How to honor the layers of history and express the culture of today.

This spring marks the 50th anniversary of the law that created New York City's Landmarks Preservation Commission. It is not the oldest such law in the country'cities like Charleston, Baltimore, and New Orleans had protections against the destruction of historic property much earlier'but New York's is considered a national model because it is so comprehensive, according to Andrew Dolkart, professor of preservation at Columbia University's Graduate School of Architecture, Planning and Preservation. The statute is broad'it can be applied to single buildings, interiors, or entire neighborhoods. And its definition of places that are architecturally, historically, and culturally significant, says Dolkart, is 'deliberately vague. The built-in flexibility has made the law successful.'

When New York finally passed its landmarks law in 1965, it was not in direct response to the demolition of McKim, Mead, and White's Penn Station that had begun two years earlier, as is widely believed. The real catalyst was the sneaky razing of the Brokaw houses on the corner of Fifth Avenue and 79th Street'an extravagant mansion in the French Renaissance style, designed by Rose & Stone and built in 1888 by Isaac Vail Brokaw, along with three adjoining townhouses he built for his children. As protests mounted over plans to demolish the houses'while a landmarks law languished in the city council'the real-estate developer who'd bought the properties tore them down over a weekend in February 1965. The landmarks law passed that April, too late to save them. Later the law stood up to review by the U.S. Supreme Court in the successful but highly contentious fight to save Grand Central Station.

In New York, a building can be considered for landmark status after just 30 years (the federal standard is 50), and it's fascinating to note how ideas of architectural significance keep shifting. The early commissioners didn't think to landmark Art Deco structures like Rockefeller Center (1930'33) or the Empire State Building (1931), says Dolkart, and they would have been stunned to look into the future and see that the Seagram Building (1958) and Lever House (1952) would be landmarked by later commissioners as soon as they were eligible.

In this issue of RECORD, we look at contemporary interventions in historic structures around the world, from the careful restoration of an early seaside tearoom by 'lvaro Siza and the witty conversion of an indoor swimming pool in Tokyo into an event/retail space to the adaptation of an early 20th-century Catholic-school complex in Singapore into the National Design Center.

What is clear in these projects is that history never stands still. Even Siza's own faithful restoration of his tearoom cannot re-create the casual beach culture of the 1960s that his charming structure once served'it is now a high-end restaurant with a big-name chef'while the other adaptations respect and reveal their origins as they incorporate major contemporary design elements.

Adaptive reuse of structures that are historically important'or just plain old'is a major force in today's construction market (and a key means of building sustainably). For architects working on such projects, it is often a delicate balancing act. Just as vibrant cities evolve by reflecting the textured layers of history while continuing to build anew, so do many great structures stand the test of time by adapting to changed uses that honor the past but honestly express contemporary culture. 'The past lives only as part of the present,' wrote the late critic Ada Louise Huxtable, discussing how preservation should be pursued. 'The results will never be perfect, but they will be real.'