VANCOUVER, Wash. — A new study finds that although the market generally assigns responsibility for building energy performance to the design team, operational and tenant practices have a very significant impact on building energy use.
The white paper, Sensitivity Analysis: Comparing the Impact of Design, Operation, and Tenant Behavior on Building Energy Performance, summarizes the extent to which operations and occupant behavior impact a building’s energy use compared to design characteristics, such as aspects the building envelope, HVAC systems and lighting system features. It examines how buildings use energy and what aspects of building energy performance need more attention in design, operation and policy strategies.
The New Buildings Institute (NBI) developed the study jointly with Seattle-based Ecotope, a small consulting firm that provides research, design, and analysis for projects targeting deep energy efficiency outcomes.
“The perception that energy performance is relatively set once the building is designed and constructed is not valid,” said NBI Technical Director Mark Frankel, an author of the report. “In fact, a significant percentage of building energy use is driven directly by operational and occupant habits that are completely independent of building design, and in many cases these post-design characteristics can have a larger impact on total energy use than many common variations in the design of the building itself.”
The study found that the building envelope, HVAC and lighting systems are primary areas where the design team can impact building efficiency. Best practices in envelope and lighting design can save at least 40 percent of total building energy use, while poor practices can increase energy use by about 90 percent.
When adding in the effects of HVAC system selection, best design practices can lead to about a 50 percent savings and worst practices can result in a 60 to 210 percent increase in energy use, depending on climate, according to the report.
Research showed that best practices in building operations can reduce energy use 10 to 20 percent across all climate zones but poor practices in building operations can increase energy usage 30 to 60 percent or more, although the design team may be able to limit energy loss by incorporating features such as metering and control strategies, as well as involving building operations staff in the design process, commissioning and start-up procedures.
Occupant behavior also had a significant impact on overall energy use but tenants are seldom in a position to recognize their direct effect, according to the study. Installing submetering and energy-use dashboards can help building tenants understand and reduce their energy use.
Prior to occupancy, the report stated the design team still has the largest potential impact on total building energy use, though many of the design decisions made about building features determine the degree to which operators and tenants can successfully manage their own behaviors to achieve efficient building performance.
After occupancy, operations and tenant behavior have a much greater potential to adversely impact energy use than to improve upon the original design characteristics.
The study examines the impact of various measures in different climates and suggests a range of climate-driven performance features that are not fully recognized in current design practice, or in the energy codes that regulate these features.
To view the white paper visit: http://newbuildings.org/sensitivity-analysis.