Home  Sustainable Land Development Today April 2005
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Written by Denis M. Beaudin
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Thursday, 31 March 2005 |
What you should know about this emerging service industry.
Building Commissioning was perhaps the hottest topic at last November’s third annual International Greenbuild Expo. Most everyone in the land development industry has at least heard of the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED®) programs and understands the basics.
However, building commissioning has been a sleeper aspect, which has awakened with a roar in the past year or so. With increasing metrics on the considerable tangible and intangible values gained through commissioning services, people are clamoring to understand how commissioning works.
The History
It might be best to start with the genesis of commissioning. The traditional structure of a new construction team is vertical, rather than circular, in terms of communication and therefore lacks any real form of checks and balances. For example, in the case of heating and cooling systems:
• the owner/developer tells the architect what they want;
• the architect tells the engineer what he wants;
• the engineer tells the contractor what he wants;
• the contractor tells the mechanical subcontractor what he wants, and
• the mechanical contractor tells the testing, adjusting, balancing (TAB) sub-contractor what he wants.
Like the game when you were a child where you tried to preserve a message whispered from one person to another to no avail, the owner’s message easily transmutes down the hierarchy, leaving the TAB sub-consultant, the final line of system and installation quality control, under a different impression of the owner’s objectives. Furthermore, the TAB sub-consultant has no reporting responsibility to the owner, leaving issues to be resolved backwards through the line of command. It can take quite some time for an issue to be escalated back up through the ladder, leaving an owner/developer with an issue that has been festering in the ranks for weeks or months, and which now compromises project schedule, budget, and, ultimately, the completion of the project as desired.
So, along came commissioning. The Commissioning Authority (CA or CxA) serves as the missing link in the circular chain of communication. Typically, the owner/developer contracts directly with the Commissioning Authority, which precludes any hesitancy to “bite the hand that feeds,” which is perpetuated in the traditional project hierarchy. In our example, the Commissioning Authority documents the TAB sub-consultant’s findings, communicates these directly to the owner, and verifies conformance with the owner’s project requirements, or provides recommendations for processing resolution through the project team, as necessary.
Is There a Need?
Certainly the traditional, hierarchical approach to construction can and does work for many projects, or else it would have fallen by the wayside a long time ago. So the question arises, “When do I really need commissioning services?”
Three general categories of projects qualify for this degree of quality control:
• Projects with particular emphasis on energy-efficiency, e.g., LEED projects
• Projects with complex and/or specialty systems
• Projects with mission-critical systems, e.g., hospitals or manufacturing facilities
According to the Building Commissioning Association (BCA), while LEED projects have certainly raised the profile of commissioning, it is not the sole reason for the need or desire to have commissioning services included with a project.
For instance, while energy and processes such as HVAC serve as major targets of commissioning, technological advancements in security, telephonic, and internet (both land and wireless) systems have significantly increased the complexity of development projects. The coordination, installation, and interaction between a project’s technology systems is absolutely critical if the desired efficiencies are to be realized.
Metrics abound on the demonstrated success of commissioning in reducing a facility’s annual energy consumption and the relatively short-term payback of the required upfront investment. This is one of the reasons that commissioning is a prerequisite in both the LEED New Construction (NC) and the LEED Existing Building (EB) programs.
The more complex or unique a building’s systems are, the greater the risk of poor or inadequate systems integration. The very nature of these projects can threaten quality assurance, despite the expertise of project team personnel.
The last thing a hospital needs is an emergency system failure while a patient is on an operating table. Similarly, the impact of system malfunctions within a manufacturing setting can result in product liabilities and production shortfalls that can threaten a business’ livelihood. You might think of commissioning as a risk management tactic.
Commissioning Details
Now might be a good time for a general, working definition of commissioning. Commissioning is a quality oriented process for verifying and documenting that the performance of facilities, systems, and assemblies meets defined objectives and established criteria, i.e., verifying that the owner/developer gets what they wanted and paid for.
Commissioning can be applied to both new construction and existing buildings. Depending on the circumstances, it may be called any one of several names, including:
• Total Building Commissioning
• LEED commissioning
• Re-commissioning
• Retro-commissioning
Commissioning for new construction (including large renovations and remodels) is often referred to as “Total Building Commissioning.” Total Building Commissioning begins at the pre-design phase where the Commissioning Authority assists in documenting the owner/developer’s project requirements. Throughout the design, construction, building turnover, and post-occupancy phases, the Commissioning Authority works with project and facility staff to confirm and promote continued conformance of project development and final performance with the established project requirements.
LEED Commissioning is distinguished from Total Building Commissioning in that it focuses only on energy-using equipment such as:
• Mechanical systems
• Lighting controls
• Renewable resources systems
• Advanced technologies
Total Building Commissioning includes the remaining systems and assemblies of a building, as well. LEED
Commissioning may be applied to both new construction (LEED NC) and existing buildings (LEED EB). Commissioning new construction provides a benchmark for future recommissioning efforts to confirm proper function and performance, or to identify where function and performance may have become compromised. Re-commissioning sets up procedures for annual and seasonal performance tracking. Recommissioning can also help optimize system performance as a facility’s use profile evolves.
In contrast to Re-commissioning, Retrocommissioning is commissioning of a facility that has never been commissioned. Retro-commissioning involves three phases of work: 1). The planning phase, during which facility requirements for comfort, function, efficiency, etc. are identified, and existing systems are identified and reviewed; 2). The investigation phase, during which functional tests are performed and recommendations are formulated, and 3). The implementation phase, during which low-cost and no-cost recommendations are implemented and a budget for the remaining measures is developed.
Commissioning Qualifications
Historically, commissioning came out of engineering firms, but as the service has gained understanding and acceptance, many commissioning-only consultancies have been launched. Some of the points in LEED credits for commissioning must be provided by a third-party commissioning provider, i.e., not someone who has participated in the design.
There are many resources for locating a commissioning provider, including the U.S. Green Building Council (USGBC), the EPA’s Energy Star Program, and the BCA, to name a few. Certification of building commissioning providers is in its infancy. The BCA administered its pilot certification test last July. The University of Wisconsin at Madison also offers programs for certification based on completion of coursework, successfully passing an exam, and project experience. While standards are being established for Commissioning Authorities, one should check for some key, core competencies and experiences, including system design and installation, controls strategies, hands-on troubleshooting, operations and maintenance, and strong written and verbal communication skills.
Variables Weigh Into Costs
Commissioning costs are dependent upon a host of factors. These can include, but are not limited to:
• Type of commissioning (Total Building Commissioning, Recommissioning, etc.)
• Systems to be commissioned
• In larger-scale projects, where multiple, similar installations are present, the percentage of units to be commissioned
• Number of buildings and square footage
For a general idea of costs, a recent report entitled, “The Cost-Effectiveness of Commercial-Buildings Commissioning—A Meta-Analysis of Energy and Non-Energy Impacts in Existing Buildings and New Construction in the United States” issued by the U.S. Department of Energy, provides perhaps some of the best analysis to date, compiled “from published and unpublished data from buildings commissioning projects undertaken across the United States over the past two decades … from 224 buildings across 21 states, representing 30.4 million square feet of commissioned floor area (73 percent in existing buildings and 27 percent in new construction).”
Findings included:
• For existing buildings … median commissioning costs of $0.27/ft2, whole-building energy savings of 15 percent, and payback times of 0.7 years
• For new construction, median commissioning costs were $1.00/ft2 (0.6 percent of total construction costs), yielding a median payback time of 4.8 years (excluding quantified nonenergy impacts)
The report also quantified non-energy benefits. “Median one-time non-energy benefits were -$0.18/ft2-year for existing buildings (10 cases) and - $1.24/ft2-year for new construction (22 cases) - comparable to the entire cost of commissioning.”
This analysis also found a “six-fold greater energy savings and four-fold lower commissioning costs for existing buildings….New-construction commissioning is more strongly driven by non-energy objectives such as overall building performance, thermal comfort, and indoor air quality, whereas existing building commissioning is more strongly driven by energy savings objectives.”
The report summary concludes that commissioning could represent “a costeffective savings potential of $18 billion per year or more in commercial buildings each year across the United States”
Commissioning provides many varied and salient benefits when applied appropriately and intelligently. With a little understanding and the guidance and service of a qualified commissioning professional, you, too, can realize these benefits in your next project. SLDT
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