USGBC recently released LEED V4.1 BD+C and opened the beta registration in January. The new version is touted as bigger, stronger, and bolder. The highlights include 3 major changes, two of them in Energy and Atmosphere (EA) related credits:
- The energy metrics include both cost and greenhouse gas emissions (a first for LEED).
- An upgrade to ASHRAE 90.1-2016.
- Applicable and achievable credit requirements throughout the rating system:
- Rainwater Management requirement with a lower minimum percentile storm events and added guidance for zero-lot-line projects.
- Renewable Energy credit that addresses diverse methods of renewables procurement and evolving global renewables markets.
- Restructured Materials and Resources credits that include options acknowledging efforts at varying levels, bridging the gap from where the market is currently to the goals identified in LEED v4 and carried into LEED v4.1.
The following will highlight a few of the improvements and revisions related to energy, atmosphere and daylight credits that affect building design specifically. As a member of the Technical Advisory Group in EA, I have been involved in developing EA credits for LEED v4.1 which have made significant improvements and revisions in the recent version. In the Energy Optimization Credit, LEED V4.1 BD+C will jump directly to ASHRAE 90.1 2016 instead of taking an incremental upgrade to ASHRAE 90.1 2013 from ASHRAE 90.1 2010 (LEED V4 requirement). This change responded to the market needs and energy code development, and while Texas is often perceived as behind the curve in sustainability and energy efficiency, it actually has a very progressive energy policy. For example, the City of San Antonio has adopted and applied ASHRAE 90.1 2016 / IECC 2018 as a code requirement.
Another major revision includes the energy metrics. For a long time, LEED only used energy cost to measure performance, although recently, it has allowed an ACP (Alternative Compliance Path) that allows the project to use different metric systems (see https://www.usgbc.org/credits/eapc95v4.) There were criticisms that LEED does not respond to the climate change issue and it is not progressive enough. LEED V4.1 responded by including both energy cost and greenhouse gas emissions. The inclusion of the cost will ensure that the metrics still consider the market demands and grid congestion. Furthermore, most owners are more familiar with cost metrics than with global warming potential or even Energy Use Intensity (EUI). Including energy cost also ensures that the metrics still give points to energy efficiency in buildings, regardless of whether the project is located in the clean grid. As you can see in the diagram below, the credit splits the points into two categories, such as cost and greenhouse gas emissions. This is combined with renewable energy credits and also rewards more points for buildings that achieve Net-Zero energy or carbon neutral buildings.In renewable energy, LEED V4.1 BD+C has 5 different categories and different point levels that the project can achieve. The new version shows LEED’s commitment to support different options in renewable energy and to reduce greenhouse gas emissions in the building. Using the current metrics, the project can achieve up to 5 points and 1 exemplary performance credit, although it requires the project to show a longer period of commitment for the renewable energy that will be used.
For daylight credits, LEED V4.1 BD+C also provides key updates. It lowers the requirements to achieve the daylight credit point for option 1 and option 2, therefore, more projects are likely to pursue and obtain this credit. As I often mention during my presentations and during project reviews, the LEED V4 BD+C daylight credits are difficult to achieve if the project is more than 1 story and has a thick massing building design. LEED V4 will encourage more projects to implement daylight design driving the use of daylight simulation to drive the design instead of to validate the design only.
While maintaining the structure of the LEED V4 BD+C, LEED V4.1 BD+C provides stronger and bolder sustainability metrics to assess the building. The updated requirements show that USGBC is responding to market demand and public feedback. If you want to learn more about LEED V4.1 BD+C, you can download the draft version and credit library at the following links: https://build.usgbc.org/bdc41 and https://www.usgbc.org/credits/new-construction/v4.1