A major tenet within the green building rating systems is that of supporting “local” products and businesses. Regionally manufactured and extracted materials reduce environmental impacts by reducing emissions of greenhouse gasses during transportation, while supporting local economies. Fortunately for environmentally conscious consumers, there are stone quarry sites within 500 miles of nearly any building site in the United States and Canada.
LEED Credits MR 5.1 and 5.2
Local Materials in New Construction
Requires that the product be extracted, processed AND manufactured within a 500 mile radius of the site. Either 10% (or more) or 20% (or more) of total materials in the whole project have to fit this criteria, based on cost of materials. If only a certain percentage of a product fits these qualifications, then that percentage of the total price of that product is used in the calculations of total materials cost in the project.
Local Materials in Homes
LEED Credits MR 2.2
Requires that the product be extracted, processed AND manufactured within a 500 mile radius of the site. LEED-H bases this per building component and not as a percentage of total materials in the project. In this way, components would not need to rely on other products in the project to qualify for local credits. At least 90% of the component per weight or volume must meet the local criteria to qualify. Many light-colored varieties of natural stone have been shown to lower a building’s or site’s “heat island” through their ability to reflect heat. Heat island refers to the concept of a building raising the average temperature of the area surrounding a building and site.
LEED Credits Sustainable Sites
LEED Credits 7.1 (non-roof) & 7.2 (roof)
SRI (Solar Reflectance Index)- calculated as “the ratio of the reflected flux to the incident flux.” Essentially, it is the ability of a material to reject solar energy.
1) Requires that at least 50% of the projects hardscaped area, to be constructed of a material with a minimum SRI value of 29.
2) Requires at least 75% of the roofing material to have a minimum SRI of 78 for low-sloped roofs and minimum 29 for steep-sloped roofs.
Alternatively, if a low SRI material is used, a credit can be earned if the weighted average roofing SRI is at least 75.