Riverside Plaza, a historic housing development in Minneapolis, was awarded the 2013 National Trust/HUD Secretary's Award for Excellence in Historic Preservation.

The award recognizes efforts that advance the nation's historic preservation goals while providing affordable housing and economic development opportunities for low- and moderate-income residents.

Riverside Plaza recently underwent a $90 million renovation led by Minneapolis-based Sherman Associates.

Built in 1973, the plaza is a complex of 15 buildings with residential and commercial space designed by noted architect Ralph Rapson. It was was intended to be the first phase of an urban community in the city's Cedar-Riverside neighborhood, but additional phases of the development were never built. The complex, one of the largest HUD-supported projects in the United States, encountered financial problems and fell into disrepair, HUD said in a news release.

The plaza earned National Historic Register status in 2010, clearing the way for Sherman Associates to use federal and state historic tax credits to help fund a two-year rehabilitation of the complex's apartments, public plaza, parking structure, and common areas.

Renovations included retrofitting windows and replacing HVAC equipment, water supply lines, and patio doors. Elevators were upgraded and a sprinkler fire-suppression system added. The building facades were also renovated to feature the complex's original "playful color scheme."

HUD said the rehabbed Riverside Plaza "will extend the life of the complex's 1,303 housing units, 90 percent of which are affordable to households earning less than 60 percent of area median income, for another 40 years."

Janet Moore covers commercial real estate for the Star Tribune.