by Brianna Crandall — September 21, 2015—On September 17, the U.S. Department of Energy (DOE) reached a significant milestone in bringing the building community together by releasing a common definition and guidelines for a zero energy building, or what is also referred to as a “net zero energy” or “zero net energy” building.
After leading an extensive stakeholder engagement process over the past year and a half, the Energy Department released its findings in the recently published A Common Definition for Zero Energy Buildings, which states that a Zero Energy Building is “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.”
This definition also applies to campuses, portfolios and communities. In addition to providing clarity across the industry, this new DOE publication provides important guidelines for measurement and implementation, specifically explaining how to utilize this definition for building projects.
In collaboration with the National Institute of Building Sciences (NIBS), DOE initiated a process last year to work with a large, diverse set of building industry stakeholders to develop its common definition for what it means to be a zero energy building. Thousands of project teams throughout the country are looking to push the envelope and achieve a zero energy building.
In fact, the number of zero energy buildings doubled from 2012 to 2014 across 36 states, according to the [New Buildings Institute (NBI). The growth of zero energy buildings has highlighted a lack of clarity and consistency across the industry on key definitional issues that increasingly were the source of market confusion, underscoring the need for DOE to help develop a commonly accepted, clear and concise definition and approach.
Generally speaking, a zero energy building produces enough renewable energy to meet its own annual energy consumption requirements, thereby reducing the use of non-renewable energy in the building sector, explains DOE. There are a number of long-term advantages of buildings meeting this goal, including lower environmental impacts, lower operating and maintenance costs, better resilience to power outages and natural disasters, and improved energy security.
Reducing building energy consumption in new building construction or renovation can be accomplished through various means, including integrated design, energy efficiency retrofits, reduced plug loads and energy conservation programs. Reduced energy consumption makes it simpler and less expensive to meet the building’s energy needs with renewable sources of energy.
By clarifying what it means to be a zero energy building, this definition will help more building owners determine if developing a zero energy building is right for them, and building owners, facilities managers and project teams can now better focus their effort on implementing strategies to improve the performance of their buildings.
The definition and report were welcomed by such major stakeholders as the U.S. Green Building Council (USGBC), the New Buildings Institute (NBI), the American Institute of Architects (AIA), the National Association of State Energy Officials (NASEO), the U.S. Affiliate of the International Building Performance and Simulation Association (IBPSA-USA), and global building technology society ASHRAE.
A Common Definition for Zero Energy Buildings is available for download from the DOE Web site.
