Sustainable Building: Indoor Environmental Quality

Last month's article on sustainable building best practices focused on energy and resource efficiency, and how keeping those things in mind during the design and construction processes can make for a healthier and more profitable commercial property. This installment will deal with maximizing the indoor environment of a commercial property—making it healthier and more comfortable for those working inside it.

"The quality of the indoor environment is directly related to the health and productivity of the workers inside," says Brendan Owens, director of LEED (Leadership in Energy and Environmental Design) design and construction for the U.S. Green Building Council. "Many studies have proven that healthy, comfortable workplace environments result in decreased absenteeism and increased productivity. And indirect savings can be realized by attracting and retaining good employees, as the cost of hiring and training replacements really can cut into a business' profits."

Just as with the tips in last month's article, many of these strategies can be employed for new construction or renovation. These tips are again a simplification of the USGBC's LEED requirements.

Cost vs. Benefit
Any strategies for improving environmental quality (IEQ) must be addressed by all pertinent design and construction personnel during the design phase. Many improvements can be added at little or no extra cost when planned ahead, but trying to "tack them on" as you go often can result in cost overruns, construction delays and reduced effectiveness of whatever strategy you are trying to employ.

"Cost effectiveness with IEQ is hard to determine, because it depends on how much you value your employees, their productivity, and their well-being," says Nadav Malin, vice president of BuildingGreen Inc. and editor of Environmental Building News. "I think that most things one can do to improve the indoor environment are worthwhile if it makes people happier, more productive and feeling better about their work. But every employer will have his or her own way of evaluating that equation."

Common Problem Areas
Some of the most common factors that contribute to poor IEQ often are associated with water and/or moisture. Rain penetration, condensation, plumbing leaks and poorly drained and/or dirty cooling coils will lead to mold and mildew problems. Second-hand smoke, dirty carpets and harsh chemical cleansers also can contribute to poor air quality.

But not all IEQ problems have to do with air quality. Noise from office/manufacturing equipment, office mates or the outdoors can contribute to a less than optimal workplace environment. Poor lighting, either from low quality/too few electrical lights or the absence of natural light, can cause a host of problems from eye strain and headaches to costly worker mistakes or injuries.

The Building Envelope
Controlling the indoor environment starts with controlling what exterior elements are allowed to enter. A building's envelope must be as air- and watertight as possible, both to prevent leaks and the growth of mold as well as to ventilate with fresh air while removing any pollutants that might be present. The roof must be 100 percent leak-proof, but it must also drain water away from the building either by gutters or even a rainwater collection system. Any leaks or potential pooling spots must be fixed, and any spots that have had any mold must be cleaned, encapsulated or replaced.

The building envelope also must be as airtight as possible, preventing drafts and unwanted irritants from entering the building and keeping the treated air inside. Proper caulking, weatherstripping, insulation and window installation are the keys here. If you're especially keen on maximizing IEQ, you should choose caulks, adhesives and insulations that are free of volatile organic compounds (VOCs), which can off-gas irritating or harmful chemicals such as formaldehyde.

The HVAC System
"Air handling systems that are dirty, broken or simply not maintained are common contributors to poor IEQ," Malin says. If your system's ducts and cooling coils are dirty, then it stops being an air handling system and becomes a pollutant distribution system, sending mold spores, dust and allergens throughout the entire building. Malin suggests regular and thorough duct cleaning and super-high efficiency filters to trap irritants. "Commission the HVAC system once per year, no matter how old or how new the system is," Malin says.

Lighting
"Design for daylighting is a major factor in improving IEQ," Owens says. The human eye works better with natural light, UV rays can kill some microscopic organic irritants, and the presence of copious amounts of sunlight will reduce a building's electrical load. Daylighting strategies were discussed in last month's article, but it is important to note here that interior glare is a concern. Care must be taken to provide occupants with the ability to control the amount and intensity of natural light entering their space.

Even with optimal daylighting, artificial lights are a must. "Direct overhead 2-foot x 4-foot ceiling fixtures with magnetically ballasted fluorescent lamps as the only light source is very common, but that qualifies as poor lighting," Malin says. He suggests ambient lighting and task lighting for each workspace, with the ability to dim/brighten each light source provided.

Fit and Finish
Just as with the building envelope, the types of materials chosen to finish the interior can have an effect on IEQ. Low-VOC carpeting, paints, caulks and adhesives can reduce the amount of airborne irritants. Hard flooring surfaces are sometimes best as they do not trap dirt and dust.

Other strategies for improving IEQ include placing houseplants throughout a workspace, banning cigarette smoking from the inside of the building and near air intakes, and using green-seal certified cleaning agents. "Many IEQ problems are relayed as much to occupant behavior as to the building itself," Malin says.