TOPIC Indoor Environmental Quality (IEQ)
There is a lot of talk about sustainability these days. So much so, that the choice to go green is becoming less and less voluntary. In California, for example, all new homes are required to be net zero energy by 2020. This means that the amount of energy demanded by the building must not exceed the amount produced on site.
Boston has also established green legislation. It is the first city in the country to require all construction projects, over 50,000 square feet, to conform to LEED Certified standards.
To understand what all this means, it is important to step back and define sustainability. Sustainable developments are those that meet present needs without compromising the ability of future generations to meet their needs. Although this sounds relatively simple, the progression of multiple, third-party rating systems, like LEED, NSF-140 and Green Globes, have made sustainable building an intimidating endeavor.
LEED, which stands for Leadership in Energy and Environmental Design, is the most well-known green building rating system. It was developed by the U.S. Green Building Council (USGBC) and is a project-based system for designing, constructing, operating and certifying the world’s greenest buildings.
Under LEED there are rating systems for commercial and residential buildings. Our focus today is on LEED for Homes, which promotes the design and construction of high performance green housing. According to USGBC, a green home uses less energy, water and natural resources; creates less waste; and is healthier and more comfortable for occupants. Benefits of a LEED home include lower energy and water bills; reduced greenhouse gas emissions; and less exposure to mold, mildew and other indoor toxins.
The LEED for Homes Rating System measures the overall performance of a home in eight categories. Points are awarded for each category and contribute to a total level of performance indicated by four progressive LEED levels—Certified, Silver, Gold and Platinum.
Even though LEED rating pertains to the house as a whole, specific elements—like wool carpet---can help a home earn points toward certification. These points contribute under the LEED category of Materials and Resources.
Within this category, it states that if 45% of the carpet in a home is CRI Green Label Plus and is installed with Green Label cushion, it contributes 1 point. So, regardless of whether a carpet is wool or synthetic, it must be Green Label Plus to contribute to LEED. (See below clarification.)
Since wool is a rapidly renewable material, it can contribute an additional point if 2.5% of the total value of all building materials and products used in the project (based on cost) are rapidly renewable materials.
The higher the wool content, the more it contributes to the 2.5% minimum. This makes Wools of New Zealand Brand carpets particularly favorable since they must contain at least 80% wool.
I hope this clarifies some of the basic questions about LEED. As you can see, there isn’t a simple, straightforward answer when it comes to green standards. Much more information is available on USGBC.org/leed.
Clarification: According to Table 24: “Environmentally Preferable Products” in the Materials and Resources section of the USGBC’s LEED for Home Rating System, it states that carpet must comply with the CRI Green Label Plus program testing protocol. It is important to note that comparable VOC testing from independent, accredited labs may be submitted for consideration.