High-Level Debate On Future of D.C.

Those regulations stood largely unchanged until 1894, when the Cairo, on a street lined with rowhouses, exceeded by 40 feet the tallest building at the time, the 120-foot Washington Loan and Trust on Ninth Street NW. "There was a public outcry, people complaining, though it was very civilized -- this was Washington, after all," Maloney said.

The Cairo prompted the District and eventually Congress to issue a series of regulations, culminating in the 1910 law: No building could be more than 20 feet taller than the distance between buildings across a street or avenue. On some parts of Pennsylvania Avenue, it allowed for 160-foot-high buildings. Although occasional challenges have cropped up, the law has remained intact, even as towers grew across the Potomac River in Rosslyn.

Philadelphia had a similarly sweeping, albeit informal, restriction that barred buildings from rising above the hat of the William Penn statue atop City Hall, 548 feet high. In the mid-1980s, a developer persuaded city leaders to allow a 60-story tower, which led to waves of additional skyscrapers.

Witold Rybczynski, an architecture critic who teaches at the University of Pennsylvania's Wharton School, said Philadelphia's new skyline took away what distinguished it from other cities, a fate that could befall Washington if its limits were changed.

"It would be a shame if Washington became like everywhere else," he said. "It seems to me that we could have one city that was very different."

The chances of overturning Washington's law appear slim, at least for the time being. It would require support not only from D.C. leaders but also from members of Congress, who have expressed opposition to raising the limit in the past. "I don't see this changing anytime soon," Gallagher said.

Leinberger, a Philadelphia native who lives in Dupont Circle, says he will leave the politics to others. His primary concern, he said, is presenting ideas for how the District can maximize its potential as an alternative to suburbia.

Standing at Dupont Circle one morning, he gazed at the vista of low-lying modern buildings and said they could each be significantly higher without compromising the area's architectural beauty.

How high?

No limit, he said, adding that the market should dictate. The prospect of lost sunlight did not bother him.

"There are trade-offs," he said. "The decision might be made to maintain the limit, but people should know the costs."