How to save energy in small offices

Help owners squeeze the last bit of efficiency into the design of these bread-and-butter projects
November 1, 2006
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Glazing figures prominently in a series of small office buildings showcased in the Advanced Energy Design Guide for Small Office Buildings. The guide was published in 2005 by the American Society of Heating, Refrigerating and Air-Conditioning Engineers of Atlanta; the American Institute of Architects and the U.S. Department of Energy, both in Washington, D.C.; the Illuminating Engineering Society of North America in New York City; and the New Buildings Institute of White Salmon, Wash.

According to ASHRAE officials, designers can earn credit for Leadership in Energy and Environmental Design certification by using this guide. The U.S. Green Building Council of Washington, D.C., administers the LEED program. “The design guide series is intended to provide prescriptive guidance to bring us 30 percent closer a net zero-energy buildings, meaning those that use equal or less energy than they produce on an annual basis,” says Lee Burgett, ASHRAE president, in a news release.

Specifically, the design guide has been added in LEED-NC 2.1 and LEED-NC 2.2 as a prescriptive compliance path to achieve LEED-NC Energy and Atmosphere Credit 1 for optimizing energy performance.

The guide establishes a previously unavailable prescriptive compliance path and enables small office design teams to earn LEED-NCz points without incurring the costs associated with whole building energy simulation.

The guide features profiles of eight buildings, one in each of eight U.S. climate zones, and describes how these buildings achieve energy efficiency. The following case studies number among those in the book, reprinted here with permission from ASHRAE.

The guide was developed by a committee of representatives from the above organizations. To order the book, call 800/527-4723 or 404/636-8400 or visit www.ashrae.org. The guide costs $57.

SpawGlass Construction Corporate Headquarters, Houston
Zone 2
SpawGlass Construction corporate headquarters, Houston
Located in Zone 2 with its extreme summer temperatures, SpawGlass Construction corporate headquarters houses the operations of a Houston contractor. The building also is the first LEED-certified building in Houston.

This single-story, concrete tilt wall, 20,000-square-foot building is on a generous 4-acre site. Designed by Kirksey Architecture of Houston, the building features a lobby and conferencing area, enclosed private offices and open-plan support space.

Some of the major features of the building include generous use of natural light, on-site storm-water retention and filtration, water efficiency and native landscaping. Windows throughout the building provide daylight and views for more than 75 percent of occupied spaces. An Energy Star-compliant roof system and paving surfaces with a high reflectance help minimize heat absorbed on the site. Water-saving fixtures include motion-sensor lavatory faucets, waterless urinals, and low-flow kitchen faucets and shower heads. In addition, vegetated swales and bioretention basins were designed to reduce the rate of stormwater runoff and to remove water contaminants.

Some of the energy-saving strategies include the use of occupancy sensor lighting, harmonic transformers, low-emissivity insulating glazing, an east-west orientation, appropriate glazing locations, and an efficient heating, ventilation and air-conditioning system.

Zone 5
Gilman Ordway Building at the Woods Hole Research Center, Falmouth, Mass.

During cold winters in Zone 5, rain, snow and ice dams can threaten a building’s envelope. Thus, controlling moisture and air flow in a building envelope in this zone is critical to a durable, comfortable office. In response, the Gilman Ordway Building, part of the Woods Hole Research Center, uses an environmentally intelligent design to create a healthy, comfortable workplace.

Although the Gilman Ordway Building uses a variety of passive and active environmental strategies, their integration was fundamental to the building’s success. Because of the center’s interest in reversing the progress of global warming, the design team at William McDonough + Partners in Charlottesville, Va., decided the building would operate without burning such fossil fuels as gas, oil or coal on site, instead using renewable sources of energy while aspiring to produce more energy than it consumed on an annual basis. Thus, the all-electric building relies on renewable energy sources, including an on-site photovoltaic array that powers the building’s closed-loop ground-source heat-pump system. Careful detailing of the envelope optimizes use of these resources—the building is well-insulated, with an extremely secure envelope.

Through careful siting, the building’s design and location take advantage of natural features to achieve thermal comfort. The 19,200-square-foot office building is elongated along an east-west axis to gain optimal solar energy. Skylights and full-height windows provide abundant daylight and access to views, while ventilation systems and operable windows supply fresh air. A temperature and humidity monitoring system further enhances indoor environmental quality.

The predominance of natural wood finishes inside and out, and the preservation of the original building’s traditional appearance, give the center a warmth and character familiar to its New England setting. Visitors within its comfortable, gracious spaces do not immediately recognize the office as an advanced, high-performance building. The integration of new technology and New England sensibility is one of the building’s greatest successes.