Eco-friendly homebuilding starts at the building process itself
By Sarah Stanley
Builders and developers have an important role to play in preserving larger ecosystems. High consumption lifestyles and increasing populations have put additional stress on local and regional ecosystems and habitats. A 2018 report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystems Services (IPBES) notes that land degradation is often overlooked as an unintended consequence of economic development, and a significant contributor to climate change.
Biodiversity and ecosystem health are critical components of creating healthy, resilient, and sustainable homes and communities. Natural spaces help sequester carbon, clean the air and water, increase energy efficiency, and support wildlife habitats.
The U.S. Green Building Council’s (USGBC) LEED green building program outlines strategies for builders and developers to consider when starting construction. LEED v4.1 and the Sustainable Sites credit category is an important place to start. This latest version of the rating system includes requirements covering everything from reducing pollution from construction activities, to controlling runoff and protecting onsite storm sewer inlets or streams. Here are some sustainable site strategies teams should consider for their next green home project:
Project teams can reduce runoff and improve water quality by replicating natural hydrology. Historical conditions and undeveloped ecosystems in the region can also inform strategies for addressing water balance. For single family homes, the LEED v4.1 Rainwater Management credit encourages project teams to opt for one of two pathways. The first encourages teams to minimize the amount of stormwater that leaves a site and consider green infrastructure to replicate natural site hydrology. The second option outlines several requirements a project must meet for all designed landscape softscapes. It includes avoiding the use of invasive plants, and the use of turf in densely shaded areas and in areas with slopes of 25% or greater.
Rainwater management is an important benefit and plays a critical role when it comes to addressing climate risks, such as flooding. The El Camino Real Apartments project is a LEED Homes Award winner and an example. The apartments sit on a floodplain in Hatch, New Mexico, and a key consideration for the design was potential flooding issues. In the final design the project team, which included Cresline Buildings and Thomas Development, included a primary retention pond, numerous small detention ponds connected around the site, permeable landscape zones, and a finish-floor height above the 100-year flood level. The design process became a balancing act between resolving issues related to stormwater management and ensuring there was still space for enough units.
Heat Island Reduction
Heat islands can increase air and water pollution and greenhouse gas emissions, and at a personal level it can also lead to heat-related illness and mortality.
In LEED, the Heat Island Reduction credit for multifamily and single family projects encourages teams to consider green building strategies for at least 50% of roof or nonroof hardscapes. Strategies can include vegetative roofs, high-reflectance roofing and shading over paved areas including those that support energy generation systems, such as solar panels.
Creating a sustainable, healthy lifestyle for potential homebuyers requires project teams to leverage the natural spaces around the site. LEED’s Open Space credit requires that a project use at least 30% of the total site area for outdoor space or be located within a ½ mile of a publicly accessible or community-based open space. By preserving and creating outdoor spaces, projects can support biodiversity and wildlife habitat, and provide mental and physical health benefits.
In an effort to help project teams further address site sustainability, USGBC outlined synergies between LEED and the SITES rating system. SITES is modeled after LEED and takes a deeper dive into sustainable landscape development. Using the synergies outlined, multifamily projects pursuing LEED can also earn credits toward SITES certification. Currently, there are more than 180 registered and certified SITES projects in 12 countries and 37 U.S. states plus Washington, D.C.
Sustainable site development is often overlooked, but an increasingly important way for builders and developers to demonstrate a commitment to human and ecosystem health. As more communities focus on methods for creating healthier places for people while continuing to address climate risks, sustainable site strategies will be an invaluable tool.
Sarah Stanley is the Director of Communications for the United States Green Building Council. To learn more, visit usgbc.org