Data collection is increasingly recognized as a priority in the evaluation and evolution of green buildings. Though the importance of green building design and its impact on climate change have been well documented, the actual performance of many green buildings often fails to meet expectations. There are several factors that contribute to this phenomenon, and the ability to accurately measure the energy efficiency of buildings is crucial to improving performance and standards. Performance data makes it possible to evaluate the effectiveness of different building strategies and technologies. This information is instrumental in the advancement of codes, standards, and best practices. Below, I will highlight a few initiatives that are attempting to gather and process performance data from buildings.
Data Collection Initiatives CBECS
One such effort to gather building energy information is a survey conducted by the U.S. Energy Information Administration’s (EIA) Office of Energy Consumption and Efficiency Statistics. Through the use of a national sample survey called the Commercial Buildings Energy Consumption Survey (CBECS), the EIA provides data that supports the development of energy standards and codes. The latest iteration of the survey is set to include information from approximately 8,500 commercial buildings. The two previous attempts to deliver survey results were derailed by funding issues: in 2007, a less exhaustive data gathering technique was used due to a lack of funding; more recently, poor implementation of the new technique led to faulty data that could not be used. In 2011, the survey was suspended as a result of budgetary cuts by Congress. Due to these setbacks, the latest available data dates back to 2003. Despite resuming work on a 2012 CBECS, there are still budgetary issues that might sidetrack the program.
Building Performance Partnership
Another organization seeking to collect building performance data is the U.S. Green Building Council (USGBC). The USGBC has developed the Building Performance Partnership (BPP) as a means to track and document the performance of LEED certified projects. Using tools like the EPA’s Energy Star Portfolio Manager for commercial buildings, and Wego Wise for multifamily residential buildings, the USGBC plans to begin accurately and continuously tracking the impact of LEED standards in quantifiable terms. As the project progresses, the USGBC hopes to advance energy efficiency by sharing its database of information with different stakeholders in the building industry.
Despite a New Buildings Institute study attributing a 25-30 percent improvement in efficiency for LEED certified buildings over the national average (using the 2003 CBECS information as the baseline), 25 percent of the buildings in the study fell significantly short of their projected energy saving targets. This inconsistency highlights the importance of collecting performance data. While LEED provides a framework of strategies to achieve more efficient buildings, there are a myriad of possibilities by which to meet the requirements. What the USGBC hopes to gain from the BPP is a performance database which can inform the design and development of green buildings.
Building codes and standards are essential in the progression of green buildings. One of the most important elements in establishing codes and standards is developing a minimum efficiency standard from which to work. As technology advances, so should our expectations for energy efficiency and building performance. Current building regulations are beginning to incorporate more stringent energy efficiency standards, but the collection and analysis of performance data will ensure that new benchmarks are set and achieved continuously. Beyond codes and regulations, programs like LEED and the Building Research Establishment Environmental Assessment Method (BREEAM) that seek to raise the bar in building performance can utilize data as a means to regularly evaluate, update, and validate their methods.
Initiatives like the Commercial Building Initiative (CBI) by the U. S. Department of Energy also present opportunities to apply building performance data. The CBI’s goal of advancing energy efficient technology is one that would be greatly enhanced by quantifiable information that reflects the performance of different strategies and technologies. With this information, industry leaders can ensure that the most effective technologies are being used and that those in development are meeting industry standards.
The funding issues that face CBECS present a significant challenge to the collection of building data performance. Though players like the USGBC and organizations in the private sector may begin to lead the charge in data collection, it is still important to set a baseline in the short-term for the development of codes and standards.
Another potential challenge is accurately quantifying the impact of occupant behavior on energy efficiency. Though a building may be designed to the correct specifications, occupant behavior can be difficult to predict and often leads to discrepancies between the expected energy use (derived from energy modeling during the design process) and post-occupancy energy use. Technologies likesmart meters and building management systems are making the collection of data more accurate and accessible to building occupants. Features like performance dashboards, which display real-time energy usage, are proving to have a positive impact on occupant behavior. These technologies can help us understand and quantify how different factors influence occupant behavior. These insights could eventually lead to design elements that promote more efficient behavior.
Green buildings have seen tremendous growth in the past decade, but for progress to continue, it is crucial that we have an accurate understanding of their impact on the environment. The collection of building performance data will help to ensure we use the most effective sustainable building strategies, and that building codes and standards properly address energy efficiency today and in the future.