Designers devote their time, energy and
imaginations to creating
pleasant and inviting interior spaces for clients. Unfortunately, when occupants are distracted by uncomfortable temperatures or ill-effects from poor ventilation, they rarely delight in their surroundings. Commissioning a Leadership in Energy and Environmental Design for Commercial Interiors (LEED-CI) project helps ensure that the systems are working as intended. Not only does commissioning help your clients achieve the maximum benefit from the sub-systems they've selected, it also helps employees stay focused on their work and the positive attributes of the space. The LEED rating system recognizes the importance of commissioning with a prerequisite and offers the ability for project teams to gain five additional points for implementing a more comprehensive commissioning process.
Commissioning was one of the few positive outcomes of sick building syndrome. Because of the expense, engineering firms had relinquished the responsibility for verifying the post-construction accuracy of systems' operations, which left a significant void between anticipated and actual performance. When occupant health declined, people took notice.
Commissioning authorities bridge the gap between design and operations by reviewing how the systems operate independently, and how they interact together. These specialists employ a systematic approach to confirm that the systems were installed and function to design specifications. In the best-case scenarios, they also ensure that staff know how to operate the systems correctly.
commissioning levels of leed
Within the LEED framework, commissioning generally refers to the energy-using systems: Heating, Ventilating and Air Conditioning (HVAC), lighting controls, domestic hot water and renewable energy systems when incorporated. Outside of LEED, commissioning may include fire and life safety systems, the complete electrical system, plumbing and the building envelope. In a LEED-CI project, the systems reviewed usually refer to the sub-systems that affect the tenant's domain, such as the fan coils and the variable air volume terminal units that deliver the building air and regulate it for the space.
Fundamental commissioning of building energy systems is an Energy and Atmosphere Prerequisite in LEED-CI. To meet the requirement, every project must have a commissioning authority involved. Commissioning authorities attend a meeting during design development to coordinate the commissioning process and may assist with the creation of the Owner's Project Requirements (OPR) and Basis of Design (BOD) documents. Commissioners review the OPR and BOD documentation for completeness and clarity. They then develop commissioning specifications for incorporation into the construction documents, and develop and implement their commissioning plan.
The "field work" near the end of construction
includes verifying equipment installation in accordance with the manufacturer's instructions and documenting performance of the systems to meet the design intent. A summary commissioning report is developed and submitted to the owners at each project's completion.
Enhanced commissioning is a more holistic approach that offers project teams five points under LEED-CI. In addition to all the elements required for fundamental commissioning, authorities perform a commissioning design review of the OPR, BOD and design documents before halfway in the construction documents phase. During construction, commissioners review the contractor submittals for compliance with the OPR and BOD, and distribute review comments to the design teams and owners.
During enhanced commissioning, authorities conduct an operations and maintenance review, and develop a systems manual informing future staff on how to efficiently operate, calibrate and maintain the systems. Commissioners verify that adequate training is in place, so staff won't need to consult a manual or construction drawing to find, for example, a valve when a water pipe breaks. In fact, if the authorities attend these training meetings,
they can assure that the contractor is actually there—not just a product representative who has no idea of where the valves and circuits are located.
Commissioners also return to each project within 10 months of installation for another systems review during the warranty period. Depending on the time of year a tenant improvement is completed, a six-month timeframe may provide the opportunity to see how the systems operate in opposite seasons. If problems exist—and invariably something goes awry—many can be fixed on the spot. For others that require more attention, commissioners must write a plan to direct staff how to resolve the issues.
LEED requires each commissioning authority to have documented commissioning experience in at least two building projects. Under the fundamental commissioning process, project team personnel can serve as commissioners. But enhanced commissioning is more stringent, requiring that commissioning authorities not be involved in the design and construction work, and not be employees of the design or construction firms. Commissioners may be contracted through the design firm (but not the construction firm), and are allowed to be qualified employees or consultants of the owner. These enhanced requirements make sense, as the purpose of a commissioning
authority is to offer an independent third-party review. As owner advocates, they can do the best job if they bring a non-biased opinion to the process.
Commissioning isn't just a LEED prerequisite; it's also financially sound advice for your client. In the October 2003 study titled "The Costs and Financial Benefits of Green Buildings—A Report to California's Sustainable Building Task Force," by Gregory H. Kats, he calculated that the premium for LEED buildings ranged between $3 to $5 per square foot. Decreased operating costs provide the clearest return on investment, and the study found that commissioning LEED buildings combined with the energy and water savings generated $1.16 per square foot of annual savings, which equates to a 20-year present value of $14.77 per square foot, based on a 5 percent discount rate. The savings make a strong case for commissioning.
finding the right commissioning authority
So how do you know what to look for in a good commissioning authority? The first qualification should be experience in the project's specific industry sector—namely, tenant improvements. If commissioners have a lot of experience in new construction but none in TIs, they might miss critical elements related to achieving your client's goals. For example, they might assume that because the building's HVAC system works, it's not worth checking. But the overall building system might not interface well with the sub-systems that your client wants to install or meet client objectives for outside air ventilation.
The next criterion in a good commissioning authority is a team attitude. You want someone who will work together with you to get the best results. This person should tell team members about issues they uncover and give them the opportunity to fix them first. Finally, and most importantly, find someone who brings an unwavering
attitude that they are working for the owners' benefit, regardless of who writes their check. You need someone who makes judgments based on quality not price, as the systems should serve the owners' and occupants' needs for years to come.
Designers and commissioners share the same goal: client and occupant satisfaction. With the right commissioning authority, you can be sure that the systems perform as anticipated; that in turn will produce real long-term value for your client and let the quality of your design shine through.
Doug Crombie, PE, is a senior technical consultant at Green Building Services Inc., one of the leading comprehensive sustainability consulting firms in the nation. Doug has extensive experience in analyzing and
optimizing building performance and specializes in commissioning for clients throughout the United States. Doug can be reached at (866) 743-4277 or email@example.com.