A zero net energy (ZNE) building is a home or commercial building that on average produces as much energy as it uses, achieved through energy efficiency and renewable technologies. The ZNE concept has captured the imagination of the building design and clean energy communities. Now, policymakers, businesses, and a broader segment of the general public are showing an increased interest in ZNE as a means to reduce building operating costs and environmental impact while addressing energy supply challenges. The burgeoning interest in ZNE is reflected in the growing number of ZNE-related targets, goals, and certifications: the American Institute of Architects’ 2030 Challenge, California’s ZNE goals for residential and commercial new construction, and DOE’s Zero Energy Ready Homes Program are notable examples.
How do we turn the buzz surrounding ZNE into real advances on the ground? To meet goals for ZNE construction by 2030, we need to put in place building codes that establish effective requirements for ZNE performance for most building types by 2030.
In our new paper, Energy Codes for Ultra-Low-Energy Buildings: A Critical Pathway to Zero Net Energy Buildings, we take a look at the current state of zero net energy buildings and explore what it will take to make ZNE construction the norm as of 2030. We place a particular emphasis on building energy codes. Existing technologies and construction practices can deliver ZNE performance for many building types and climates, while allowing a wide range of equipment and design options to meet the functional and aesthetic needs of most construction projects. And experience shows that it can be done cost-effectively. As the market for ZNE grows, these options will continue to expand and the economics will become more attractive.
Building energy codes have a role to play in facilitating the move to ZNE buildings. As advances in construction practices and building components and systems are proven out, we can strengthen the building codes so that higher levels of building efficiency become standard practice. To do this, we need to modernize our approach to building codes to reflect the evolution in construction practices, changes in building energy use patterns, and new goals we've established for our building stock.
Priority changes include
- expanding the scope of codes to capture all building energy uses (including growing plug and process loads),
- addressing the energy savings available in building systems rather than only focusing on individual components or products, and
- shifting the focus from building design to actual building energy use through adoption of outcome-based codes.
Effective codes for ZNE buildings will ensure ZNE performance post-occupancy by considering the impact of building occupants and operators and incorporating future-proofing measures to avoid the built-in obsolescence common in buildings today.
Getting our codes to ZNE by 2030 will be challenging, but much can be done to ease the transition and increase the likelihood of achieving this goal. Complementary policies, targeted research, market transformation and related activities, and the coordination of efforts and advocacy can establish the foundation for ZNE while providing energy savings and related benefits in the interim. ACEEE is committed to working with the buildings industry, policymakers, the efficiency community, and others to further the conversation on ZNE and make ZNE goals a reality. As part of this commitment, ACEEE is a community partner in the Getting to Zero National Forum to be held in Washington, D.C. on February 1-3, 2015. Co-hosted by New Buildings Institute, the National Association of State Energy Officials, and Rocky Mountain Institute, the forum will bring these groups together to share best practices for successful ZNE projects and policies and foster greater collaboration on opportunities for ZNE to transform the built environment. Hope you can join us and be part of the dialog.