The Building Commissioning Process

• Introduction
• The Commissioning Process
• The Economics of Commissioning
• Acquiring Commissioning Services
• Selecting a Commissioning Authority
• Getting Started
• Conclusion
• Endnotes
• References

Introduction

We expect more of our buildings today than before. We expect greater safety and security, and we expect healthy, productive environments in which our faculty, staff, and students can live, work, and learn. We expect a reduced impact on our world from the construction, operation, use, and finally decommissioning of our facilities.

As our expectations grew over the past decades, so did the sophistication and complexity of our buildings and systems. The continuing growth of sophistication and complexity, however, has outstripped our ability to ensure that quality meets our expectations.

The building commissioning process bridges the gap between our heightened expectations, which lead to more complex and sophisticated facilities, and our need to ensure that our expectations are being met. This chapter introduces a process—the commissioning process—to bridge the gap, improve quality, and achieve our expectations for high-performance buildings. This chapter discusses the commissioning process applied to new construction and major renovations and when and how it should be applied, suggests how to acquire commissioning services, compares costs and benefits, offers steps for getting started, and provides links to resources for more information.

While the term "commissioning" may not yet be a buzzword, it seems that many facilities professionals recognize commissioning as a means of improving the operation of their facilities. In spite of this increasing recognition, confusion remains about what the commissioning process is and when it should start.

For many people, the term "commissioning" evokes a series of activities at the end of the construction phase aimed at making sure that building systems work right. This notion is a holdover from early in the evolution of the commissioning process. Unfortunately, this misconception limits the benefits realized. A brief review of the history of the commissioning process may illuminate the source of this confusion and why you should abandon it.

Genesis of the Commissioning Process

In the beginning, there was a new building that did not work right. The owner called a forensics hotshot to tell her what was wrong and how to correct it. The owner asked the contractor to correct the issues on the hotshot's list, but found completion to be slow and painful to achieve. We now call this retro-commissioning.

On the next project, the owner decided to implement commissioning during the construction phase so it would be easier to correct contract issues. Think of this as "start-up commissioning," or a rescue mission. Corrections of contract issues were completed in a more timely manner and with less conflict. But there remained design issues that were difficult to rectify.

So on the third project, the owner started commissioning in the design phase to try to reduce the number of design issues. Many design issues were corrected before contract documents were issued, so there were fewer issues during construction. However, some design issues seemed to be the result of inadequate communication of the owner's expectations to the design team.

Realizing she was on a roll, the owner started the commissioning process during the predesign phase on the next project. In the course of determining the project requirements, the owner gained a clearer understanding of her own quality expectations. Clear documentation of the owner’s project requirements helped the designers target their solutions to the owner's needs. The owner finally evolved to a mature commissioning process, which is well defined in American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)/NIBS Guideline 0-2005, The Commissioning Process.¹

This narrative of the evolution of commissioning from a reaction to poor quality to a proactive effort to improve quality at each step of the capital acquisition process describes the growth of the state of the art over a period of some 30 years. A similar evolution occurs in many individual organizations as they apply the lessons from their early efforts to apply the commissioning process to their sophisticated grasp of commissioning as their quality process for new construction.

Along the way, the sustainable future movement recognized the importance of the commissioning process. Virtually all sustainable ratings systems require some level of commissioning. This trend results from experiences with sophisticated designs that failed to deliver the promised sustainability benefits, or that failed to meet other important project requirements.

The process of commissioning is relatively new to commercial and institutional building construction. The model for building commissioning derives from commissioning industrial facilities and naval ships. The serious consequences of failure in naval and industrial systems drive the effort to systematically and proactively wring out problems before systems are brought online. The failure of traditional building start-up, combined with the high operating costs, health, safety, and environmental consequences of failure, is the impetus that is driving adoption of the commissioning process in institutional facilities.

Commissioning Process

ASHRAE/NIBS Guideline 0-2005, The Commissioning Process (available at www.ashrae.org/publications/page/1279), provides the most commonly accepted definition of the commissioning process:

A quality-focused process for enhancing the delivery of a project. The process focuses on verifying and documenting that the facility and all of its systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the owner's project requirements.

The ASHRAE/NIBS definition recognizes the importance of the interdependence of systems in delivering high-performance facilities. Early commissioning practice tended to concentrate on mechanical systems and their controls, with energy use an important target. While this is understandable given the important role that utilities played in promoting commissioning, we now understand that a successful facility requires more. Systems must interact on multiple levels to deliver safe, healthy, environmentally responsible facilities that operate at minimum cost. Power quality, which may be compromised by mechanical equipment, impacts the reliability of sensitive electronics. The heating, ventilation, and air-conditioning (HVAC) system and the building envelope work hand in hand to control the migration and condensation of moisture within building assemblies to prevent mold growth.

This definition of the commissioning process requires the definition of the relatively new term, owner’s project requirements (OPR). OPR replaces and clarifies the previously used "design intent." Guideline 0-2005 defines the OPR:

A written document that details the functional requirements of a project and the expectations of how it will be used and operated. These include project goals, measurable performance criteria, cost considerations, benchmarks, success criteria, and supporting information.

The OPR is an expression of the owner’s needs and expectations. It requires interactive input by all the major stakeholders in a capital project. While a consultant may lead the OPR workshops and draft the document, the decisions and values expressed must be those of the stakeholders. The OPR becomes the yardstick by which the owner evaluates the success of the capital project team and the operation of the facility throughout its life.

One might think of the OPR as the bull's-eye of a target. When the bull's-eye is clearly defined, we hit it more consistently. The advantage of a clearly defined bull's-eye is twofold. First, it helps the designer find the right solution. Second, it allows us to know if a solution hits the bull's-eye. That is the core of a quality process: The producer knows that he or she has hit the mark, and the receiver can verify the same. Both have an unambiguous, common measure of quality.

It is important to understand the difference between the proactive quality process that is the state of the art today, and the reactive practices of the past. In a quality process, we establish the criteria for measuring success (the OPR) before we start designing or building a facility. We then use the criteria to guide the actions of all project team members and to evaluate the degree to which they succeeded in producing results that meet or exceed the criteria.

Past practices, and the current practice of those who have not adopted the state-of-the art commissioning process, are fragmented and reactive. In some cases, the scope of commissioning  includes only limited equipment or systems within the facility.  In many instances, the commissioning team proceeds based on what they think is best for the owner, without benefit of a well-developed OPR to guide them. The fact that not everyone has adopted a quality commissioning process can result in confusion in the marketplace, which is likely to persist for some years to come.

The commissioning process aims to prevent flaws in design or construction that preclude facility operation in accordance with the OPR. To be sure, discovery does occur regardless of the application of the commissioning process. But without the commissioning process, discovery usually occurs under the most unfavorable circumstances, resulting in operating difficulties that could be critical or, in the extreme, even fatal. At the least, inconvenience for building occupants and maintenance and operations staff results. Commissioning compels discovery under controlled conditions, at a time when dire consequences are least likely to result.

Furthermore, 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 all related costs. When discovery occurs later, the owner inherits the responsibilities and costs, with little or no recourse back to those responsible for the failure.

The basis of design (BoD) document answers the owner’s criteria laid out in the OPR. The OPR and BoD are to commissioning what call-and-response are to jazz. For each OPR Criterion call, the designer responds with a narrative of the proposed design solution. ASHRAE Guideline 0-2005 defines BoD as:

A document that records the concepts, calculations, decisions, and product selections used to meet the Owner’s Project Requirements and to satisfy applicable regulatory requirements, standards, and guidelines. The document includes both narrative descriptions and lists of individual items that support the design process.

Quality-Focused Process

The quality-focused approach to the commissioning process described in this chapter seeks to improve the delivery of a project at every step. It does not limit its attention to the final results. Continuous monitoring and evaluation of the quality of the delivery delivers superior results. Conversely, when we focus solely on the last phase of facility acquisition, we miss important opportunities to improve the outcome.

For example, in a new electrical engineering facility, the design team blindly accepted the department chair’s statement that internal cooling loads would be a whopping 40 watts per square foot. Consequently, they designed a grossly oversized chilled water plant, served by a single chiller. The commissioning process flagged the oversized plant and brought stakeholders back to the table to clarify their needs. What the electrical engineering department really wanted was 40 watts per square foot in a small portion of the building to handle graduate computing rooms, but they also wanted flexibility to relocate the high-load rooms throughout the building. Redesign reduced the chiller plant to less than 20 percent of the original design, but provided oversized distribution piping within the building with frequently spaced, capped tees for future connection of fan-coil units.

The original plant would have cooled the building, even though the load was less than 10 percent of the plant capacity. The mismatch of capacity and load, however, would have shortened the life of a large, expensive chiller and consumed excess energy. An end-result-focused commissioning effort would have missed the opportunity during design to reduce the plant capacity to better match the load.

Goals

The overall goal of building commissioning is to have a facility that operates as intended. However, the commissioning process also achieves several important subgoals.

The primary subgoal is to provide a safe and healthy facility for students, faculty, staff, and the public. Commissioning minimizes functional and operational deficiencies responsible for the majority of indoor air quality problems and comfort complaints. Commissioning also minimizes liabilities inherent in laboratory building operations.

The second subgoal is to improve energy and utility performance. Commissioning is the "tune-up" that yields the most efficient performance from the installed equipment. Commissioning tailors system operating parameters to the conditions of actual use. The holistic perspective of the commissioning process also improves energy and utility performance by careful attention to the interface and coordination of the various building systems.

The third subgoal is to reduce operating costs. Equipment that operates improperly is operating inefficiently. Poor operation usually induces more frequent maintenance activity and results in shorter life expectancy for the equipment. The commissioning process reduces annual operating costs increases and limits the frequency of capital replacement costs.

The fourth subgoal is to improve the capability of the operations and maintenance (O&M) staff. Improved orientation and training coupled with more useful documentation enables the staff to sustain the high performance achieved during the initial commissioning efforts. No matter how well the equipment and systems operate at the onset, they will deteriorate without proper care, and may even be crippled by staff who do not have sufficient training or resources. Staff take ownership and pride in high-performance operation of sophisticated new systems when they are well prepared and have the tools and documents they need.

The fifth subgoal is improved documentation. Specifications and drawings do not provide all of the information needed for operation, troubleshooting, and renovation of the facility. OPR and BoD documentation, one-line diagrams, control logic diagrams, and operating descriptions help to communicate the owners’ and designers' intentions to current and future operators and designers. Fully documented testing procedures and results verify the capacity and operating parameters of the facility and systems and facilitate recommissioning as needed in the future.

The final and most important subgoal is to meet the clients' needs. When design and construction work includes a systematic verification of quality, the team will meet the OPR and achieve customer satisfaction.

Scope of Commissioning

The commissioning process embraces a holistic understanding of buildings. The successful performance of a building requires coordinated, integrated design, construction, and operation of all building systems and assemblies. Hence, the building commissioning process encompasses all building systems. The weakest link is the one excluded from a quality process.

While not normally addressed specifically by the commissioning process, many systems and assemblies have independent quality processes. From soil testing to concrete slump tests, to weld inspections and X-rays, to masonry waterproofing performance tests, to landscape soil density and water retention tests, there are well-established procedures to evaluate the performance of systems, assemblies, and materials. All of these procedures may be subsumed into the discipline of the commissioning process for ease of management. At the very least, the commissioning process should verify that someone takes responsibility for test execution and acceptability of the results for tests outside of the scope of commissioning.

Consolidation of traditional tests under the discipline of the commissioning process occurs widely in the mechanical and electrical work. The commissioning process did not invent pipe leak tests, for example. But the leak tests are prerequisites of other commissioning tests, so they must be scheduled, coordinated, and documented within the process of commissioning.

Overall, commissioning is the process that manages quality of the entire facility, from the ground up and from concept to demolition.