LEED v4 News: Updates to Water and Sites
March 19, 2019
LEED v4 encourages a more integrative process
The Leadership in Energy and Environmental Design (LEED) was launched in August 1998 by USGBC with a mission to promote sustainability-focused practices in the building and construction industry. Since then, LEED has evolved over the years to more accurately represent and incorporate emerging technologies and latest government policies and standards. The newest generation of LEED green building, LEED v4 was unveiled in 2013.
LEED v4 builds on the fundamentals of previous versions of LEED while taking a slightly different approach for achieving green-building goals. LEED V4 is more aggressive than the earlier version and encourages the use of the integrative process which requires all team members actively be involved during a project and work together to optimize the building performance and meet the project sustainability goals. The familiar credit categories have also changed. It has also been designed to provide a platform for adaptation for global growth by making it flexible enough to be used on a wide scale that is not limited by type or location of the project.
In LEED v4, several credits from LEED 2009 have been consolidated and smoothed out, and new credits have been included. One of the most critical changes to the LEED v4 green building rating system is the new water efficiency credit structure.
LEED v4 New Water Efficiency Credit Structure
Building on lessons learned from LEED 2009, the LEED v4 rating systems requires projects to adopt a comprehensive approach to water management and consider water use throughout the building life cycle. The rationale behind LEED v4 water requirements is connected to accelerated water scarcity and compromised water quality. Emphasising an “efficiency first” approach, LEED v4 requires the projects to first focus on water use reduction strategies and then to consider alternative sources of water. Water metering for the entire building and associated grounds is introduced as a prerequisite in LEED v4, to ensure the buildings can monitor their water use to identify opportunities for water savings.
The LEED v4 water efficiency section introduces three prerequisites and takes into account indoor use, outdoor use, specialised uses and water metering efforts for credits. LEED v4 measures all sources of water related to a building, including cooling towers, appliances, fixtures, fittings, process water, and irrigation, and rewards projects for achieving potable water reduction milestones above the baseline. Net Zero Water has developed some sample designs for these applications that you can download here.
In LEED v4 projects have the opportunity to earn up to 14 credit points through the implementation of a comprehensive water harvesting and reuse strategy, such as a rainwater harvesting system. The collected rainwater can be used as an alternative source of water for non-potable applications such as toilet/urinal flushing, irrigation, or vehicle washing to minimize indoor and outdoor water consumption, or serve as cooling tower makeup water. When integrated into project design, the rainwater harvesting system can also help to achieve the new Rainwater Management credit goal by reducing the site runoff volume.
To learn more about the LEED V4 Updates to Water Efficiency Credit Category, Sloan has published a great article that comprehensively explains details of water efficiency credit categories and available points in LEED 4.