Summary of the 2009 Assessment
- Evan Mills. 2009. "Building Commissioning: A Golden Opportunity for Reducing Energy Costs and Greenhouse-gas Emissions"
- Full Report [PDF]
- Article-length summary [PDF]
- ASHRAE Journal [PDF]
- SF Chronicle summary [PDF]
- Climate Progress blog entry [online | PDF]
- Presentation fo the AABC Commissioning Group 6th Annual Conference [PDF]
- Report Charts & Supplementary Information [PPT - 22mb] [PDF - 5mb]
- Data Call
- Data collection instrument
- Engineering and economic assumptions
This report provides the world's largest database of commissioning case studies for new and existing buildings. It represents a major update and expansion of a study initially published in 2004, with roughly three-times as many projects. We gathered and analyzed data on 643 buildings, representing 99 million square feet of floor space from 26 states. The database incorporates the work of 37 commissioning providers.
Commissioning maximizes the quality and persistence of energy, cost, and emissions reductions. The process ensures that building owners get what they pay for when constructing or retrofitting buildings, provides risk-management and "insurance" for policymakers and program managers enabling their initiatives to actually meet targets, and detects and corrects problems that would eventually surface as far more costly maintenance or safety issues.
This report responds to a widely held concern that end-users do not have confidence in the nature and level of energy savings that can be achieved through the commissioning process. It addresses this issue by assembling diverse case studies and previously unpublished data, and developing performance benchmarks using standardized assumptions. The results demonstrate that commissioning is arguably the single-most cost-effective strategy for reducing energy, costs, and greenhouse-gas emissions in buildings today.
- Median commissioning costs: $0.30 and $1.16 per square foot for existing buildings and new construction, respectively (and 0.4% of total construction costs for new buildings)
- Median whole-building energy savings: 16% and 13%
- Median payback times: 1.1 and 4.2 years
- Median benefit-cost ratios: 4.5 and 1.1
- Cash-on-cash returns: 91% and 23%
- Very considerable reductions in greenhouse-gas emissions were achieved, at a negative cost of -$110 and -$25/tonne CO2-equivalent.
- High-tech buildings are particularly cost-effective, and saved large amounts of energy and emissions due to their energy-intensiveness.
- Projects employing a comprehensive approach to commissioning attained nearly twice the overall median level of savings, and five-times the savings of projects with a constrained approach.
- Non-energy benefits are extensive and often offset part or all of the commissioning cost.
- Limited multi-year post-commissioning data indicate that savings often persistent for a period of at least five years.
- Uniformly applying our median whole-building energy-savings value to the stock of U.S. non-residential buildings yields an energy-savings potential of $30 billion by the year 2030, and annual greenhouse gas emissions reductions of about 340 megatons of CO2 each year. An industry equipped to deliver these benefits would have a sales volume of $4 billion per year and support approximately 24,000 jobs.
“Commissioning America” in a decade is an ambitious goal, but achievable and consistent with this country’s aspirations to simultaneously address energy and environmental issues while creating jobs and stimulating sustainable economic activity.