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BASCL's Response to the LEED v4.1 Waste Credit Changes

General Overview:

While the new LEED v4.1 language for Construction and Demolition Waste Management (C&DWM) credit (based on Nov 2020 addenda) brings positive changes such as emphasizing waste prevention and simplifying the overall credit language, the following changes are concerning and therefore our Bay Area Sustainable Construction Leaders (BASCL) community of general contractors wanted to bring our thoughts to the attention of the MR TAG group and other USGBC team members.

The MR Tag group that met to define the revised language included just two general contractors out of 23 total contributors. Given a mission of USGBC is market transformation, we hope the below content provides additional considerations from us General Contractors.

Items of Concern:

Diversion Rate Thresholds: New LEED v4.1 language for C&DWM credit, emphasizes waste prevention, and unlike previous versions it does not offer options for projects for waste diversion. The single path option for waste diversion awards 1 LEED point to projects that divert at least 50% of the total C&D materials from landfills and incineration facilities. Our group believes that achieving at least 50% diversion for C&D materials is easily achievable for most of the common construction projects. Average recovery rates without ADC for registered waste sorting facilities in the City and County of San Francisco are typically over 50% although all these facilities are heavily regulated and third-party certified. Our group observes even higher recovery rates in regions that are not regulated. Therefore, our group concerns that this single path option for waste diversion with 50% diversion threshold might cause many projects to achieve a “free” LEED point with the use of a single commingled waste container throughout the project and discourage project teams for planning early for higher waste diversions. We acknowledge it is more difficult for RCI facilities to achieve 50%, versus non-RCI facilities would breeze by. We recommend an Option 2 for Diversion, with the requirement of 75% or third-party verified RCI facilities for 2 total points.

Discouragement of On-site Source Separation: Although waste reduction is the primary goal of the construction waste management credit in LEED, if a project team is undecided on the pursuit of Option 1 or 2, source separation can increase the ability to reduce overall waste contributing to end of life. Source separation allows project teams to identify materials that can be donated, salvaged, and reused further reducing the overall waste generated from construction. In addition, source separating waste can lead to opportunities for recycling materials such as metal, concrete, and carpet. Metal and concrete recycling specifically greatly reduce the overall environmental impact of creating virgin materials and should be encouraged. Eliminating the requirement for source separating material streams also discourages early planning on the demolition and construction team for ongoing waste management throughout the project. We recommend identifying at least 2 separate material streams in order to comply with Option 1 of this credit.

Unrealistic Pound/SF Thresholds: While maximum lbs/sf of waste thresholds paths have been increased in comparison to LEED v4, they are still not achievable for many NC projects, yet do seem feasible for TI projects; and therefore, this change might lead many project teams to ignore the strategies for waste prevention and focus only on achieving Option 1 – Waste Diversion. The data collected within the following table as provided by USGBC [Figure 1], seems unrealistic based on our own analysis within the extremely progressive Northern California Bay Area region [Figure 2]. San Francisco requires LEED certification for all NC projects, and therefore our numbers aren't just traditional projects where we weren't trying to reduce waste, yet ones already trying to push for high waste goals. We recommend increasing the lbs/sf metrics used to generate the proposed thresholds for NC projects to a more realistic value.

Not in Support of Transparency: The previous LEED language encouraged project teams to use an RCI or 3rd party certified facility to recycle mixed C&D debris. Although projects can still get an additional Innovation point through “Verified Construction & Demolition Recycling Rates” by utilizing RCI-certified waste sorting facilities, incorporating a point for using RCI-certified facilities into the MR Construction Waste Management credit better incentivizes waste facilities to participate. When the “Verified Construction & Demolition Recycling Rates” remains in the innovation category, it is left to compete with more simple and less impactful credits, incentivizing project teams to achieve all innovation points by other means.

We fully support the need for transparency in the recycling rates. As Bay Area Sustainable Construction Leaders, we have committed to support RCI and 3rd party certified recyclers when available knowing that the recycling rates will be much lower than a non-certified facility. However, the proposed credit language doesn’t distinguish between achieving the diversion rate and using a certified recycler. The language change misses on the opportunity to push for market transformation by removing a powerful incentive for recyclers to pursue a 3rd party certification. We recommend RCI utilization should be included in Option 1 or 2 language, not within the exemplary performance section.

Waste Reduction is a Design Issue More So Than a Contractor Issue: Whereas historical LEED wording has been considered a contractor credit, achieving a lower total waste footprint on a project is more a result of deliberate reuse through design and owner reuse decisions than careful contractor planning. With building element reuse being a highly personal design decision, the existence of a single LEED waste point is unlikely to sway an owner or designer into choosing building component reuse. In addition, reuse is incentivized in the Sourcing of Raw Materials Credit and earns points in Life Cycle Impact Reduction. Instead, the criteria as it is currently written has a very real risk to backfire and increase the amount of C&D material going to landfill by disincentivizing above-and-beyond diversion practices, like source-separation.

Ultimately, circular design principles are the end goal – but with those elements just now getting incorporated into designs and with an average building lifespan of 50 years, the deconstruction benefits will not be realized for many years to come. We recommend Design for Circularity to have increased weight in the LEED rating systems process, and a framework should be setup for contractors to deconstruct later on, and waste prevention should be part of this designer credit.


This letter does not serve as an attempt by the contractor community to offload waste minimization efforts from the contractor’s shoulders. On the contrary, the Bay Area SCL is committed to improving waste handling transparency and diversion practices. However, with the weight limits being difficult to achieve, there is a very real risk that contractors will write off the 2nd point and divest energy away from source-separating in order to exceed a 50% diversion rate. We look forward to collaborating with the USGBC and serving as a resource for the development of the Waste Management credits.



[Figure 1]

[Figure 2] *This data comes from four general contractors, and a total of 41 San Francisco based jobs.

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