The Arlington County Board has approved plans for a residential high-rise in Rosslyn that planners say will be the tallest of its kind in Northern Virginia and set a new standard for environmentally friendly construction in the county.

The project will incorporate environmentally conscious materials and technologies into its design and construction, ideals that have been encouraged by county officials for the past several years to create buildings that consume less energy, use less water and even give off fewer toxic fumes.

Developers said their goal for the project is for it to be certified as a Leadership in Energy and Environmental Design (LEED) project by the U.S. Green Building Council. The rating system is a voluntary, consensus-based national standard for developing high-performance sustainable buildings that bases architectural decisions not only on cost and feasibility but also environmental impact.

The LEED rating system, for example, awards points to builders who redevelop sites instead of tearing up farmland. Points also go to buildings in locations close to established transportation arteries or mass transit, such as Metro. Depending on the scorecard, a building might meet the minimum level and be labeled "certified," or move through higher rankings of silver, gold and platinum. Certification occurs only after the building is completed.

In this case, high-performance details include a centralized heating and cooling system and an energy efficient floor-to-ceiling glass exterior facade, which increases light and provides expansive views of the Washington skyline. The building will also incorporate a rooftop heat recovery system that collects exhaust gases from the building's kitchens and dryer vents and recycle energy to cut the costs of heating and cooling.

Developers say it will also have a special system for managing wastewater for uses such as landscape irrigation and feature a six-level underground garage.

Why incorporate costly eco-friendly features when they are not required?

Developer Robert J. Curtis of Curtis & Facchina Development Co. said there are several good reasons.

"Bragging rights is one of them," Curtis said. "Marketing is the second -- to be more environmentally friendly [to attract buyers]. And the primary motivation is Arlington County's urging and incentives to get involved in this style of building design."

The building, which is set to rise 25 stories and include up to 337 units, is known as "Eighteen 81 Condominiums," a play on its location at 1881 N. Nash St.

While prices for the condominiums have yet to be set, Curtis said units will likely average between $500 and $800 per square foot. The units will range in size from 1,500 to 3,000 square feet.

The project was originally approved by the County Board in 2001. The site plan was amended June 26 to include some modifications: increasing the number of units from 176 to a maximum of 337, increasing the number of parking spaces, widening sidewalks, narrowing streets and committing to pursue LEED certification of the building.

County officials have said the project will assist in achieving their goal of expanding Rosslyn's residential base while featuring smart-growth components such as high-residential density, proximity to Metro, a reduced parking ratio and pedestrian-friendly, street-level retail.

The project was an initiative of board member Paul Ferguson (D) when he served as chairman in 1999.

Ferguson lauded the project for taking advantage of many eco-friendly techniques -- from possibly using recycled materials such as fiber in the carpets to buying locally acquired materials obtained within a 500-mile radius of the property to cut down on long-distance trucking.

Energy efficiencies are not only good for the environment but are also appealing to buyers, he said, encouraging local homeowners to contact Arlington County for information about adopting similar eco-friendly techniques.

"The developer isn't getting discounts" for doing this, Ferguson said. "They're doing it because they thought it was the right thing to do."

The measures are voluntary, he said, adding "the more they do, the happier the board members are that vote on the project. . . . We want them to make the investment in the building that benefits them and us."

Developers said groundbreaking could begin by early 2005. The building could be ready for occupancy by fall 2007.