The Green Machine

Over the past decade, sustainable, or “green” building design has become quite fashionable, as commercial and institutional clients have grown wise to its broad appeal among their members, or shareholders, and the public. The buzz about sustainable design leaves serious environmentalists both hopeful and worried, because for every earnest client asking for environmentally sensitive design, there is a likely poseur simply trying to impress people with dumb ideas. “Greenwashing,” says Donna McIntire, program manager for the U.S. Green Building Council, an advocacy group in Washington, D.C., “is rampant in the industry.”

Few organizations care more sincerely about sustainability than the Chesapeake Bay Foundation: For 35 years, the CBF has led a massive effort to clean up its namesake, the nation’s largest estuary. Over the past two years, as the foundation’s directors prepared to design and build a new 32,000-square-foot headquarters near Annapolis, Maryland, they had to walk their own talk: They needed to create a building their ardent constituency would approve of, and uphold their foundation’s ideals by protecting the Chesapeake Bay, which lies 100 yards from the building, across a small beach with a couple of lonesome old trees and sublime views to the south.

Now that the building is finished, two years later, those directors should be able to sleep at night. Their new compound, designed by the Washington office of SmithGroup and a host of sustainable-design experts, has to be, as they claim, one of the “greenest” buildings of its kind. The final product–a fairly simple shed of galvanized steel, frankly articulated wood members, and three huge cisterns for rainwater–proves once again that architects needn’t sacrifice beauty for sustainability.

The CBF came to the site at the invitation of the neighbors. Before the CBF chose the 30-acre property for its headquarters, formerly the historic Bay Ridge Inn, the site was the target of a plan to build dozens of new houses, which made the relatively few people who live nearby nervous. But when the community learned that the CBF was looking for land for a new headquarters, they invited the foundation to consider the site. The parcel was perfect for the mission of the CBF, which wanted to consolidate 100 of its 200 employees from four locations around the Annapolis area. The previous landowner sold the CBF the land at a price below market value, and, as a nonprofit, the organization secured a low-interest loan and sold the site’s excess development rights to the state of Maryland.

“We didn’t think in our wildest dreams that we would get a deal like this,” says Charles D. Foster, Foundation director.

The foundation had developed a few sustainable buildings in the past–but had completed nothing on such a large scale. The CBF turned for help to Janet Harrison, an Annapolis architect who specializes in sustainable design. Harrison began looking for a suitable rating system by which to measure the project’s sustainability. She settled on the U.S. Green Building Council’s Leadership in Energy-Efficient and Environmental Design, or LEED. The LEED system is the “strictest and most rigorous” of the various green benchmarking programs available, Harrison says (see “Degrees of Green”, page 49). “But the CBF really wanted to go up against it and see what they could do.” The CBF studied the LEED criteria, which cover everything from site preparation to indoor air quality, and developed a wish list of sustainable design features.

The budget for the building, of course, would limit the amenities the CBF could afford, so the programming phase began in October 1998 with a two-day peer-review critique led by specialists at what is now known as the Sustainable Building Industries Council (SBIC). “All these projects are individual, and you have to figure out what consultants would make sense,” says Ellen Larson, program and policy manager of the SBIC. “It’s a combination of a charette and a peer review.”

The group, which met at the old Bay Ridge Inn just before it was torn down, included representatives of SmithGroup, the Maryland Energy Administration, the state’s Department of Natural Resources, the World Wildlife Fund, and the National Renewable Energy Laboratory.

“A lot of philosophical questions came up,” recalls Harrison, who kept track of the building’s LEED adherence throughout design and construction. “Steel or wood? Do we save the trees? Or do we use the trees to encourage certification of sustainable forests?”

Several major components were removed from the design during the initial review session, such as a radiant heating system considered for the floors. “It had a lot of benefits, but was redundant with the heating system,” Harrison says. And though the building’s south elevation is mostly glazed, the original scheme included much more glazing, which the team replaced with structural insulated panels. “Every time we saved money” during the review, notes Harrison, “we rolled it back into the building.”

The cost per square foot of the building alone came out to be about $199, of which $30 to $45 went toward green elements. That figure sounds extravagant, but the foundation’s board fell in love with the LEED system and wanted its highest, or “platinum” rating (see sidebar, at right), and succeeded. As items came out during the peer review, and later, during value engineering ($30,000 was saved by leaving sheet nails exposed, for instance, rather than covering them over), “our board said, ‘Cut what you want, but don’t cut that rating,”‘ says Foster. “The LEED rating became a shield to protect the green-ness of the building.”

As a result of this adherence to the LEED, nearly every facet of the project suggests sustainability. The Merrill Center lies at the end of a two-lane road, newly painted with bicycle lanes, that stops near the water’s edge. It’s quiet out there. The drive curves through a wood to a gravel parking lot, which doubles as a “bioretention” system developed by civil engineer Greenman-Pedersen and site consultant Karene Motivans, an ecologist who works with the National Institutes of Health. The choice of gravel over asphalt paving cuts the amount of land impervious to storm water, which as a result percolates away from the parking area through a natural filter of locally native rushes, asters, irises, and wool grass to a newly built non-tidal wetland. Practically no runoff from the site ever reaches the bay.

The CBF wanted to disturb as little of the land as possible. Eighty-four percent of the site remains open, a ratio achieved by building atop the footprint of the Bay Ridge Inn’s former pool house. Initially, the CBF hoped to reuse the old building, but it was “too far gone” says Foster, so the building was picked apart and its wood recycled.

The new building boils down to two chamfered volumes: a large, rectangular office block and a smaller cube holding a conference annex. Both pieces sit atop 7- to 10-foot-high piers that open the ground beneath for 45 parking spaces (though many CBF employees bicycle or kayak to work). The form is vernacular: “We looked at a lot of fisherman’s shacks and watermen’s buildings, all raised up on piers with simple geometries and shed roofs,” says SmithGroup project architect Gregory A. Mella.

In the office block, structural bays measure 60 feet deep, the critical distance for allowing natural light to filter to the building’s northern edge. Its glassy south facade sits behind a 10-foot-wide porch running the length of the building and is delineated by a frame of engineered-wood members. The porch’s frame holds a series of brisesoleils (which baffle the summer sun) made from recycled pickle-barrel wood obtained from a disused factory nearby. has raised concerns about glare.) Photovoltaic arrays situated at either end of the porch generate only 2 percent of the building’s energy load, but CBF wanted to keep them in the design as teaching tools. At either end of the office portion, cabled X-braces stabilize the long building against high winds.

The building is framed and clad largely in structural insulated panels: Each panel consists of two thick pieces of oriented strand board sandwiching a 6- to 8-inch-thick layer of insulation. “You build the structure just like a barn,” says Mella, first assembling the walls from individual panels joined flat on the ground, then raising the walls upright. The panels remain bare on the interior except for battens covering the joints. A girdle of galvanized steel wraps the exterior “like a blanket,” Mella explains, because it has high R-values for insulation; its content is 75 percent recycled metal. The surface was left unpainted both to avoid volatile organic compounds in paint and to ensure that the steel will recycle readily at the end of the building’s life. A small volume on the building’s north side holds a locker room; it is clad in a ground-faced masonry block containing recycled aggregates and fly ash.

The open-plan interiors are a showcase for green materials. The floor of the lobby is made of 3/4-inch bamboo boards. Office floors are finished with cork beeswax, which absorbs fugitive noise in the large spaces. The bamboo, cork, and engineered wood are among the few exceptions to a design-team rule: building materials may originate no more than 300 miles from the site.

The office ceilings will stay exposed except for suspended trays of gypsum, (74 percent recycled) which hold the light fixtures.

Open offices were the only way to both ventilate and light the building naturally. Light sensors mounted throughout the offices judge when the daylight dims enough to turn up the electric lights. And temperature and humidity monitors outdoors suggest when the air is comfortable enough to activate the “Open Window” signs that hang in each office quadrant: Staff may then crank open the glass panels and let in fresh air. Roof dormers open mechanically to help draw air through the spaces. “This region isn’t the most suitable for natural ventilation,” Mella observes. “It’s a little humid. We estimate [the staff] will be able to use it about 10 percent of the year, based on our idea of thermal comfort. But knowing these people and how hands-on they are, they’ll probably use it a lot more than that.”

Although the building’s vital organs hide behind all the obvious amenities, they offer the most compelling signs of sustainability. Renewable energy sources supply about 34 percent of the building’s total load. The indoor air temperature is regulated by a “geo-exchange closed loop”: The heat pump connects to vertical wells that reach 300 feet into the ground to take advantage of the earth’s natural temperature of 55 degrees Fahrenheit, which helps to cool the building in summer and heat it in winter. The roof collects rainwater and directs it to one of the three 12,000-gallon cisterns for storage. From there, the water is filtered of particles, treated with chlorine, filtered again through carbon to remove the chlorine, and used for the sprinkler system as well as for hand washing, mop sinks, and laundry. (Local codes, however, prohibit using rainwater for drinking, cooking, or showering.) And in the restrooms (where occupancy sensors control the lights), the design team specified Clivus Multrum composting t oilets. All waste winds up in a large container beneath the building, where it is turned into fertilizer to be used on the site.

As the CBF staff moved into their offices in early December, Foster began verifying that all the building’s systems perform as designed. The CBF will use the “Bonneville” standards for building performance, set by the city of Bonneville, California, which are among the strictest in the nation. The U.S. Department of Energy, Foster says, has offered to monitor the building systems over the long term, which is fine with him. “We see part of the purpose of the building as providing a [teaching] tool,” Foster explains. “Green buildings as green buildings are not the CBF’s mission. Our mission is to save the bay.” And now the foundation’s staff can turn its full attention back to that majestic body of water, which slowly changes colors throughout the day.

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