MassCEC has provided a $200,000 grant to the Northeast HERS Alliance (NEHERS) to establish a baseline for embodied carbon in new homes in Massachusetts. And National Grid and Eversource have added another $30,000 so that we can include MEP in this study (more below).
We are asking raters to assist in modeling the embodied carbon of 100 new homes in Massachusetts. Raters will be expected to complete a minimum of 5 projects and will receive compensation of $500 for every model that is submitted.
To facilitate accurate tracking of embodied carbon, our project team has developed an intermediary worksheet that bridges the data from Ekotrope into the Building Emissions Accounting for Materials (BEAM Estimator) tool. This integration tool is designed to help raters efficiently transfer and manage data outputs from Ekotrope as they work with BEAM, focusing on both embodied and operational carbon targets. We recognize that this process is new for many and we are committed to making it as seamless as possible.
As a part of the study, you are invited to take part in a brief training session. This session will cover the use of the integration worksheet and emphasize the importance of embodied carbon as a key consideration for raters when advising builders during the design and construction process.
We appreciate your consideration.
PROGRAM DESCRIPTION:
In collaboration with MassCEC, the Northeast HERS Alliance has been contracted to develop a 100-Home Study to provide insight into the current embodied carbon levels in 100 new homes in Massachusetts. The goal is to establish a baseline for embodied carbon in new homes in the state for potential inclusion in incentive programs and code development.
As a key part of this baseline exercise, the project team is working to simplify the process for HERS raters to track embodied carbon emissions by executing a comprehensive workflow to easily integrate data from existing Ekotrope models into the BEAM tool that measures embodied carbon. This integration will automate much of the process, enabling HERS raters to simultaneously focus on both embodied carbon and operational carbon targets. By streamlining this workflow, raters can guide builders, developers, and homeowners on how to value engineer projects, selecting the best combination of carbon reduction strategies at the lowest cost. Future funding phases could leverage this completed workflow to facilitate the full integration of embodied carbon calculations directly into RESNET Accredited HERS Rating Software Systems.
HERS raters have long been the benchmark in operational analytics with the HERS Index. Now, by integrating the carbon intensity of materials, they are ready to advance into the next phase of integrative design to provide a comprehensive view of Carbon Use Intensity by combining the insights from the RESNET HERS Index, the CO2 Index, and this new focus on the carbon footprint of building materials.
WHAT IS EMBODIED CARBON AND WHY SHOULD WE MODEL IT?
Embodied carbon refers to the emissions that arise from products used to construct and renovate buildings. These emissions occur from the early stages of harvesting raw materials and manufacturing products to the end of life disposal.
It is only in the last decade that embodied carbon emissions have started to be counted, and studies are showing that they are surprisingly large, often outweighing operational emissions by 5-50 years. This means it is critical to measure and report embodied carbon as we work to decarbonize the homebuilding sector.
Studies of embodied carbon using the BEAM tool from Builders from Climate Action shows that average embodied carbon for new homes can be 30-40 tons of CO2e and around 200 kg CO2e per square meter of conditioned floor area. At these rates, the embodied carbon emissions from the US homebuilding sector would total around 35 million metric tons per year, as much as the entire economies of countries like Denmark and Ireland.
Source: The Hidden Climate Impact of Residential Construction, RMI, 2023
These studies also demonstrate that it is possible for the homebuilding sector to achieve 10-20% reductions in embodied carbon with simple, no-cost material substitutions and that reductions of up to 50% or more are feasible and affordable.
As HERS raters help their clients achieve ever-lower HERS scores, the importance of embodied carbon grows as seen in the graph below.
As part of the training for participants in this study, we will provide an in-depth understanding of embodied carbon and how it is calculated to provide you with a robust understanding of the topic.
MECHANICAL, ELECTRICAL AND PLUMBING (MEP):
We are excited to announce that with additional funding from MassCEC, our study will now include a dedicated section to estimate the embodied carbon for Mechanical, Electrical, and Plumbing (MEP) systems. Until now, MEP components have not been part of benchmarking efforts. To support this new focus, the project team has been working to develop a separate MEP tab that will be included in the integration tool. Thanks to the substantial research conducted by Jacob Racusin of Builders For Climate Action, we can now incorporate MEP into our 100-home study.
PARTICIPATION REQUIREMENTS:
Expectations
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Raters will be expected to participate in a 3 part embodied carbon workflow training. This training will take approximately 4.5 hours and be broken down into one self-paced module and two live synchronous modules. This training will walk raters through the basics of embodied carbon, how to import their energy models into our worksheets and how to model material carbon emissions in BEAM.
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Raters can expect to spend 1.5- 2hrs modelling each building, possibly longer on your first modelling project. Raters might also be asked to track their time modelling so that a more accurate estimate can be expected in the future. Modelling support will be provided through out the process.
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Raters are expected to complete a minimum of 5 home evaluations for this study
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Raters will receive $500 for every model they submit to the study
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CEUs for Raters- Upon completion of both training and project modelling, raters will be eligible to receive CEUs. The number of CEUs is being discussed.
Project Selection Criteria
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All Homes must be constructed in the state of Massachusetts
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The project must be registered with the RESNET Registry
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The project has a sketch-up model (preferred). If there is no Sketchup, then PDF markups should be shared with QA, from Bluebeam, Adobe, or a similar markup tool
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Homes must be permitted after January 1, 2023, but before July 1, 2024 (This aligns with the Stretch 2024 Code change in Massachusetts)
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If the project has a garage, an unconditioned garage would be preferable. Garages can be either attached or detached
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Maximum single home area - None
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Both Single detached and row houses qualify. Row houses must be side-by-side design.
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No Renovations or additions
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Jobs not registered or completed or with significant missing information do not qualify for the study.
Maximum of (20) homes to be multifamily to align with state averages for Low Rise Residential. Minimum of (10) homes to have garages, either attached or unattached.
PROJECT PARTNERS:
RESOURCES:
RMI Hidden Emissions Report
RMI - HomeBuildersCan
NEHERS
Builders for Climate Action- BEAM tool
Carbon Leadership Forum
MASS CEC 100 Home study
MASS CEC Embodied Carbon