline: Developers in the city - Hard to hold 'em down

America is slouching toward recession, and suburban home builders are in a time-out, but in Philadelphia developers are still dreaming big dreams. Indeed, the size of those dreams keeps growing bigger.

In Society Hill and Spruce Hill, two neighborhoods renowned for their low-rise architectural cohesion, developers are aggressively seeking approvals for new projects that would seriously bust the local height limits. It's as if no one told these builders about the mortgage-lending crisis.

From a big-picture perspective, there's some comfort in their proposals. Developers wouldn't be talking about more tall buildings unless they felt confident that Philadelphia could weather the coming economic storm. The projects, which combine hotels with other uses, also suggest that the downtown construction boom of the last few years isn't a passing fad, but part of a deeper commitment to cities and urban life.

Try telling that to residents who have nurtured their enclaves through decades of hard times. They can't help but worry that the multistory arrivistes will destroy the very qualities that now make their neighborhoods desirable - cozy tree-lined streets, houses that wear time's patina, modest commercial buildings. If developers insist on intruding, they argue, why can't they just build more of the same?

The answer is as simple and complicated as the price of land. The decade-long building boom dramatically altered the city's construction paradigm. Downtown land, once cheap enough to squander on surface parking lots, is suddenly valuable, as evidenced by the recent sale of a Rittenhouse Square acre for $37 million. Such prices demand height and density for developers to recoup their costs.

So in a city built rowhouse by rowhouse, the tall building is becoming, by default, the new norm, not just in Center City but also in the ring of surrounding neighborhoods. As James Templeton, the architect for Society Hill's proposed Stamper Square, bluntly put it: "You're not going to see rowhouses built downtown in large numbers ever, ever again."

If that's the case, how does a city famed for its gentle, historic neighborhoods respond?