| NEWS | DESIGN | BUILDING | DESIGN TOOLS | ENVIRONMENT | CULTURE |
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Gentle on the Beach | |
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Chesapeake Bay Foundations | |
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Chesapeake Bay Foundations Low-Impact Architecture The building is conserving in both its form and composition. An open office plan promotes natural ventilation and daylight distribution, which minimizes dependence on electric lighting. A glazed wall on the south heats the interior in the winter, while trellised sun shades keep it cool in the summer. A detached 200-seat conference facility further minimizes energy consumption by drawing on energy reserves only for those hours when conferences are in session. To the greatest extent possible, construction materials were recycled, recyclable, or both. Certified wood came from diverse, canopied forests that have been managed according to strict sustainable standards of the U.S. Forest Stewardship Council. Framing timbers were made from custom-engineered laminated beams manufactured from second-growth wood. Structural insulated panels were used as an alternative to conventional framing; these require considerably less wood and have a higher insulation value. Recycled materials also included galvanized steel siding, galvanized roofing, and medium density fiberboard. The sun louvers were made of salvaged barrel staves from a nearby pickle factory. The flooring is cork, which insulates and dampens sound while providing a cushioned walking surface. It is also a renewable resource because it can be stripped from a living tree without harm, allowing the tree to grow another layer. Other renewable materials include cork tackboards, natural linoleum, and bamboo flooring. Using these materials eliminated the need for manufacture of virgin materials from petroleum and other nonrenewable resources. In addition, the center's decking was pressure-treated without the use of arsenic or other toxics. All paints, sealants, and adhesives were chosen for low contents of volatile organic compounds (VOCs), which contribute to indoor air pollution. Concrete from demolition of the site's previous buildings was reused in roadbeds. Most materials were produced within 300 miles of the facility to reduce air pollution associated with their transport. Mechanical Systems Only in extremes of heat and humidity does the building require conventional air conditioning. When sensors determine that the outdoor climate is amenable, the mechanical system shuts down, motor-operated windows open, and signs tell employees they can open their windows to take advantage of the bay's cooling breezes. Photovoltaic panels produce a portion of the building's electricity, and solar hot-water heating reduces electricity demand. Approximately 30 percent of the building's energy load is provided through building-integrated or directly connected renewable energy sources. A closed-loop geothermal heat pump system relies on the constant temperature of the earth below the frost line. Forty-eight wells, each 300 feet (91 meters) deep, use the earth's constant temperature as a heat sink in the summer and a heat source in the winter. Desiccant systems decrease humidity and greatly reduce energy demands on mechanical equipment. Water systems One of the building's most prominent architectural features is its collection of massive cisterns that capture rainwater for everything but drinking, reducing by 90 percent the need to draw from wells and public water sources. Composting toilets are nonflushing units that recycle waste and greatly reduce the amount of water needed by an office building. The CBF staff has used composting toilets at various sites for 20 years, and they note that the quality of the compost is comparable to fine topsoil. Site Restoration The building was sited on the footprint of existing buildings so as not to increase existing impervious surface or site disturbance. Construction was not permitted to disturb untouched portions of the site. Harmful runoff from surfaces is minimized by placing some parking under the building and using permeable gravel surfacing for parking outside the building. Any stormwater runoff flows to a constructed wetland via a bioretention system designed to treat oils. This protects the water quality in the adjacent creek and bay. Drought-tolerant, native plant species have been reintroduced to return the site's ecosystem to its original state and to minimize the need for irrigation. Meadow and grassland plantings require only annual mowing, reducing the amount of fuel necessary to maintain the site. The overall design concept extends beyond the local site and building. The CBF also promotes sound transportation policies. The center is located near existing retail and residential areas. Some employees walk, bike, or kayak to work. Bicycle storage, lockers, showers, and changing rooms are included in the facility. Video-conferencing technology reduces the need for staff to travel to meetings. Results Compared to typical offices buildings of the same size, the Merrill Center uses 50 percent less energy, thereby reducing air pollution. It uses 1/10th the water, and leaves 85 percent of its site undisturbed. The construction cost was $199 per square foot ($2150 per square meter); one quarter of that was for "green" features, and much of that will be recouped through lower operating costs. Despite some improvements over the past 35 years, the Chesapeake Bay's ecosystem is still seriously endangered. It has lost 90 percent of its underwater grasses and 60 percent of its wetlands. From their new site, CBF staff and volunteers will continue work to restore shoreline habitats and wetlands, replanting them with native grasses. Perhaps this newest human intervention will further inspire work to rebuild the fragile water and land habitats. Project Credits Owner: Chesapeake Bay Foundation
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