Building commissioning provides appreciable and calculable benefits to building developers/owners, occupants, construction and design teams, and ultimately our nation.
“Commissioning is more than “just another energy-saving measure.” It is a risk-management strategy that should be integral to any systematic approach to garnering energy savings or emissions reductions. Commissioning ensures that building owners get what they pay for when constructing or retrofitting buildings, it provides insurance for policymakers and program managers that their initiatives actually meet targets, and it detects and corrects problems that would eventually surface as far more costly maintenance or safety issues.” Evan Mills, P. (2009, July 21). A Golden Opportunity for Reducing Energy Costs and Greenhouse Gas Emissions. Retrieved from Lawrence Berkeley National Laboratory
The study referenced above, other studies as well as subjective and anecdotal input have revealed several benefits to commissioning that will be discussed in this article.
Lower Energy Costs
The Whole Building Design Guide references EPA data that shows buildings use 36% of America’s overall annual energy consumption, and 65% of the electricity demand. Energy use is also the largest operating expense for owners of commercial buildings.
Commissioning provides, at a relatively insignificant cost, assurance that buildings can deliver, if not exceed, the performance and energy savings promised by their design,1 as well as to uncover savings from “drift” of system performance in existing buildings that have already been commissioned.
Commissioning Reduces Change Orders & Other Claims Due to Gaps in Design, Scope, and Other Coordination Issues
Cooperation may not seem to be a word that fits within the context of a construction project, but Cx can help achieve it. Cooperation between the owner, the design team, and the contracting team related to the design, construction, and operation of the building.
At the highest level, building commissioning brings a holistic perspective to design, construction, and operation that integrates and enhances traditionally separate functions.1
In recent years the integration and partnering of design and contracting teams on complex building projects has increased. This has helped address the disjointedness between design intent, what is possible with current technologies, construct-ability, and best practices of the contracting teams. However, there are still challenges to achieving a completely harmonious process from initial design concept through installation and building (system) operation. However, on 74% of projects that implemented Cx, better construction team coordination was reported, and 56% of projects reported fewer change orders.5
These results are more likely when the Cx program is initiated early. For example, when the Cx program includes things like OPR development, early design phase document reviews, controls sequences, and general constructability reviews in the scope, there is significant opportunity for high value return from Cx.
This is an opportunity for growth in the industry, as Cx providers are not engaged in the design phase on the majority of their projects, despite the desire and perceived benefit of developers and owners for design phase engagement.
77% of projects reported improvements to system design, and equipment being sized correctly.5
It’s this comprehensive perspective that can minimize the impact from design changes as well, since they are identified early on, rather than as they are unfolding in the physical world, as opposed to still on paper.
Fewer Deficiencies at Substantial Completion
Once construction is underway and systems are being installed, part of the Cx process involves periodic site visits and reviews of the installed equipment.
These site visits help document progress and conditions along the timeline of the project, and identify potential deficiencies as early as possible so that they can be addressed immediately, as opposed to later in the project when they would have more significant cost and schedule implications.
Any deficiencies that are found are fully documented in a detailed manner, where responsibility is defined. Due dates, deficiency status, follow up responses and notes, and any other documentation is recorded so there is always a clear record and path to closure for every deficiency.
Managed & Documented Start-Up Procedures
A Cx plan defines startup procedures for all (or most) equipment, and checklists for contractors based on industry best practice and equipment manufacturer-defined procedures.
Typically, these startup procedures will span multiple disciplines and require an elevated level of technical and logistical coordination. As the entity responsible for bridging gaps in communication and planning between various stakeholders on a project, the Cx firm will develop a plan that defines the milestones and logical path which the work needs to follow for thorough, proper, and well documented system start-up events.
This is critical not only to maintaining a construction schedule, but oftentimes for meeting the requirements of equipment manufacturer’s warranties as well.
Smoother Building Turnover, Operations, and Post-Occupancy Benefits
A fully developed Cx plan will include processes for owner / building operator training. Operator training is often a “box to be checked” as part of a contractor’s contractual obligations, but when incorporated into a cohesive commissioning plan and with oversight by the Cx provider, the allocated hours for training can be much more effective. This is due to a more proactive approach by the Cx firm, and a focus on the specific project and the interrelated systems and disciplines.
Between 70 and 90% of the projects that implemented commissioning reported the following post-occupancy benefits.5
- Better thermal comfort
- Improved maintenance and serviceability
- Better training and education.
- Improved air quality.
- Better equipment life.
There will be less post-occupancy corrective action. Because deficiencies are being identified and corrected in real-time while contractors are still staffed on-site, there will be less, or minimal, effort required from the O&M staff to address poorly performing systems. 62% of projects reported the number call-backs was lower due to commissioning being implemented.5
Commissioning can also help produce an effective planned preventive maintenance program1.
Complete & Useful Documentation
The Cx plan and resulting documentation obtained during the project has value for the owner and operations staff. Functional performance test records can provide insight into original operating conditions, recorded setpoints, and other functional information that may be useful at future dates. Startup checklists and other reports can provide documentation that proper procedures were followed in the event of warranty disputes between an owner and an equipment manufacture, should they arise. Operations and maintenance manuals, recorded training sessions, etc. are all encompassed in the Cx plan.4
Costs & ROI of Commissioning
The LBNL study from 2018 provides the following data for building commissioning costs.5
New Construction – Costs per Square Foot
- Higher Education: $1.44
- Office: $0.82
- Healthcare – Inpatient: $0.96
- K12 Schools: $0.85
- Laboratory: $0.79
In the original 2009 LBNL study, the average payback for new construction commissioning was 4.2 years.1 While there is no updated data for payback based on the 2018 LBNL study data, the costs per square foot either stayed nearly the same or went down dramatically for some building types, so we can say that on average, the payback period should be less than 4.2 years for new building commissioning.
Existing Building Commissioning (Retro-Cx, Re-Cx)
The median savings for existing buildings is 6% of utility costs, and the 75th percentile is 10% savings.5
The median payback for existing buildings is 2.2 years, based on the 2018 LBNL study’s data.5
References
- Evan Mills, P. (2009, July 21). A Golden Opportunity for Reducing Energy Costs and Greenhouse Gas Emissions. Retrieved from Lawrence Berkeley National Laboratory
- Optimize Energy Use. (2018, March 08). Retrieved from Whole Building Design Guide
- Commercial Real Estate: An Overview of Energy Use and Energy Efficiency Opportunities. (n.d.). Retrieved from US Energy Star
- ACG Commissioning Guideline. (2005). Retrieved from AABC Commissioning Group
- Crowe, E., & Poeling, T. (2018). The Value of Commissioning: Market and Building Data Surveys.Nashville, TN: Building Commissioning Association, Lawrence Berkeley National Laboratory.
- Ganderson, J., Crowe, E., Curtin, C., Mills, E. (2018). Value of Commissioning: 2018 Market Survey.
