by Shane Henson — March 14, 2012—As more American building owners and financiers begin to take note of the many cost and sustainability benefits zero energy buildings provide, we can expect to see an increase in these types from sunny California to snowy New York state, says a new report released by the New Buildings Institute (NBI) and the Zero Energy Commercial Building Consortium (CBC).
The report, Getting To Zero 2012 Status Update: A First Look at the Costs and Features of Zero Energy Commercial Buildings, examines the number, location, costs and design strategies of various types of zero energy commercial buildings (ZEBs), as well as zero energy-capable (ZEC) buildings, which are energy efficient enough to be zero energy, but have not taken the final step of on-site renewable generation. It is the most comprehensive look at the state of zero energy commercial buildings to date, say both organizations.
Key report findings include:
- ZEBs have been successfully built in most climate zones of the United States.
- The majority of ZEBs to date are small or very small buildings, however, there are increasing examples of larger and more complex buildings. Many of the earliest examples are academic buildings or environmental centers—in effect, demonstration buildings, sometimes with low occupancy levels. More recent buildings include office buildings, K-8 schools and a credit union.
- ZEBs are constructed using readily available technology. An integrated design approach with careful attention to building site and layout, envelope, mechanical systems, and electrical systems is critical to achieve the high levels of energy efficiency. Unique or experimental systems are infrequently used to reach net zero goals, but the emergence of new technologies will be a factor in the expansion to more building types.
- Modeling studies indicate costs of 3% to 18% for energy efficiency features, depending on building type, size, climate and other variables. Reported incremental costs are only available from a few ZEB projects, making conclusions or trends difficult to derive from the limited information available. However, the few reported ZEBs appear to show lower overall incremental costs than modeled estimates, possibly due to positive trade-offs with other features in the design and construction process. Those costs range from 0% to 10%.
- The majority of ZEBs to date are small or very small buildings, however, there are increasing examples of larger and more complex buildings. Many of the earliest examples are academic buildings or environmental centers—in effect, demonstration buildings, sometimes with low occupancy levels. More recent buildings include office buildings, K-8 schools and a credit union.
The report also summarizes recommendations that would encourage additional development of ZEBs, such as practical guidance for the commercial building community, including cost information for owners; increased measurement and communication of results on successful design strategies and technology applications; and better benchmarking to define expectations for performance of highly energy-efficient buildings.
