Sustainable Building (Part 1): Energy Efficiency

Green building has been gaining momentum over the last few years as building professionals and building owners increasingly recognize the benefits to their own bottom lines. According to the U.S. Green Building Council (USGBC), there were about 1.1 million square feet of commercial building space certified under their LEED (Leadership in Energy and Environmental Design) program in 1999. By 2004, that figure rocketed to more than 194 million square feet.

"People are becoming more aware of not only the environmental benefits of green building, but their own economic benefits and the benefits of all who work or live inside the building," says Brendan Owens, director of LEED design and construction for the USGBC. "Commercial property owners especially love the fact that healthy and comfortable indoor environments result in decreased absenteeism and increased productivity, which can lead to increased profits."

We will discuss two main areas on which contractors and owners should focus: energy and resource efficiency (part 1) and indoor environmental quality (part 2). Many of these strategies can be applied to both new construction and renovations.

Cost vs. Benefit
In the past, contractors and building owners might have been intimidated by the higher costs associated with sustainable building (either real or perceived). But as the technologies have progressed and techniques have been further perfected, many sustainable practices can be implemented at little to no additional cost, and most result in lower costs or savings down the line. Maximizing benefits starts during the design process.

"Simply tacking on a bunch of green features onto one's conventional design will often add cost and complexity, and may not deliver a lot of benefit," says Nadav Malin, vice president of BuildingGreen Inc. and editor of Environmental Building News. "The key is finding designers who have done it before and empowering them to use an integrated design process involving the whole project team from the earliest stages of the design process to develop the best solutions."

This approach sometimes can result in marginally higher first costs, usually due to the lengthened design process, and sometimes more expensive equipment. But often there are little to no increased first costs, and the resulting operating costs typically are much lower, saving even more money. Also, some green features that add cost (upgraded windows and insulation, for example) often will be made up for by allowing for less expensive materials or equipment down the line (downsized mechanical systems, for instance).

Energy and Resource Efficiency
The USGBC's LEED guidelines spell out many sustainable categories and techniques, from innovation in the design process to sustainable site selection to water efficiency, among others. These guidelines spell out how to achieve LEED certification. But even if you aren't interested in pursuing a certification for your building, they provide numerous hints and tips to make a building easier on the environment and less expensive to own and operate.

The Building Envelope
"Anything you can do to optimize energy efficiency during the design phase is a built-in long-term operational cost reduction," Owens says. This includes, among other things, sealing all drafts and air leakage in the envelope, investing in upgraded windows and ensuring they are installed properly and tightly, and installing high-performance insulation products.

If your concerns run beyond simple cost reduction and energy efficiency and into lessening environmental impact, you can choose recycled or rapidly renewable materials (no old-growth lumber, Forest Stewardship Council certified lumber, poplar Oriented Strand Board, soy-based insulation products, etc.)

Glazings and Daylighting
By maximizing the amount of natural light allowed into a building, you can lessen the need for electric lighting (and the resulting wasted heat generated by the bulbs) and take advantage of solar heat gain, if desirable. There also have been numerous studies on daylighting and its positive effect on commercial sales, occupant health and productivity.

Proper daylighting strategies include proper placement and size of windows, low-E glazings where applicable, and sun controls (blinds, light shelves, overhangs, etc.) to maximize benefits and minimize energy loss.

"Daylighting is a very compelling feature, but doing it right requires sophistication and experience on the part of the designers," Malin says. "It may add cost, but it must be worth it as skylights are now standard at all new Wal-Mart stores."

Right-sizing HVAC
In the not-so-distant past when almost all building envelopes were drafty to a certain extent, it was common practice to oversize HVAC equipment to make up for air and energy leakage. But with a tight building envelope, you are able to specify much smaller and more efficient equipment. Sealing and insulating all ductwork is another easy-to-implement sustainable feature, and specifying equipment that uses no CFCs in its refrigerants will provide environmental benefits both inside the building and out.

Water Efficiency
By using high-efficiency fixtures such as low-flush toilets, waterless urinals and sensor-activated faucets, you will greatly reduce the amount of water your building uses and your resulting water/sewer bill. You also may consider rainwater collection and gray water reuse for non-potable water applications such as toilet flushing, mechanical systems, custodial uses and irrigation. Landscaping with indigenous plants or those that require little to no water (called xeriscaping) is another effective strategy.

Renewable Energy
Some of the more expensive and/or involved options for maximizing energy performance include the use of renewable energy strategies. These may include solar, wind, geothermal, biomass, hydro and bio-gas technologies. The expense can be offset first by considering them during the design process instead of trying to tack them on later into the project. Also, tax incentives and net metering (where the utility company actually buys back surplus energy that your building has created) are available in certain parts of the country.

In the next installment of this story, we will discuss sustainable building strategies that can maximize the indoor environment of your building.