“Commissioning is one of the most potent and yet least understood strategies for managing energy use, costs, and associated greenhouse gas emissions in the buildings sector.”– Evan Mills, Ph.D.
Building owners and managers often ask what are the costs and benefits of building commissioning. A report completed by Evan Mills, Ph.D. of the Lawrence Berkley National Laboratory and released in July 2009, addresses this question and others regarding the future of building commissioning. The report, Building Commissioning: A Golden Opportunity for Reducing Energy Costs and Greenhouse Gas Emissions, compiles information from the world’s largest database of commissioning case studies for new and existing buildings, analyzing data on 643 buildings representing 99 million square feet of floor space from 26 states. The database incorporates the work of 37 commissioning providers.
Some of the observations from the analysis note that 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 policy makers 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.
The 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. Dr. Mills’ report demonstrates that commissioning is arguably the single most cost-effective strategy for reducing energy, costs and greenhouse-gas emissions in buildings today. Key findings of the report include:
- Median commissioning costs of $0.30 per square foot for existing buildings and $1.16 per square foot for new construction
- Median whole-building energy savings of 16% (existing) and 13% (new) with median payback times of 1.1 years (existing) and 4.2 years (new)
- Very considerable reductions in greenhouse-gas emissions were achieved at a negative cost of -$110 and -$25/tonne CO2-equivalent (existing and new).
The report also notes that performing commissioning services for high-tech, energy-intensive buildings such as hospitals, data centers and laboratories are particularly cost-effective and save large amounts of energy and emissions. Projects that employ 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. Also, non-energy benefits are extensive and often offset part or all of the commissioning cost.