When people think of the energy a building uses, they usually think about lights, heating or air conditioning. These items do consume energy, but other building attributes also affect the amount of energy used by a building. The building envelope, walls, roof and windows also contribute to building energy use. The quality of construction has a large impact on the building’s overall energy consumption and is important for two reasons. First, if a building uses less energy, the owner pays a smaller utility bill, reducing ongoing operational costs. Second, decreased energy use equates to reduced CO2 emissions and a lessened environmental impact.
When people think of the energy a building uses, they usually think about lights, heating or air conditioning. These items do consume energy, but other building attributes also affect the amount of energy used by a building. The building envelope, walls, roof and windows also contribute to building energy use. The quality of construction has a large impact on the building’s overall energy consumption and is important for two reasons. First, if a building uses less energy, the owner pays a smaller utility bill, reducing ongoing operational costs. Second, decreased energy use equates to reduced CO2 emissions and a lessened environmental impact.
The Commissioning Process
The building commissioning process helps to ensure that building energy systems perform efficiently and that the building will operate as intended. The LEED prerequisite associated with commissioning, Energy and Atmosphere Prerequisite 1 (EAp1): Fundamental Commissioning, addresses all building equipment that will consume energy or water; or produce energy, in the case of buildings with on-site renewable energy systems. This prerequisite is a systematic quality assurance and quality control program ensuring various parameters are met, including the following:
- The design of the building systems is consistent with the Owner’s Project Requirements (OPR).
- The equipment that has been designed for the project is purchased.
- The purchased equipment is delivered to the site.
- The delivered equipment is installed correctly and, once installed, is started up according to the manufacturer’s recommendations.
The Commissioning Authority
The Commissioning Authority (CxA) for LEED projects must be a person or group of people who can demonstrate that they have experience in commissioning building systems. They are independent from the design or construction teams. They are impartial and review the design as well as the quality of construction to make sure the owner is getting what they paid for and that the systems are installed and will operate as intended at the construction’s completion. The CxA’s role on a project is not to police the contractors; rather it is to help the team deliver a building that operates within the guidelines of the OPR and the manufacturer’s recommendations.
The LEED commissioning process helps to ensure that mistakes don’t happen. The prerequisite requires the CxA to develop a commissioning plan. This plan details how the inspection, testing and verification of equipment and systems will take place.
The fundamental commissioning process begins during design. The design team will work with the CxA to demonstrate how selected equipment will fulfill the owner’s requirements and to determine if the equipment is sized correctly and will operate efficiently. The commissioning process continues through construction and at the conclusion of the commissioning process, the CxA must provide a summary report of the results, which must be delivered directly to the owner.
Enhanced Commissioning
LEED Energy and Atmosphere Credit 3 (EAc3): Enhanced Commissioning awards points to a team to enhance or go beyond the fundamental commissioning activities. The credit allows for teams to earn up to three points (depending on the particular LEED rating system used) by including additional commissioning activities above and beyond the requirements of Fundamental Commissioning. The Enhanced Commissioning process starts before construction begins and is not finalized until 10 months after construction is complete and the owner has occupied the building. The Enhanced Commissioning process should begin as early in the design process as possible, and the LEED rating system requires the process to begin no later than the halfway point of design completion. At this point, the CxA will perform a review of the design to date and review drawings and specifications to make sure the design will function as intended. The review also identifies areas of constructability. The CxA will make recommendations to the design team as to how the systems may be improved from both an energy efficiency standpoint as well as an overall impact to sustainability.
Performing a commissioning review of the design at the 50 percent mark is required so that changes or suggestions can be incorporated with the least amount of impact in terms of time and money. As the design proceeds, the CxA makes sure that commissioning requirements have been included in the specifications and that clear direction is provided to the contractor. In addition to on-site construction inspections, the CxA reviews all applicable submittals from the contractor. This review provides additional oversight to to ensure the equipment included in the design will be purchased, and that the CxA is retaining the information necessary to compile an operations manual on behalf of the owner.
This manual compiles all of the manufacturer’s information with recommendations on how to operate the building as an integrated system instead of as single pieces of equipment. In Enhanced Commissioning, the activities performed by the CxA during the project’s construction phase are identical to those required for Fundamental Commissioning. However, to meet the requirements of Enhanced Commissioning, the CxA must ensure training is provided to the building operator at the construction’s completion and that the training is appropriate for the building’s systems. The CxA will also return to the building within 10 months of building completion to perform a final inspection process with the owner’s staff to make sure that the equipment and systems are functioning as they were at the completion of the fundamental commissioning activities and system start-up.
Benefits of Commissioning
This may seem like a lot of effort for three LEED points, but point accumulation of points should not be the only goal. The ultimate reward is owners know the systems within their building are operating correctly, their staff has the training to operate the building systems in the most efficient manner possible, and any issues with the equipment are identified before the warranty period ends. Commissioning has multiple benefits, including correcting problems before they become bigger problems, achieving LEED points, making sure operations staff is well-trained, knowing the building works the way it was intended and reducing ongoing maintenance costs. When viewed in this light, most building owners agree that they really can’t afford not to commission their buildings.
Thomas Taylor, a 29-year veteran of the construction industry and noted expert on sustainability, is the general manager of St. Louis-based Vertegy. His recent book, “Guide to LEED 2009: Estimating and Preconstruction Strategies,” provides step-by-step information about the LEED 2009 for New Construction process. To learn more about Vertegy or Taylor’s new book, visit www.vertegyconsultants.com for more information.