Use ASHRAE Standard 228 to see whether your buildings qualify as “zero net energy” or “zero net carbon”

Posted by Johann Nacario — May 3, 2023 — Global building technology society ASHRAE has released a new standard to measure zero net carbon and energy goals in buildings. ANSI/ASHRAE Standard 228-2023, Standard Method of Evaluating Zero Net Energy and Zero Net Carbon Building Performance, sets requirements for evaluating whether a building or group of buildings meets a definition of “zero net energy” or a definition of “zero net carbon” during building operation.

Standard 228 draws from ASHRAE Standard 105, Standard Methods of Determining, Expressing, and Comparing Building Energy Performance and Greenhouse Gas Emissions, among others, to address energy and carbon flows across a site boundary, their measurement, and their balance.

Keith Emerson, P.E., Life Member ASHRAE, chair of the Standards Project Committee 228, stated:

Achieving a zero energy building has been viewed by many as a difficult goal to meet, with unforeseeable roadblocks and differing guidance. Standard 228 provides a consistent method for determining whether new and existing sites have reached zero energy. We hope this standard will become a helpful resource for building professionals in strategic decarbonization planning.

Additional features of Standard 228 are as follows:

  • Allowances for sites that lack the opportunity to produce adequate renewable energy, while placing additional requirements on the use of external carbon and renewable energy in the calculation.
  • Defined calculation of energy in terms of source — a multiplier on the energy crossing the site boundary to include energy used or lost in extraction, generation and transit to the site.
  • The main energy calculation made in terms of annual average factors. Allowance is made for the calculation of individual hours where data is available.

Standard 228 does not apply to the establishment of building energy performance goals or limits; design guidance or design requirements; embodied energy of building materials and systems; and transportation to and from a building. The standard is also not intended to circumvent any safety, health, or environmental requirements.

To purchase ANSI/ASHRAE Standard 228-2023, Standard Method of Evaluating Zero Net Energy and Zero Net Carbon Building Performance, visit ASHRAE. Standard 228 has been published on continuous maintenance. A Standing Standard Project Committee (SSPC 228), chaired by Dr. Paul Torcellini, has been formed to update the standard through the publication of addenda or revisions to any part of the standard. Instructions for how to submit a change can be found on the website.