Earlier this month the U.S. Department of Energy announced a common definition for Zero Energy Buildings or what are also sometimes called ZEBs or Net Zero Buildings.

Why is this important?

According to the U.S. Department of Energy this is significant because:

“A broadly accepted definition of ZEB boundaries and metrics is foundational to efforts by governments, utilities
and private entities to recognize or incentivize ZEBs. A commonly accepted definition and corresponding methods
of measurement for ZEBs would also have a significant impact on the development of design strategies for
buildings and help spur greater market uptake of such projects.

The definition of ZEBs needs to include clear and concise language to be effective and accepted. Metrics and
measurement guidelines are required to allow verification of the achievement of the key elements of the definition.
The definition, nomenclature and measurement guidelines should address how energy consumption is measured
and what energy uses and types to include in its determination.300x250NetZeroEbook082815

In practice, actual projects seeking to verify zero energy should work to ensure no harm is done in the process
of achieving zero energy performance across other, non-energy-related considerations, such as water protection,
optimized comfort for low-load buildings, and comprehensive indoor air quality. While these considerations don’t
affect the definition of zero energy, it is important that in practice a design team ensures that other important
building considerations and values are not sacrificed in pursuit of zero energy.”

The U.S. Department of Energy didn’t just define Zero Energy Buildings but also took it another step further and defined the names of a collection of buildings that share energy. Without further ado here are the “official” definitions as laid out by the U.S. Department of Energy.

Zero Energy Building (ZEB)

An energy-efficient building where, on a source energy basis, the actual annual delivered energy is less than or
equal to the on-site renewable exported energy.

Zero Energy Campus

An energy-efficient campus where, on a source energy basis, the actual annual delivered energy is less than or
equal to the on-site renewable exported energy.

Zero Energy Portfolio

An energy-efficient portfolio where, on a source energy basis, the actual annual delivered energy is less than or
equal to the on-site renewable exported energy.

Zero Energy Community

An energy-efficient community where, on a source energy basis, the actual annual delivered energy is less than

This information was pulled from a recently released PDF from the U.S. Department of Energy titled “A Common Definition for Zero Energy Buildings“. I highly encourage anyone involved in LEED or any Green Building to download. It is a comprehensive document that does well beyond just supplying a definition. Here is the complete table of contents.

  • Introduction
  • Background
  • Goals
  • Methodology
  • Guiding Principles
  • Definitions
  • Zero Energy Building (ZEB)
  • Zero Energy Campus
  • Zero Energy Portfolio
  • Zero Energy Community
  • Nomenclature
  • Measurement and Implementation Guidelines
  • Boundaries
  • Energy Accounting and Measurements
  • Source Energy Calculations
  • Example Calculation for All Electric ZEB
  • Example Calculation for ZEB with Multiple Delivered Energy Types
  • Example Calculation for ZEB with Combined Heat and Power (CHP)
  • Using Renewable Energy Certificates (REC)
  • Renewable Energy Certificate – Zero Energy Building (REC-ZEB)
  • Using the terms “Zero Energy Building” and “Renewable Energy Certificate Zero Energy Building”

CONTRIBUTING EXPERT

imageDavid Clemen

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