Leverage your DDx Data to benchmark the National Zero Emission Building definition
- Eana Bacchiocchi
By the AIA DDx subgroup
This past June, the White House and Department of Energy published the first part of the National Definition of a Zero Emission Building. Part 1 of this definition includes three main requirements that guide teams toward a zero operational emission building design. The AIA supports the use of this definition across the industry to help standardize the way architects and designers talk about and understand zero emission building design.
The AIA 2030 Commitment launched more than ten years ago to support designers in targeting and tracking progress toward zero emissions design. Annual reporting by Commitment signatories in the Design Data Exchange (DDx) platform has historically focused on reduction in energy use intensity but is shifting toward a carbon emission approach. As firms input project data for tracking, teams can leverage the DDx to benchmark projects against the national definition throughout design. As the project transitions into operations, owners will be able to track annual utility data in Energy Star Portfolio Manager for existing building compliance. The AIA is currently exploring partnerships to add features in the DDx that would provide a direct link with Portfolio Manager that would further support and simplify tracking compliance with this new definition.
A project recorded in the DDx can consider itself well positioned for compliance with the new zero emission building definition if the entry demonstrates sufficient reduction before the addition of renewables, has no onsite combustion recorded in its fuel sources, and is then fully offset by renewables.
How to use the DDx to benchmark your project for compliance with new federal definition of a zero-emission building, based on each of the three parts:
Design to be Energy Efficient
Record the modeled predicted energy use intensity (pEUI) by fuel source for the total site energy demand of your building in the DDx.
For new construction and major renovation whole building projects, demonstrate a gross pEUI reduction 10% (or greater more efficient than the most recent published model energy code. Currently this would be met with IECC 2021 at a 50% base efficiency, plus an additional 10% efficiency. This means any project following 2021 with no less than a 60% reduction meets the intent of the definition.
Alternatively, at the bottom of the design phase data input page, there is a field to record the baseline EUI of the project’s model code energy model. This field can be completed, and the project team can manually check the estimated gross pEUI reduction before renewable offsets. If the reduction is greater than 10%, then the project is positioned to meet this criteria.
As newer model codes and standards such as IECC 2024 and ASHRAE 90.1-2022 are published, these become the new published model code to be used as the basis of the calculation. The 2030 Commitment program hopes to have those estimated reductions in the DDx before the end of the calendar year.
Free of Onsite Emissions from Energy Use
To confirm the building is all electric without onsite fossil fuel combustion, report energy by fuel sources in the DDx. This is done in lieu of recording a blanket pEUI value.
Per the definition, no onsite combustion is allowed within the building except for emergency back-up power. This prohibition includes cooking, equipment, and other internal uses.
District Energy sources can contribute to compliance, but only if they operate as a zero-emission facility as well. District plants that use fossil fuel for generation pass their carbon footprint downstream to the users and disqualify them from compliance.
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Demonstrate full onsite or purchased offsite renewable energy offset by recording the offsets in the DDx. Full credit for offsets only works if you first entered fuel sources.
The result of adding renewables to an all-electric building should be a minimum Net Predicted EUI of 0 and a Net Operational Carbon Intensity of 0.
Requirements for additionality or restrictions between local RECs or national RECs shall be dictated by the selected compliance path in the definition. Each path is a little different, so be sure to review them in the context of your project. Two of the four standards require that purchased offsite renewables indicate a date of service.
EO 14057 – Qualifying generation or purchased offsets in the form of energy attribute certificates (EACs) must have been placed into service after Oct 2021.
ASHRAE Standard 228-2023 sections 8.3-8.6 – This standard provides calculation methodology and offset guidance for new and existing buildings. The standard requires renewables within the local grid, and purchased for a minimum 15-year contract, and considering the discount factors in the chart for purchased offsite generation based on type and year of start of service for the renewable system.
EPA Green Power Partnership – Partner with a renewable facility with resources that have come online in the last 15 years. A range of eligible products qualify include onsite generation, green power programs purchased through utilities, etc.
Green-e Renewable Energy Standard - This standard defines the minimum requirements for renewable electricity and renewable energy certificates (RECs) sold under the copyrighted Green-e® Energy certified labels. The standard was created to promote high quality renewable electricity development and generation. To qualify for the Green-e label, “Only new renewables are eligible to meet Green-e® Energy standards. The term “New Date” is defined to include any eligible renewable facility beginning operation or repowered after the dates” as indicated in the table in the standard. In theory, if purchasing Green-e certified RECs, this has already been vetted on your behalf.
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