This process offers benefits to the entire project team, ranging from focused planning and improved communication, to on-time successful completion and fewer callbacks.

Over the past century, and particularly over the past 25 years, many facilities’ design innovations have been implemented in order to enhance performance, protect occupant health and safety, reduce operating costs, and minimize negative impact on the environment. These innovations have led to increasingly complex - or, at least, unusual - building systems. How does one know that all of the complex features are working and/or are prepared to work when called upon after construction is complete?

Traditional design and construction industry processes have not kept pace with the evolving systems the industry is expected to deliver. Business-as-usual has been focused on equipment - its selection and sizing (design), and its installation and startup (construction) – with little or no attention being paid to how the individual pieces of equipment function together as systems.

It is no longer the case that, just because every component is installed and energized, you have a properly functioning building system. The introduction of computerized controls and networked communication between components has resulted in a critical system element, which cannot be observed through a traditional site observation or punchlist process.

Building systems commissioning is a process that has been developed to integrate into and fill this void in the traditional design and construction process. Commissioning is a systematic process of ensuring that building systems are designed, installed, integrated, and tested to perform according to the design intent and the building owner’s operational needs. It is a process that enhances the quality assurance of a building project and requires an extended project team effort to realize the full benefits.

Figure 1. Design-Phase Commissioning Activities

What is Commissioning?

Commissioning begins with the development of a project-specific Commissioning Plan. The Commissioning Plan is the roadmap for the commissioning process through pre-design, design, construction and occupancy of the facility. It lays out the roles and responsibilities for each team member during the various phases of the project, identifies the systems to be commissioned, and defines the level of rigor for each system. It establishes expectations early so there are no surprises later in the project for any team member.

The commissioning process is facilitated by a Commissioning Professional (also known as a Commissioning Authority or Commissioning Agent). However, commissioning is a team sport and a primary role of the Commissioning Professional is that of a coach. The team is comprehensive and includes the owner’s project and operations staff, the design team and construction team.

Very simply, commissioning helps the project team understand the owner’s performance goals and is a step-by-step process for successfully achieving and verifying those goals at the end of construction and prior to owner occupancy. The following are some of the fundamental elements of commissioning in project chronological order:
  • Prepare Commissioning Plan;
  • Define owner’s systems performance acceptance criteria;
  • Review design documents for compliance with acceptance criteria;
  • Prepare commissioning specification section for bidding documents;
  • Review shop drawings and equipment submittals for compliance with acceptance criteria;
  • Observe installation for future maintenance and operations accessibility issues;
  • Verify that equipment is installed and started per manufacturer’s recommendations;
  • Provide appropriate time in the construction schedule for coordinating and executing “system” level activities such as air and water testing and balancing, controls programming and checkout, and inter-system communications;
  • Verify functional performance of the systems and integrated systems to confirm final compliance with the acceptance criteria;
  • Train owner’s staff in equipment maintenance and systems operation;
  • Provide system-level operations documentation for future reference and training of owner’s staff; and
  • Develop Re-Commissioning and/or On-Going Commissioning plans for the owner’s execution throughout the life of the facility.

A Necessary Step Further

Commissioning does not replace the quality control component of a project but rather enhances the quality process on the jobsite. Quality control focuses on the static elements of the project, e.g., equipment, piping, conduit, installation coordination, etc. Commissioning goes a necessary step further to focus on how all of the static elements dynamically work together as systems. It is only through the interaction of system elements that the owner’s performance requirements can be met.

The Commissioning Professional is the eyes and ears of the future operations staff during the design and construction process, and the commissioning process brings the long-term view of the facility to the forefront of all decisions. When there are decisions to be made with respect to budget, schedule, and quality, the commissioning process helps bring as much weight to the quality issues as is given to the other two goals. Quality will not always “win,” but the owner will be able to make informed decisions with an understanding of the long-range cost of each decision.

To close the loop on the process it is essential that facilities engineering staff responsible for operating the systems are adequately prepared through training, documentation, and involvement in the commissioning process. Although the traditional project closeout activities include training of the owner’s staff, that training is typically limited to the preventive maintenance and troubleshooting of individual pieces of equipment. Commissioning takes this further by focusing on systems operation training.

Systems training provides explanations of the system performance criteria and how the designers’ systems will achieve those criteria. The goal of this training is to convey how all of the individual pieces of equipment are uniquely configured to operate as a “system.” There is heavy emphasis on schematic diagrams and automatic and manual control sequences. And, in the interest of sustained proper operation of the equipment and systems, commissioning heavily emphasizes the importance of complete, accurate, and easy-to-use systems documentation, designed with the future operations staff in mind.

Figure 2. Early-Construction-Phase Commissioning Activities

What Systems Should be Commissioned?

Any system whose performance can be defined in measurable terms can be included in the commissioning process. The following questions are helpful for determining strong candidates for commissioning on specific projects:

1.Where have problems consistently occurred on past projects?
2.What are the risks of system malfunction after occupancy/beneficial use?
3.What are the political implications of poor system performance?
4.How easily would deficiencies be found without commissioning?
5.How many parties are involved in design and construction of a single system?

For the past 15-20 years, heating, ventilating, and air conditioning (HVAC) systems have been facility owners’ first choice for commissioning. This is because HVAC systems have historically been the source of most building problems. In turn, I believe this is because HVAC systems require so many different subcontractors for successful operation (sheetmetal, piping, electrical, insulation, controls, test and balance, etc.). This number of responsible parties results in complex coordination during construction and also results in challenging troubleshooting if things don’t operate correctly upon system start-up.

Plumbing Systems Commissioning - History

So, where do plumbing systems fit in? Until recently, plumbing systems were rarely selected for the rigors of the commissioning process. That is because most traditional plumbing systems don’t score high on the previously noted five-question criteria test:

1. Where have problems consistently occurred on past projects?
Sure, there have been plumbing system failures and/or malfunctions in new buildings, but the plumbing systems are not what keep owners up at night worrying about whether or not they will function when a project is complete.

2. What are the risks of system malfunction after occupancy/beneficial use?
Probably the biggest plumbing system risk in a new building is a pipe failure or leak that could cause serious collateral damage to the building. Again, this has occurred in the past, but it is not common. Because it is such a big risk, the traditional project delivery process includes pressure testing all piping; and that, for the most part, helps to mitigate most potential problems.

3. What are the political implications of poor system performance?
This is a criterion that may qualify typical plumbing systems for commissioning in some building types. For example, in a public sports arena, what would be the result of a systemic problem with toilet operation? In a private fitness center, what would be the result of a lack of hot water or timely hot water delivery?

4. How easily would deficiencies be found without commissioning?
Other than an insidious hidden leak, most plumbing system deficiencies become evident very quickly as people find automatic faucets and flushes that don’t work; low water pressure; insufficient hot water; etc. A building owner does not need to pay a professional to search out and find these types of deficiencies.

5. How many parties are involved in design and construction of a single system?
With the exception of a few electrical connections, plumbing systems have historically been the responsibility of a single subcontractor. If there are problems with plumbing, there has not been much discussion about who is responsible for correcting them.

The above questions historically resulted in building owners choosing to commission only the following plumbing systems, if they chose to commission plumbing at all:
  • Domestic water heaters and recirculation pumps;
  • Sump pumps; and
  • Sewage ejector pumps.

  • Figure 3. Testing-and-Training Commissioning Activities

    Plumbing Systems Commissioning - Today

    All of this has changed since the turn of the millennium. Today even plumbing systems are getting to the integrated building system action and are taking on complexities previously unknown. Most of the new plumbing system designs are a result of the desire for sustainable buildings, particularly with respect to water conservation, waste water reduction, and energy/carbon footprint savings.

    The United States Green Building Council’s Leadership in Energy and Environmental Design (LEED) program requires that a building’s domestic hot water system(s) be commissioned as a prerequisite for certification. The LEED rating system has also been directly responsible for many of the innovative plumbing systems currently being designed and installed in buildings. These include, but are not limited to:
    • Rain water collection and use for flushing toilets, irrigation, and other non-potable applications;
    • Gray water collection for flushing toilets, irrigation, and other non-potable applications;
    • Solar water domestic water heating;
    • Waste energy recovery for domestic water preheat; e.g., transferring heat from chiller condensers, boiler blow-down, boiler exhaust stacks, etc.;
    • Irrigation system flow and pressure monitors;
    • Sub-metering water consumption;
    • Time-of-day scheduling of domestic water distribution; and
    • Composting toilets.
    Each of the above systems, partially because of their unique nature and partially because of their inherent controls complexity, are excellent candidates for the commissioning process.


    Commissioning offers a substantial benefit to the design and construction project by providing a framework in which the entire project team can successfully achieve their operational, schedule, and budget goals. However, the greatest value from commissioning accrues to the facility owner through focused planning, documentation, and training for the on-going operation and maintenance of the new systems.

    The project team benefits from improved communication and coordination, on-time successful completion and turnover of the building to the owner, and far fewer callbacks after project completion. The owner receives a building that works at the time of occupancy, while the designers and contractors have a satisfied customer and a more profitable project.

    The owner’s facilities team takes over a building that they understand and in which they have confidence. They are also given the tools to successfully serve their customers – the building occupants.