John Heinz is a professional engineer in Seattle, Washington, and can be reached at firstname.lastname@example.org. Rick Casault is president of Casault Engineering, Seattle, Washington, and can be reached at email@example.com. They are coauthors of APPA's new book, The Building Commissioning Handbook, second edition, from which this article is excerpted. This publication was developed jointly by APPA and the Building Commissioning Association.
During the latter half of the 20th century a great deal of refinement has taken place in the building design and construction industry. Somewhat common throughout that period have been the several stages of project development--predesign, schematic design, design development, construction documents, bidding, construction, and warranty--followed by many years of operation and maintenance. Each of these phases has experienced significant process refinements, all intended to improve the efficiency and effectiveness of the process and the quality of the final product for the building owner.
One of the more recent refinements has been the introduction of building commissioning. Even though the process of building commissioning has been developing during the past 30 years, it is still in its early stages of acceptance throughout the industry. In fact, as the subject of commissioning the building is brought into the early planning or design stages for a new facility, often some of the first questions to arise are:
Each step is intended to assure the quality of the effort at hand, which is critical to the next sequential step of the program. A lapse in quality during any step can contribute to lack of proper understanding of requirements in subsequent steps, which can become cumulative and ultimately result in degradation of the final outcome, thus increasing the likelihood that the project will fall short of meeting the owner's project requirements.
For a variety of reasons commissioning is often not initiated until late in some projects, perhaps during the construction documents design phase or the construction phase. Even though this late application of the process has significant disadvantages in achieving the preferred optimum results of the commissioning process, there are still benefits to be gained. However, the potential optimum benefit will most likely have been lost.
A skilled commissioning authority can document the potential savings and economies that commissioning can bring about during each step of the process. It is a rare case when such documentation does not demonstrate that the savings achieved exceed the otherwise additional costs for corrections during or after construction and the ongoing increased energy costs that result from the loss of optimum efficiency performance of the systems.
An all-inclusive definition of "commissioning" has not been universally adopted. As one listens to early commissioning advocates it becomes apparent that definitions often reflect the specialty within a facility that is being commissioned. Electrical utilities concentrate on commissioning energy conservation measures for which they have contributed funding in order to optimize energy consumption profiles. Local fire departments concentrate on commissioning fire and life safety provisions required by related codes. Other regulatory agencies insist that provisions within their purview be proven fully operational in accordance with their specific requirements.
As these narrow definitions persist, they have had a negative effect on the proper understanding of the comprehensive
requirements for commissioning an entire facility. Whereas utilities and regulatory agencies focus on commissioning
certain systems the owner must be assured that all systems within the facility have been commissioned. Commissioning is imperative for hospitals and other healthcare facilities, and is becoming a critical requirement for high-technology laboratories and research facilities. It is also becoming an important way for classroom and office buildings to meet the specific and diverse needs of the occupants. Hence, it is essential to come up with a broad definition of total building commissioning.
The owner views the entire building as a system, one that must meet a wide range of occupancies and functional needs. Perhaps the definition from the summary report from the 1993 National Conference on Building Commissioning is
appropriate: "Commissioning is a systematic process of assuring that a building performs in accordance with the design intent and the owner's operational needs."
Another valuable characteristic of commissioning is discovery. Although no quality assurance process, including commissioning, should be expected to achieve zero defects, commissioning is a process that ensures discovery of flaws in the design or construction that will preclude facility operation in accordance with parameters set forth by the owner. Of course, discovery will inevitably occur, but it usually occurs under the most unfavorable circumstances, resulting in operating difficulties that could be critical or, in the extreme, even fatal. The least that will result from untimely discovery is inconvenience for building occupants and operations and maintenance staff. Commissioning forces discovery to take place under controlled conditions and at a time when dire consequences are least likely to result.
Further, if discovery occurs before the construction contract is accepted as complete, the consultants and contractors will bear the burden of taking corrective action and, generally, paying all related costs. When discovery occurs later the owner inherits these responsibilities and costs with little or no recourse to those responsible for the failure.
The overall goal of building commissioning is to construct a facility that operates as intended. However, it is important to recognize several specific subgoals that will be achieved as a direct result of the commissioning process.
All of the benefits that accrue to the owner lead to a higher probability that the project will be completed on schedule and within budget.
Benefits for the Design Professional
As evidenced by the increasing number of successful commissioning programs, when all parties enthusiastically accept and integrate a well-developed commissioning process into the project the process becomes a win-win situation for all involved.
When Does Commissioning Start?
There is a tendency to assume that commissioning is an activity that occurs only during or at the end of the construction period. In many cases it may happen that way, particularly in situations where commissioning had not been considered until the owner became concerned that the new facility likely would not, or will not, operate as intended. One might say, "Then it is too late." However, it is never too late. Nevertheless, there is a great deal to be gained by starting the commissioning effort much earlier in the design/construction process.
Ideally, commissioning should start during the predesign (programming) phase for the facility. A variety of factors often result in postponing hiring the commissioning authority until later, but the project team should at least agree during the predesign phase that the facility will be commissioned. If functional issues are not addressed and documented during this phase, and during the early design phases, it is very difficult to achieve the key goals of commissioning and meet the needs of the owner.
However, that is not to say that projects that have progressed past the predesign phase cannot be successfully commissioned. When commissioning is introduced during the design or construction phases, the process will not be as smooth but commissioning can still be initiated and still benefit the project. Revisions to design and construction contracts already in force will need to be negotiated in order to incorporate commissioning at these later stages.
We recommend that the services of a qualified commissioning authority be secured as early in the project as possible to help guide the process. To a great extent, the traditional members of the design and construction teams are not yet skilled in the commissioning requirements and processes.
Which Projects Should Be Commissioned?
Should every new facility be commissioned? In an ideal world the answer would be "Yes." However, the decision really becomes a consideration of what is critical to the owner in terms of health, safety, and liability risk as it relates to the primary use of the facility, and the comfort and productivity of the facility's occupants. Certainly, facilities that, by definition, provide critical services to the owner, institution, or community should be fully commissioned, including hospitals and other health care facilities, research and teaching laboratories, and any facility that handles hazardous materials or is involved with what might be considered potentially hazardous activities. The prudent owner will apply resources where they will do the most good and minimize risk for the community and the investment.
The variable involved in making decisions about which projects should be commissioned is not so much which facility should be commissioned but, rather, how much of the facility--that is, which systems should be commissioned. That becomes a process of identifying the best commissioning scope for each particular case. Should one apply total building commissioning or should it be reduced? The key to whether to pursue a reduced scope of commissioning is the assessment of the risks involved. A reduced or modified commissioning scope should be employed only where the perceived risk is low.
Which risks should be evaluated? Clearly, risks to occupants' health and safety are primary. Energy consumption efficiency should be considered for most projects. Political sensitivity, such as space being prepared for a high-profile faculty member, a project championed by the administration, or a project funded by a generous donor should receive careful consideration for commissioning. Generous donors become less generous when projects don't live up to their expectations.
Which Systems Should Be Commissioned?
Ideally, all building systems--both static and dynamic--should be commissioned. Dynamic systems are more readily recognized because they are the ones that maintain the environment, provide utility services, convey people, materials, and communications, and respond to emergent conditions. Static systems are not recognized as readily because they include the building envelope, contribute to the desired acoustic environment, minimize vibration, mitigate seismic impacts, and so forth.
Without question, all health and life safety systems should be commissioned. Building codes generally require functional performance testing of such systems to validate performance in accordance with code requirements. Municipal fire departments were probably the first to require confidence testing of life safety systems before initial occupancy; followed by annual retesting of these systems. Environmental health and safety agencies require performance testing and certification of a range of equipment and systems in high-tech research laboratories. None of this testing is optional.
Beyond the health and life safety systems, the owner should focus on those systems in previous projects whose unsatisfactory performance has plagued occupants and the operations staff. If the owner's biggest facilities operations headaches are traditionally leaking roofs and fenestration, then one emphasis of commissioning should be those systems. Roofs and window systems can be performance-tested for waterproof integrity. During the initial construction period, mockups of these construction features can be erected and tested, and accepted. The proven construction methods can then be applied to the entire facility, virtually ensuring a successful outcome.
Similarly, if indoor air quality has been a plaguing problem, applying the commissioning process to the HVAC and envelope systems will virtually ensure that the design solution, construction documents, and construction process will result in a trouble-free heating, cooling, and ventilation system. Experience indicates that, in general, seventy-five percent of the commissioning work and ninety percent of the problems discovered are associated with the HVAC systems.
During predesign is when all of the scope-of-commissioning issues should be discussed and philosophical agreement reached amongst the owner, commissioning authority, and the design professional, if available.
Can We Afford It?
The obvious concern is: How much is all of this additional effort and detail during design and construction going to cost? It is easy to jump to the conclusion that the process will inevitably increase the cost of projects. It is fair to say that at the outset there will be some net increase in the overall cost of design and construction. However, experience will prove that, when all costs of commissioning are compared with all costs of not commissioning, commissioning will not increase the owner's overall costs. Moreover, as the commissioning industry matures and design professionals and contractors become more accustomed to the building commissioning process and its benefits, it is reasonable to expect project costs to decrease, although that may be difficult to prove.
Whereas a decrease in costs may seem unrealistic,experience indicates that project management by the prime contractors is markedly enhanced due to the increased discipline for scheduling and coordinating throughout the entire construction period, with commissioning properly integrated throughout, and the increased level of quality control induced by the realities of commissioning. The net result is tighter schedule control, better consideration of submittal materials, improved installation and workmanship, and so forth, resulting in a reduction in construction deficiencies and associated delays in completing construction.
Regardless of the specific circumstances at your institution, most owners will agree that they cannot afford to not commission their new facilities.
Ed. Note: The Building Commissioning Handbook, second edition is available for $65 for APPA member institutions, $95 all others. Order at www.appa.org/applications/publications/ index.cfm.