The Big Picture

Nov. 1, 2002
Sustainability is a concept that is becoming more associated with educational facility design. It enables schools to produce a high-quality facility that

Sustainability is a concept that is becoming more associated with educational facility design. It enables schools to produce a high-quality facility that has a minimal impact on natural resources and costs less than a conventionally designed facility.

Traditionally, architects design a facility, and pass the drawings to consultants and engineers to design the systems. In sustainable design, a team of architects, engineers, general contractor, construction manager, and facility administrators work together from planning through construction to ensure a facility that is designed to maximize the effectiveness of design, engineering and constructability.

Holistic approach

In conventional academic facility design, efforts to reduce operational and maintenance costs often focus on energy efficiency. Sustainable design is much more than that. When a design team looks at the process holistically, it is looking at not only individual energy-efficient systems, but also the impact of building placement, orientation, and architectural and systems design on the facility's energy-use patterns.

For example, reducing high heating and cooling costs starts with optimal building orientation with respect to the sun. This takes advantage of natural windscreens in the form of hills and wooded areas to correctly size the heating and cooling equipment. Only then does the approach consider specific systems, such as windows. The solution to reduce energy use may call for setting the plane of a window back from the edge of the building under an overhang to reduce the solar gain, as well as specifying an energy-efficient window system.

In contrast, a narrow focus on energy-efficient systems might focus only on the window system, losing sight of the additional savings in resources and operational expenses that can be gained by effective siting, orientation and design of the facade. This also can yield savings on the capital costs of HVAC equipment required for the building: by limiting the solar gain on the building, the cooling load is reduced, and thus the size of the equipment required is also reduced.

A simple improvement to diminish the energy load is use of light-colored roofing materials that reflect sunlight and reduce heat gain. A more holistic approach takes into consideration building orientation, as well as the roofing system and materials, and yields even greater benefits.

A step further is use of green roofs — roofing systems that integrate low-growing local or regional native plants, which under normal conditions do not require additional water or a lot of maintenance. Green roofs not only provide effective building insulation from the soil layer, but also reduce rainwater runoff into the storm sewer system.

Providing a restored habitat through the use of green roofs is another benefit; they also reduce the “heat island” effect of the building and offer a natural area for users to relax, meet or study.

Air quality and comfort

Form and function also converge in sustainable design of the mechanical system. Traditionally, air is supplied and exhausted by way of ceiling vents, which requires greater air volume and larger equipment to force it down from the ceiling level of 10 feet to the three-foot work zone, where it is used. A sustainable-design approach might use a raised floor as the plenum for air supply. This means heated or cooled air needs to be moved only three feet from the source to the work zone, yielding capital savings on the size of equipment, as well as operational costs.

Exhaust vents can be placed in the ceiling, with the added advantage of a fresher, one-way flow of air and the potential for improved indoor air quality. This approach is favored in office buildings, and it also has the potential for application in selected academic settings, such as administrative offices, libraries, and in college and university classroom buildings.

An effective mechanical system can help maintain good indoor air quality. Selection of materials and furnishings with low levels of the volatile organic compounds (VOCs) found in many types of glue, paints and finishes is essential to minimize noxious off-gases. Studies have shown students and staff perform better in facilities with good indoor air quality and comfort.

Lighting the way

Lighting significantly increases maintenance and operations costs, yet most academic facilities are designed with a preponderance of 2-foot by 4-foot fluorescent trough light fixtures. These are an inefficient source of light, and they create shadows and glare, particularly on computer screens. Indirect lighting using pendant fixtures that reflects the light from compact fluorescent bulbs off the ceiling provides higher efficiency with fewer fixtures, which means reduced energy loads and fewer bulb replacements.

Daylighting is another opportunity to reduce costs. A light shelf — a horizontal plane set down 18 to 24 inches from the top edge of a window — blocks solar gain as it bounces daylight into the room, saving on the cost of lighting by reducing the number of light fixtures needed. Light shelves typically are used on the south side of a building. In the winter, the angle of the sun is lower and allows for the positive effects of passive solar gain.

These lighting approaches provide better visibility for working and studying, and reduce the building's energy load. This translates to a reduction in the size of the transformer as well as day-to-day operational costs.

In addition to lighting, other electric and electronic equipment can be a drain on resources and budgets. Sustainable design calls for specifying equipment and appliances that have the U.S. Department of Energy's Energy Star rating.

Conventionally designed sports facilities consume huge amounts of water — for athletic fields, in food service and concessions, and in restrooms and locker room facilities. At the same time, associated paved parking facilities create an enormous volume of stormwater runoff, sending pollution into streams and waterways.

Reducing water consumption starts with sustainable site design. Consider landscaping with local or regional native plants, which do not require much, if any, additional watering under normal conditions. Use drip irrigation systems; or collect and use rainwater or building grey water for watering grounds. Reduce and reuse stormwater runoff through effective grading, water-permeable paving, and water-retention basins or swales.

When these steps are combined with installation of low-flow plumbing fixtures throughout a facility, the facility has less water consumption and operational costs, and may allow a district to decrease the size and cost of its wastewater infrastructure.

Long-term benefits

Sustainable school facility design offers many benefits, not the least of which is a significant return on investment. Although some of the building systems, fixtures, furnishings and equipment used in sustainable design may have higher initial costs, many of these pay for themselves in as little as one to three years because of reduced operational and maintenance costs.

And the capital costs of typically big-ticket systems — particularly HVAC system and plumbing infrastructure — can be reduced as a result of an effective, holistic approach to architectural design, engineering and construction.

This approach applies to planning a classroom facility, residence hall, library or administration building. It is even more crucial in specialized facilities, such as sports facilities or laboratories, which historically consume two to five times the energy of a general classroom building.

In many cases, the total cost of an educational facility built with sustainable-design features will be the same if not less than one that has been conventionally designed and constructed. What it takes to accomplish this is a committed team of professionals — architects, structural, mechanical and electrical engineers, and school administrators and facility managers — with the perspective to see the big picture.

DeVolder is an associate with CDFM2 Architecture, Kansas City, Mo. He is accredited in Leadership in Energy and Environmental Design (LEED) through the U.S. Green Building Council.

Other sustainable-design methods

Sustainable design also involves the use of materials from the region, and recycled and renewable resources. The use of local and regional building materials reduces the energy needed to transport supplies, and benefits the local and regional economy.

Recycled materials — steel, wood, paper and plastics — reduce the impact on natural resources and can even reduce operational costs because of durability and ease of maintenance. The same applies to renewable materials such as bamboo, a fast-growing grass that can be harvested for use within five to 10 years. It is being used in place of hardwood in flooring and wall panels. On the other end of the recycling spectrum, building materials such as lumber and gypsum board can be recovered and recycled from renovations, and recycling stations can be built into the design of educational facilities.

Power generated from renewable or “green” energy sources — such as wind turbines and photo-voltaic (solar) arrays — is available from some energy producers. They also are becoming an economically competitive alternative to coal- and gas-fired power plants. Especially in the Midwest, wind power soon will have the potential to be cheaper than coal- or gas-fired power generation, without the risks of nuclear power.

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