What is a Zero-Energy Building? / by Jon Gardzelewski

The simple question What is a Zero-Energy Building? occasionally triggers some controversy.  It's good to have common definitions.

The US Department of Energy (DOE) has a new 22-page report entitled A Common Definition for Zero Energy Buildings.

They define a Zero Energy Building (ZEB) as:
"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."

Of note:

  • The term "energy-efficient building" is not defined. 
  • Wood and wood pellets are considered delivered energy, and therefore treated like gas or oil (unless harvested on-site).
  • The report endorses Conversion Factors.  For example, you can overproduce electricity to get credit for delivered natural gas consumption at a rate of about 3-to-1.

The controversies will certainly continue.  Allison Bailes provides some commentary on the report here.

Related: Mother Earth News article, "What Is a Net-Zero Home?"