GUEST COLUMN: Adding Green (Roofs) to Save Green in Multifamily Properties
- May 26, 2009
By John Francis, NV Roofing Faced with the current state of the economy, multifamily owners and property managers must continually seek ways to maintain a cost-effective building while adhering to environmental guidelines that will help to increase their property value and competitiveness in the market. Many of them would really like to reduce costs to weather the storm. But they can’t afford for their cost-cutting measures to jeopardize their environmental protection efforts, so they will need to identify options that will actually save them money in the long run. When multifamily properties are faced with this challenge, a green roof may be the solution. Property managers of apartment buildings and condominiums are finding that having a green roof can be a smart financial decision for the property’s entire community, just as driving a hybrid car and installing energy-saving light bulbs can make monetary and environmental sense for individuals.A green roof’s superior insulation reduces a building’s energy bills. And with energy costs constantly climbing, having a green roof can minimize the economic burden of these costs year after year. Most traditional roofs use polyisocyanurate (ISO) insulation, which can lose its R-value, or ability to insulate. The R-value of ISO insulation is difficult to measure for any length of time because of thermal drift, resulting in heat loss and increased energy consumption. But a properly designed green roof will employ an extruded polystyrene (XPS) insulation that is guaranteed by the manufacturer to hold 85 percent of its R-value for 30 years, allowing building owners and property managers to calculate their energy-savings for decades. But a green roof’s insulation benefit is not the only financially sound reason to consider installing one—having a green roof can also result in tax breaks. As of August 2008, at least eight states and 22 localities have endorsed green policies. While some of these locations simply require that new government buildings be constructed in line with the U.S. Green Building Council’s LEED (Leadership in Energy and Environmental Design) standards, others give tax breaks and expedited permits to green buildings. And a few policies, such as one in Maryland’s Baltimore County, present tax credits to builders for green construction. While installing a green roof alone may not make a building eligible for tax breaks, it will qualify the building for significant points through the LEED system.What’s a green roof?A “green roof,” also called a planted roof, is defined as a roofing system that is topped with vegetation. Although this definition is not all-inclusive (there is such a thing as a non-vegetative green roof), planted roofs have numerous environmental benefits in addition to the energy cost-savings due to the superior insulation. One of the most significant benefits of planted roofs is that they reduce storm water runoff by actually absorbing the water, thereby keeping it from running into and polluting nearby lakes, streams and other water resources. Because the runoff is a problem often caused by traditional roofs, many municipalities across the U.S. are considering, or have already instituted, a tax on excessive storm water runoff to offset the cost of expensive water treatment programs. A green roof with 2.5-inch deep soil retains approximately 67 percent of rainwater. During a major rainstorm, which generates about 1.25 gallons of water per square foot, the roof will generally absorb a half gallon of water per square foot (about 40 percent). Because planted roofs do so much to minimize the storm water runoff problem, they are often exempt from the tax or may qualify for a reduced tax. But the benefits don’t stop there. Vegetation on the roof helps to stabilize its temperature, decreasing overall energy consumption of the building and lowering cooling bills. For example, on a 90-degree day, a conventional black roof is about 170 degrees and a reflective white roof will range between 110 to 120 degrees. In comparison, a vegetative roof will actually be a little cooler than the temperature outside. Green roofs for less green Vegetative, or planted, roofs have clear environmental and long-term cost benefits, but the immediate cost of an extra $10 to $20 per square foot can sometimes cause multifamily property managers to seek cheaper alternatives. Having vegetation on the roof is not the only way it can be made green. There are other cost-effective green innovations. NV Roofing, based in Northern Virginia, just announced its completion of the first non-vegetative green roof in Washington, D.C—on Bon Wit Plaza (pictured), an apartment building that rents about 70 percent of its units to George Washington University students. The new non-vegetative green roof, also called the “clean green roof,” cuts down on Bon Wit’s energy bills, qualifies for LEED points and is considered green because of its recycled content and sustainability. The use of recycled materials in its design reduces energy costs and also mitigates storm water runoff. It even has a 25-year no-leak warranty.This type of roof uses a waterproofing membrane and environmentally friendly, field-proven insulation to achieve optimum performance and sustainability. It is equivalent in cost to a properly installed standard commercial roof, but—unlike a standard commercial roof—it is guaranteed to cut energy costs for decades, is EPA- and building code-compliant and may qualify for a host of tax benefits. This green roof system is also designed to last more than 40-plus years, well beyond conventional roofs, and can be recycled at the end of its life cycle. The coal tar-based self-adhered membrane is a significant reason as to why the non-vegetative green roof is so environmentally friendly, and still very affordable. This type of membrane has all the benefits of a coal tar pitch roof, without the negative environmental and health issues. It also outlasts standard roofing membranes by up to 30 years and is fully recyclable. Many roofs are installed using a technique called “hot mopping,” which, in heating up tar, emits toxic fumes known as volatile organic compounds (VOCs). The method does not comply with current EPA regulations. However, the self-adhered coal tar membrane forms a structural bond with the substrate and is watertight within minutes, without the negative environmental impact.There are still other options for the budget-conscious among “conventional roofs,” but with these, some of the green benefits such as storm water management and sustainability are lost. Roofing such as thermalplastic (TPO), ballasted EPDM and any white roof system approved by Energy Star can have some green properties. Even though a planted roof or non-vegetative roof may be beyond a building’s budget, there are other affordable alternatives that are partly green and can be eligible for some LEED points. It is important to discuss with a roofing contractor which options will be best suited to a specific building.Identifying the best green solution for your multifamily propertyGoing green has been all the rage as of late, and roofing is not excluded from the movement. The roofing industry is certainly providing a variety of solutions to better the environment, but while many of these are viable, there will always be a few that do not prove to be everything they promise. Therefore, it’s essential that property owners and managers understand the different offerings. The U.S. Green Building Council publishes LEED guidelines that can help determine which building elements are actually environmentally friendly. Because there are constant changes in guidelines within the construction industry, the USGBC is planning to introduce early next year a new generation of design standards that will include specifications for the latest developments in roofing design. In the meantime, consumers have to do much of their own research in order to determine the best green roof provider in their area. Your local USGBC chapter can provide a list of area con
tractors that specialize in green design. Extensive information on corporate, sales and property tax breaks, rebate programs, grants and loan programs, and other financial incentives for going green can be found at www.goodtobegreen.com and www.dsireusa.org. You’re likely to find that much green can be saved by implementing green and sustainable energy initiatives into your buildings.John Francis is owner and CEO of NV Roofing, which provides residential and commercial roofing solutions in the Washington, D.C. metro area. NV Roofing installs vegetative and non-vegetative green roofing systems, which utilize recycled materials.