Green Building

1. Where can I find green building contractors?
The U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) program lists LEED-accredited professionals in its LEED Professional Directory.
2. What is the LEED Green Building program?
The Leadership in Energy and Environmental Design (LEED) Green Building Rating System is an internationally recognized green building certification system. Developed by the U.S. Green Building Council (USGBC), LEED provides third-party verification that a building or community was designed, built, operated and maintained using strategies aimed at improving performance across all the metrics that matter most: energy savings, water efficiency, CO2 emissions reduction, improved indoor environmental quality, and stewardship of resources and sensitivity to their impacts.
3. Does the LEED program give points to food businesses for using environmentally preferable sourcing for their food service and catering functions?
Yes. Building owners and managers can now gain credit towards LEED certification by using sustainably harvested foods certified by pre-approved organizations including USDA Certified Organic, Food Alliance Certified, Protected Harvest Certified, The Rainforest Alliance, Fair Trade, and the Marine Stewardship Council's Blue Eco Label, and/or by acquiring food from within a 100-mile radius for food service and catering functions at the building. To achieve this credit, 25 percent of all food and beverages must meet one or more of these sustainability criteria. Double points are awarded if the food is both certified and locally harvested.
4. Should my community encourage home owners and businesses to install green roofs?
Vegetated roofs, or green roofs have a layer of living plants on top of the structure and the waterproofing elements. Green roofs provide shade and remove heat from the air through evapotranspiration, reducing temperatures of the roof surface and the surrounding air. On hot summer days, the surface temperature of a green roof can be cooler than the air temperature, whereas the surface of a conventional rooftop can be a stifling 90°F (50°C) warmer, creating what’s known as the heat island effect. Heat islands can affect communities by increasing summertime peak energy demand, air conditioning costs, air pollution and greenhouse gas emissions, heat-related illness and mortality, and water quality.

Many communities are taking action to reduce urban heat islands, including installing green roofs. Green roofs can be installed on a wide range of buildings, from industrial facilities to private residences. They can be as simple as a 2-inch covering of hardy groundcover (known as extensive green roofs) or as complex as a fully accessible park complete with trees (referred to as intensive). Green roofs are becoming popular in the United States, with roughly 8.5 million square feet installed or in progress as of June 2008.

Starting from the top, an extensive green roof has a layer of plants, which are typically sedums. These are low-growing, shallow rooting, drought tolerant plants. There are many different varieties of sedum, with different coloration and different flowerings, so that a roof can have a varied appearance, rather than looking like an entire crop of a single variety. The plants are in a growth medium, an engineered mixture of lightweight soils, vermiculite, and other materials that provides a good environment for the sedum. The shallow depth of the soil aids in keeping weeds from establishing themselves on the roof, since most weeds cannot survive in the arid and shallow soil conditions on a vegetated roof. Local plants that can survive in that environment may establish themselves on the roof, as well. Underneath the soil are several membrane layers, rather than just a single membrane roof. There is also a drainage layer (to allow excess water to move freely, rather than lifting the soil and having it flow off the roof in a mudslide, and a root barrier layer, which keeps the roots from penetrating the roof. The roof membrane sits on the roof deck, insulation, or structure of the building much like a conventional roof.

Installing the simpler extensive green roof may cost around $10 per square foot, while annual maintenance costs will run around $0.75 per square foot. Intensive systems are more expensive. Toyota recently introduced green roofing tiles, modular, interlockable grass tiles that are a lot lighter than other systems and easier to install. They're more expensive than other green roof products, but prices will likely drop as demand increases.

While the initial costs of green roofs are higher than those of conventional materials, building owners can help offset the difference through reduced energy and stormwater management costs, and potentially by the longer lifespan of green roofs compared with conventional roofing materials.

The EPA has excellent resources for those interested in learning more about heat island effect and green roofs.
5. How can my community take action to reduce urban heat islands?
Many communities are taking action to reduce urban heat islands, using a number of strategies, cool roofs among them. Cool roofs can lower cooling energy use, peak electricity demand, air pollution and greenhouse gas emissions, heat-related incidents, and solid waste generation due to less frequent re-roofing.

Building owners and roofing contractors have used cool roofing products for more than 20 years on commercial, industrial, and residential buildings. They may be installed on low-slope roofs (such as the flat or gently sloping roofs typically found on commercial, industrial, and office buildings) or the steep-sloped roofs used in many residences and retail buildings.

Through the ENERGY STAR program, EPA and the Department of Energy (DOE) help consumers and other purchasers identify the most energy-efficient roofing products. Roofing materials with the ENERGY STAR label have met the minimum solar reflectance and reliability criteria. A high solar reflectance is the most important characteristic of a cool roof as it helps to reflect sunlight and heat away from a building, reducing roof temperatures. A high thermal emittance also plays a role, particularly in climates that are warm and sunny. Together, these properties help roofs to absorb less heat and stay up to 50–60°F (28–33°C) cooler than conventional materials during peak summer weather.

The cost premium for cool roofs versus conventional roofing materials ranges from zero to 5 or 10 cents per square foot for most products, or from 10–20 cents for a built-up roof with a cool coating used in place of smooth asphalt or aluminum coating. However, a California study found that cool roofs provide an average yearly net savings of almost 50 cents per square foot. This number includes the price premium for cool roofing products and increased heating costs in the winter as well as summertime energy savings, savings from downsizing cooling equipment, and reduced labor and material costs over time due to the longer life of cool roofs compared with conventional roofs.

EPA maintains an Urban Heat Island Community Actions Database, which provides information on more than 75 local and statewide initiatives to reduce heat islands and achieve related benefits. Click here to find out which communities have cool roof initiatives underway.
6. Can my community reduce peak energy demand and reduce stormwater runoff by converting to cool pavements?
The term "heat island" describes built up areas that are hotter than nearby rural areas. Heat islands can affect communities by increasing summertime peak energy demand, air conditioning costs, air pollution and greenhouse gas emissions, heat-related illness and mortality, and water quality.

Cool pavements include a range of established and emerging technologies that communities are exploring as part of their heat island reduction efforts. The term currently refers to paving materials that reflect more solar energy, enhance water evaporation, or have been otherwise modified to remain cooler than conventional pavements.

Conventional paving materials can reach peak summertime temperatures of 120–150°F (48–67°C), transferring excess heat to the air above them and heating stormwater as it runs off the pavement into local waterways. Due to the large area covered by pavements in urban areas (nearly 30–45% of land cover based on an analysis of four geographically diverse cities), they are an important element to consider in heat island mitigation.

Cool pavements can be created with existing paving technologies (such as asphalt and concrete) as well as newer approaches such as the use of coatings or grass paving. Cool pavement technologies are not as advanced as other heat island mitigation strategies, and there is no official standard or labeling program to designate cool paving materials. To help address the growing demand for guidance on pavement choices, the Transportation Research Board has formed a subcommittee on Paving Materials and the Urban Climate.

EPA maintains an Urban Heat Island Community Actions Database, which provides information on more than 75 local and statewide initiatives to reduce heat islands and achieve related benefits. Click here to find out which communities have cool pavement initiatives underway.

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