An article in the May 17 Washington Business section incorrectly identified an environmentally friendly apartment complex in Silver Spring. The complex is Blair Towns, not Blair Towers. (Published 5/19/04)

The 12-story office building under construction at 500 New Jersey Ave. NW, three blocks from the Capitol, is a narrow building with special glass that keeps it warmer in the winter and cooler in the summer. It flushes in fresh air and the lights go on or off automatically depending on the amount of sunlight.

When the 133,000-square-foot building opens this fall as the new Washington office of the National Association of Realtors, a Chicago-based trade group with 1.5 million members, it will be the first LEED-certified office building built from scratch in downtown Washington, say developers and the U.S. Green Building Council, a nonprofit group promoting environmentally sound buildings. LEED stands for Leadership in Energy and Environmental Design. Environmental groups say it is an accurate measure and not just another marketing tool for developers.

"We wanted to make a statement that Realtors do care about the environment," said Lucien Salvant, an NAR spokesman. The group will move from its offices at 700 11th St. NW and take up 40,000 square feet in its new building, leasing the rest to another tenant.

The association is not entirely altruistic: It hopes the chance to save on utility bills in its building will lure in tenants. In fact, it bet an extra $2 million on the building's $44 million construction costs.

But some brokers are not so sure the NAR will get the $38.50 a square foot it is asking, which is less than the going rate of almost $40 a square foot for D.C. office space, given the number of office buildings going coming up in the District.

The association's building is part of a decade-long trend in Washington and across the nation. A LEED building typically has features like well-insulated windows, extra-efficient heating and air-conditioning units, and rooftops that collect rainwater so it can be used to water the landscaping around the building.

There are 105 LEED buildings, most in California; Portland, Ore.; New York; and Pittsburgh, the Green Building Council said. In the District, the National Geographic headquarters at 1145 17th St. NW has the LEED label. Maryland has two, the 78-apartment Blair Towers in Silver Spring and the headquarters of the Chesapeake Bay Foundation in Annapolis. In Virginia, the Pentagon Metro stop is LEED-certified for the landscaping it has put in to minimize the effect of surrounding concrete.

Most of the LEED buildings have been built for large tenants that have already committed to the space; only recently have developers started to build on speculation that tenants will want to lease the buildings. And so far, their track record is not so hot.

Tower Cos., a Bethesda-based office, residential and retail developer, built an office tower with a few environmental features in 1999 in Rockville near Interstate 270. Because of competition, it had a tough time leasing the site. It took two years for Tower to get Charlotte-based Bank of America Corp. as its largest tenant, Tower partner Jeffrey S. Abramson. said.

Asking rates for rent at the building have dropped from a high of $33 a square foot in 2000 to less than $32, according to real estate researcher CoStar Group. The bank's workers, though, said they like the large windows that allow for natural light and the feel of the fresh air pumped into the building.

"We weren't seeking out a green building, but I've found that when you work 60 hours a week, the space is comfortable," said Rick Schmidt, a senior vice president. "It's climate-controlled and gets a fair amount of afternoon sun. And the air quality is great."

Tower said it expects to soon start building a 285,000-square-foot building next door with LEED features and without a major tenant signed up. It opens in 2007.

Builders started trying to be energy-efficient in the 1970s, when simpler fixtures such as timers on lights and thick glass to keep out the cold were considered eco-friendly. When the Green Building Council started almost five years ago, it set industry-wide standards to help prevent developers from spuriously claiming their buildings were eco-friendly.

"Having the Building Council determine and rank what is green buildings has helped take it out of the earthy, crunchy alternative image and brings it into the mainstream," said Iris Amdur, a principal at GreenShape, a D.C. company that advises developers how to build green buildings. Her company is helping to design the NAR building.

Some developers say they are starting to put more environmentally friendly features in their buildings because they have realized the materials actually cost only 2 percent to 10 percent more on larger office buildings. And at least in theory they can lease the building more easily on the premise their tenants use less energy and get lower utility bills.

A larger developer such as Hines Development Corp. of Houston spends about $3 a square foot to put in items like filters to collect pollution before it goes through the air system and cost-saving energy transformers. "It can be a hard sale to explain that tenants will save on their energy bill in the long run, but that it may cost upfront," said Jerry Lea, a senior vice president at Hines. "But if a tenant understands what you're trying to do, they are willing to pay for that."

A rendering shows the new energy-efficient Washington office building for the National Association of Realtors.