This credit rewards projects that implement the construction and demolition waste management (CWM) plan developed in the corresponding Construction and Demolition Waste Management Planning prerequisite. Project teams have two options for credit achievement—either diverting waste from the landfill or reducing overall waste generated. Details on each option are outlined below.
Option 1: Diversion percentages with a new twist
Similar to LEED 2009, Option 1 focuses on diverting construction and demolition waste from landfills by finding alternatives, including recycling or salvaging (via reuse on site, donation for reuse on another site, or resale).
The credit requires teams to divert both a percentage of overall waste and a certain number of material or waste streams, giving two options for compliance. Path 1 requires 50% diversion of the total construction and demolition debris and at least three material streams. Path 2 requires 75% diversion and at least four material streams.
What are material streams?
The LEED Reference Guide defines streams as flows of materials coming from a job site into markets for building materials. The online LEED Reference Guide video “Defining Waste Streams” provides additional information and states that a waste stream is defined by where the waste goes.
Typically a single material goes to a single waste stream; however, there are cases where a single type of material could go to multiple waste streams and conversely, where multiple materials go to a single waste stream. An example of two waste streams for a single material type would be wood waste that is sent to both a power generation facility as fuel and to local building supply to be reused. An example of multiple materials counted as a single waste stream would be crushing site-separated asphalt, concrete, and masonry together for aggregate, which is considered onsite waste diversion.
An easy way to categorize your streams is to focus on the heaviest waste or the waste that generates the most volume. As a best practice, a material stream should constitute at least 5% by weight or volume of total diverted materials.
Onsite separation vs. commingled collection for diversion
Teams must include collection and sorting methods as part of their CWM plans developed for this credit’s corresponding prerequisite. Depending on what is appropriate, projects may use a combination of onsite separation and commingled collection. In addition, teams may consider other waste stream diversion tactics like deconstructed materials sent to reuse markets, reuse of deconstructed materials, and take back programs from manufacturers.
For onsite separated ("source separation") materials, each type of material sent to a separate recycling facility counts as single stream. If, however, a single material is being diverted to several streams, each stream is counted separately. An example of two waste streams for a single material would be wood waste that going to a power generation facility as fuel and to local building supply to be reused.
To count toward this credit, commingled recycling facilities must be able to provide project-specific diversion rates or an average diversion rate for the facility that is regulated by the local or state authority. Visual inspection is not an acceptable method of evaluating diversion rates.
If the commingled recycling facility can track and produce documentation of specific materials recycled for your project, you can count commingled waste as multiple waste streams. Otherwise, commingled waste that is the average diversion rate for a regulated facility is counted as a single waste stream regardless of how many different materials are included. The average recycling rate for the facility must exclude ADC.
Alternative Daily Cover (ADC) is out
In a big change from previous versions of LEED, alternative daily cover (ADC) no longer qualifies as diversion. Any materials that are used for ADC must be counted as landfilled and your CWM plan must account for this.
Land-clearing debris and hazardous materials are still out but must be accounted for
Land-clearing debris materials that are natural (like rock, soil, stone, and vegetation) are not considered construction, demolition, or renovation waste. Consequently, teams should not include these materials in their calculations, although their CWM plans must account for these materials.
Similarly, teams must document the safe removal and disposal of hazardous materials in their CWM plans but exclude these materials in their calculations.
Incineration can be considered diversion in certain cases
Incineration can be diversion, but only if reuse and recycling methods are not readily available in the project’s location and a team can demonstrate they exhausted these strategies before sending waste material to energy facilities. In those cases, waste-to-energy incineration may be considered diversion and it must be included in the CWM plan. Teams must follow European Commission Waste Framework and Incineration Directives and the waste-to-energy facility must meet the applicable European standards based on fuel type.
Other waste diversion tactics
Deconstructed materials can be donated to charity or sent to another project site. Much like commingled waste, donation also counts as a single waste stream unless the receiving organization can verify and track the individual materials that are donated. This is another example of a multiple material types constituting a single waste stream when additional documentation is not available.
For deconstructed materials that are reused onsite, no distinction is made between whether the materials are serving their original function or not. In this case, each material reused onsite for each purpose counts as a single waste stream.
Take back programs are offered by product manufacturers who will accept shipments of materials removed during renovation and/or purchased overruns of their products. This type of waste stream is defined by the specific material type. For example, you would have two distinct waste streams if you had carpet sent to a take back program from a carpet manufacturer, and ceiling tile sent to a take back program from a ceiling tile manufacturer.
Diversion calculations can be by weight or volume
Similar to LEED 2009, teams can calculate the diversion rate by weight or volume as long as they are consistent. The diversion rate is calculated by dividing the total waste diverted from the landfill by the total waste generated by the project and multiplying the result by 100.
Option 2: Source reduction is a viable option
LEED v4 offers a new alternative to diversion: source reduction.
Option 1 will be fairly familiar to teams who worked on LEED 2009 projects and aside from defining material or waste streams should be fairly straightforward to document.
As an alternative to diversion, Option 2 will require teams to think about and plan for not generating waste in the first place, which is a new way of dealing with construction waste reduction for LEED. Option 2 directs teams to reduce total waste material and not generate more than 2.5 lbs/ft2 (12.2 kg/m2) of the building’s floor area.
Prefabrication, modular construction, or incorporating standard material lengths or sizes into the project’s design can all help reduce waste for this path to the credit. To get the most benefit, this option requires teams to plan for source reduction during design and implement it during construction.
Before using Option 2, teams should estimate the amount of waste for the project to determine if the performance threshold is realistic. If viable, teams should address the use of source reduction in their construction waste management (CWM) plan developed for the corresponding prerequisite to this credit.
Calculating total waste reduction for Option 2
Teams need to total up all construction and demolition waste generated including all offsite salvaged materials, all recycled materials, all landfilled material, and all incinerated materials. (Teams should not include materials reused onsite, which do not count as waste for Option 2.)
As Option 2 is written, this total needs to be provided by weight. As the LEED v4 Reference Guides for BD+C and ID+C do not include solid waste conversion factors tables, teams may want to utilize Table 2: Volume-to-Weight Conversation for Construction and Demolition Debris for the Construction Waste Management credit in LEED BD+C: Multifamily Midrise in the Credit Library as a resource.
Waste per area is calculated by dividing this total by the project’s gross floor area and multiplying the result by 100.
Can I achieve Exemplary Performance for this credit?
Yes—teams must achieve both Option 1 (either Path) and Option 2.
Is it achievable? Maybe. Projects that plan ahead, and that have good construction recycling infrastructure and limited landfill opportunities will be more likely to achieve this. Teams will need easy access to haulers who provide onsite separation or commingled collection with project-specific documentation to meet the Option 1 side and identify three or four unique material streams. However, teams will really have to put effort into planning for and documenting the source separation side (Option 2), which will require a new way of thinking about not generating waste in the first place. Larger projects will have an advantage over smaller ones due to the ability to spread the waste out over a larger square footage. Either way team it will all come down to the final tally of construction waste generated.