With more federal buildings per block than any other U.S. metropolitan area, Washington, D.C., has become the recognized leader in “green” architecture, and for its role in the revival and preservation of the city’s historic properties.
In March, the District of Columbia was recognized by the U.S. Green Building Council (USGBC) for leading the nation with the most commercial and institutional buildings per capita to have achieved Leadership in Energy & Environmental Design (LEED) certification. Using U.S. 2010 Census data, the USGBC determined that the District of Columbia had 25 square feet of LEED-certified space per person in 2010, which was more than double the square footage for runner-up Nevada.
A USGBC spokesperson told the Chicago Tribune that Washington’s emphasis on LEED certification is being driven by the federal stimulus program, which is funding the construction and renovation of many government-owned buildings. The spokesperson noted that U.S. General Services Administration, which manages government property and records, requires all new construction and renovation projects to achieve LEED certification. The District currently has approximately 650 buildings registered for LEED certification, the Tribune reported.
Washington has also evolved into a central player in the preservation movement, according to an article in Washingtonian magazine. “The federal government owns many historic properties in the capital, it provides tax breaks for renovation, and the National Park Service is arbiter of the National Register of Historic Places, which lists 80,000 nationwide,” the magazine explained. “Many preservation groups, including the National Trust for Historic Preservation, are headquartered here, and the Mid-Atlantic region is a treasure trove of historic places, from Williamsburg to Fort McHenry. D.C.’s preservation law... is one of the strongest in the nation.”
Preservation is “part of building a city,” noted Shalom Baranes, who the Washington Business Journal described as one of the city’s leading local architects. Baranes and his staff have been involved with numerous commercial office renovations, including the 12-story, 308,579-square-foot structure at 1100 L. St., NW, where a two-coat masonry system from Tnemec was specified for exterior aggregate panels in the early 1990s. “Standard latex acrylic coatings that are typically used on these buildings don’t perform well,” Tnemec coating consultant Todd Guntner explained. “They tend to break down with the freeze-thaw cycling issues that you have in eastern Mid-Atlantic States. These buildings require a coating system that won’t crack, chip or peel under freeze-thaw conditions.”
The uncoated panels were power-washed with a biodegradable cleaner to address environmental concerns about run off, then primed with Series 151-1051 Elasto-Grip FC, a waterborne modified polyamine epoxy used for sealing masonry substrates. The topcoat was Series 156 Enviro-Crete, a flexible, breathable waterborne acrylate that offers excellent elastomeric protection against driving rain, alternate freezing-thawing and ultraviolet (UV) light. “The coating system looks great after all these years,” Guntner observed. “And these coatings are very low-VOC (volatile organic compound) products.”
Another Baranes renovation at M Street and Connecticut Avenue used the same coating system on uncoated aggregate panels that had become discolored over the years from window-washing chemicals and street pollution. “The building’s owner had tried power-washing the panels, but couldn’t remove the staining, so they coated them with Series 151 and Series 156,” Guntner noted.
Several other business offices have been renovated based on the success of these Baranes projects, Guntner added. The same system has also been used on masonry buildings where the substrate was previously painted. He cited the example of one commercial property located at I and 17th Streets, where a masonry substrate was coated 15 years earlier with an epoxy coating that was losing its color. After the coated substrate was power-washed with a biodegradable cleaner, it was primed and topcoated. In addition to sealing cementitious and other porous substrates, Series 151 is an excellent tie-coat over sound existing coatings.