Wednesday, 23 June 2010 20:53 Last Updated on Wednesday, 30 June 2010 19:21

First, a brief outline of 'What is building commissioning?' to set the mental image may be necessary. "Building commissioning is a systematic process of ensuring that all building systems perform interactively according to the contract documents, the design intent, and the owner's operational needs".1 Basically, commissioning is an owner's quality assurance program verifying that everything is operating as intended.

In providing advice to our clients, RD3 Sustainable Solutions prefers to have them visualize commissioning (Cx) as if they are 'drawing a straight line through a series of points where each point represents a key element of Cx in the pre-design, design, construction, and warranty phases; whereas with retro-Cx, the Cx Authority / Agent (CxA) digs back in time or recreates the current operating use of the building ('design phase point'). Ensuring the line is as straight as possible and the elements remain on target in each of the phases will result in hitting the bull's-eye and achieving optimal performance.

Many people perceive Cx as a construction phase activity ('inspections & testing'), but in an ideal situation, it should start in the pre-design and continue through the design phase to provide input in the basis of design (BOD) and design choices that affect long-term operational viability of the systems / equipment and the facility as a whole. Early involvement will best align the 'points' with the best chance at hitting the bull's-eye.

The question is, 'what are the Cx points that are best for your project' to provide you with the greatest value?

The list of possible Cx activities is lengthy but there are a number of factors that will drive which ones are best to have a CxA perform. While budget is always a factor, it is assumed that Cx has been determined to be of value and required. Following are factors that drive how to select what will be included and how in depth the Cx scope of services should be: Budget.

• Budget.
• The design.
• Construction procurement approach.
• The team: design team, owner’s delivery team, contracting team, and owner’s operating team.
• Existing building owner operating practices.
• Intended use of facility.
• Business continuity needs.
• Criticality and cost of failure / down time.
• Reliability of systems / equipment.

Budget: The goal in determining the best Cx scope of services is to get the amount of greatest value possible out of the Cx budget.

The Design: We are not referring to the design itself but the design template and if the necessary Cx elements are already included. For example, a school district may use the same design template for an elementary school for repeated developments. Has Cx been appropriately integrated into the design template to maximize the performance outcome? If the template already included previous Cx input, maybe only minor Cx review and input is necessary. If the design is a one-off, maybe full Cx design services are necessary. Another design factor is the equipment "or equivalent" clause in the specifications which will increase the need for Cx submittal reviews ensuring the alternatives proposed by the contractor meet the design intent, can be functionally tested as outlined, and will allow a similar operating performance throughout the life of the facility.

Procurement approach: The procurement approach will influence Cx scope: design-bid-build, design-build, GC/CM, etc. For example, a low bid in a design-bid-build awarded contract should have more frequent installation verification visits, more regimented pre-functional testing requirements, and very clear and coordinated specifications/CDs to ensure the installing contractors perform the work as intended. Whereas the GC/CM approach with the contractor as a member of the design team will require less intense Cx activities to achieve the same outcomes.

The Team: There are many facets to consider with the team and the level of Cx activity to include for the most appropriate team mix. Ultimately, the Cx function is to hand off a building to the owner's operating team that is functioning as intended with the knowledge and information necessary to run and maintain the systems / equipment throughout the useful lives. How strong is the design team? What level of support will they need to adequately incorporate the Cx elements into the design / construction documents? The design documents must have the necessary "teeth" to allow the CxA to hold the contracting team to an installation that will meet the design intent for the owner's eventual use. A remote, non-existent, or weak owner's team will increase the need to have the CxA to act as the 'owner's advocate' and may increase the frequency and intensity of the Cx construction phase activities. The availability of quality installing contractors in the particular market place will again influence the level and intensity of Cx activities in the construction phase. Understanding how the owner operates the facility, the approach taken for maintenance and repairs, the typical skill / wage levels of the staff, and current operating practices will change the scope of the scope activities included in the handoff, such as, systems training, level of verification of training, training documentation, O&M reviews, development of a systems manual, seasonal functional testing, re-Cx plan, preventive maintenance (PM) integration, 10 month warranty, and post occupancy testing.

Business continuity requirements and the use of the facility will impact the intensity of the Cx scope. A critical environment space, such as a data or call center, has a greater need for in depth testing of the systems prior to operations than would a general administrative office space.

The criticality and cost of failure / down time will drive Cx scope. A single point of failure (N1) system serving a critical function should be included in all of the Cx activities in each of the phases to maximize the likelihood of success. The cost of failure / down time should be integrated into the Cx scope decisions and if Cx will reduce the risk.

The reliability of systems / equipment will cause either an increase or decrease in the necessary Cx scope. An integrated system from a single manufacturer, with integrated systems manufacturing acceptance testing, may warrant a reduction in Cx testing. For example, an integrated VRV system with incorporated controls has a higher reliability of functioning properly both at the time of installation and through its operating life than a system that is made up of many devices and parts from many different manufacturers cobbled together in a construction environment. An owner may choose to statistically sample test a subset of many pieces of the same equipment installed under the same design conditions that have an acceptable reliability to determine if acceptable installation practices were achieved. Responding to the repeated types of deficiencies will allow the team to drill deeper into the corrective measures and testing, as necessary, to achieve the appropriate testing confidence interval.

In summary, it is not whether to include Commissioning; it is at what level should it be included. Cx is a quality assurance program for an owner – just having faith is a confidence but the (quality) assurance (program) is an enforcing truth to know the outcome will be as intended.

To further discuss this Article with Rob and other MEPBN Members visit the forum discussion page.

Rob de Grasse, P.E., PMP, LEED A.P., C.E.M. CxA
RD3 Sustainable Solutions
Rob is the founder and President of RD3, a facilities management consulting firm focusing of the optimization of facilities – commissioning solutions is one that this is delivered to RD3 clients.
www.RD3inc.com

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