Fluorescent Lighting
Payback time: Three years or less
If you are looking for a quick and easy green tactic, simply glance upward at your building’s lighting system.
“In the energy efficiency world, lighting is considered what they call low-hanging fruit,” says Ross-Bain. “Lighting paybacks are really short.”
Wherever possible in common areas and units alike, choose compact fluorescent lights, which use one-fourth of the energy consumption of incandescent lights. While the upgraded lighting option typically costs around $10 more per fixture, the extra upfront cost is quickly recouped in yearly energy savings. Plus, lower lighting watts also lead to lower cooling costs, adds Ross-Bain. Fluorescent lighting produces between 50 lumens and 100 lumens per watt, while incandescent lights emit more heat than light–only about 15 lumens per watt.
Ross-Bain also recommends adding occupancy lighting sensors to stairwells, which provides dimmer lights when there is no traffic. “Stairways do not get used that much, but the lights are on 24-7,” he says. “In a large multifamily project, the savings can be in the tens of thousands [of dollars] per year.”
Green Roofs
Payback time: Four to 13 years
Going green can be beautiful. Just look at the rooftop garden atop Gold Dust Apartments, a 70-unit low-income housing community in Missoula, Mont. The 2,550-square-foot garden incorporates permanent landscaping with vegetable gardening boxes. But this garden does more for the property than just present a pretty face: The green roof helps ensure that the building doesn’t generate stormwater runoff–a leading source of water pollution.
Green roofs, which are used for both stormwater management and energy savings, basically consist of vegetation and soil planted over a waterproofing membrane on a rooftop, with additional layers such as a root barrier or irrigation and drainage systems. “Green roofs are actually very simple,” says Gregg Lewis, a principal at SmithLewis Architecture, a Roanoke, Va.-based firm. “It’s basically a standard membrane roof with a couple extra layers.”
Green roofs typically cost anywhere from 30 percent to 40 percent more than a traditional roof (with a quality membrane), estimates Mike Perry, president of Building Logics, a Virginia Beach, Va.-based green roof provider. And the payback time can vary greatly, depending on the roof’s size, location, and configuration. The quickest payback Perry has seen: A New York City condo developer recouped the extra costs in less than four years by charging a premium for units that overlook the green roof, he says.
These vegetated roofs are sprouting up across the country, especially in big cities such as Chicago, Portland, Ore., Seattle, and New York. And in an effort to conserve water, many cities are beginning to require green roofs or offer incentives to encourage developers to go green on top.
In addition to mitigating stormwater runoff, green roofs provide a number of other benefits including: a reduction in noise levels from nearby traffic and airplanes; a prolonged life of the underlying roof membrane by protecting it from direct ultraviolet rays, and extra insulation for the building, which in turn reduces air conditioning costs by as much as 25 percent.
Plus, any rain that exceeds the capacity of a green roof can be tied into rainwater harvesting systems, which is especially important given the scarcity of water in many parts of the country. “Using reclaimed rainwater to irrigate landscapes, flush toilets, wash cars, and even to use for drinking water is going to be essential before long,” says Lewis.