PARIS — Hard by the noisy highway, overlooking a cemetery and a former garbage dump, La Tour Bois-le-Prêtre glimmers on a spring morning. Sheathed in a fresh cloak of glass balconies and corrugated aluminum panels, it rises on the edge of this city amid a landscape of decaying cement-and-brick housing blocks.

This half-century-old tower used to be one of those blocks. Its makeover, by a creative team of local architects — Frédéric Druot, Anne Lacaton and Jean-Philippe Vassal — is a case study in architectural ingenuity and civic rejuvenation. It’s a challenge to urban innovators, too. Instead of replacing the old tower with an entirely new building, the designers saw what was worthwhile about the existing architecture and added to it.

Retrofitting, it’s called. Preservationists in America have argued for a long time about the benefits of reusing obsolete structures. Since some 80 percent of what’s been built in the United States has been constructed during the last 50 years, reuse seems like the inevitable wave of the future. The practice is not common when it comes to large public housing projects. But there have been a few successful attempts. This one is the latest.

Poor neighborhoods on the outskirts of Paris and in the city’s inner-ring suburbs are, as in many cities, dominated by these much-maligned projects from the 1960s and ’70s. Not long ago I visited Sevran, one of the poorest Paris suburbs, where the rioting that spread across France in 2005 started. Unemployment now hovers around 40 percent among the young there. Violence has gone up in the last couple of years. There was a shooting not long ago in a kindergarten.