The building commissioning process bridges the gap between heightened expectations for more complex and sophisticated facilities and meeting such expectations. Many facilities managers recognize that commissioning improves facilities operations, but it is unclear what the commissioning process is and when it starts. It is not a series of activities at the end of the construction phase to make sure that building systems work right (a holdover from the early commissioning processes).
Genesis of Commissioning Process. This process evolved over 30 years from retro-commissioning to start- up commissioning (initiated in the construction phase) to commissioning in the design phase and then the predesign phase and finally a mature commissioning process, defined in ASHRAE/NIBS 0-2005. The progression from a reactive process to address poor quality to a proactive process to improve quality at each step of the capital acquisition process paralleled growth in the state of the art. A similar evolution occurs in individual institutions and construction organizations where the commissioning process is relatively new. Virtually all sustainability ratings systems require some level of commissioning.
Commissioning Process. AHRAE/NIBS 0-2005 has the most accepted definition of the commissioning process defined as “a quality-focused process” to enhance project delivery, with a focus on “verifying and documenting that the facility and all” systems “are planned, designed, installed, tested, operated, and maintained to meet the owner’s project requirements” (OPRs). This definition recognizes the importance of system interdependence for high-performance facilities (not just mechanical systems and their controls and energy use, per early commissioning). It defines OPRs (which replace and clarify “design intent”) as a document to detail functional requirements as well as use and operating expectations, such as “project goals, measurable performance criteria, cost considerations, benchmarks, success criteria, and supporting information.” OPRs detail owner needs and expectations based on interactive input from all major stakeholders, serving as a bull’s-eye target to find the right design solution and confirm that it hits the mark. The proactive quality process is state of the art, compared to fragmented and reactive past practices, but not all institutions have adopted a quality commissioning process, which can confuse the marketplace for years to come. Commissioning compels discovery under controlled circumstances, when dire (or inconvenient) results are least likely and preconstruction discovery can shift the burden of corrective action to consultants and contractors. The basis of design (BoD) document (defined in ASHRAE/NIBS 0-2005) answers owner criteria in the OPRs with a proposed solution.
Quality-Focused Process. Quality-focused commissioning tries to improve project delivery at every step, with continuous monitoring and evaluation (for example, for a new electrical engineering facility).
Goals. The overall building commissioning goal is a facility operating as intended, with several subgoals: (1) provide a safe and healthy facility (e.g., indoor air quality, laboratory operations); (2) improve energy and utility performance and efficiency (e.g., tailored system operating parameters, coordination and interface of other building systems); (3) reduce operations and maintenance (O&M) costs, increase life expectancy, and limit capital replacement frequency; (4) improve O&M staff with better training and documentation; (5) improve documentation (not just specifications and drawings) by adding OPRs and BoD documents, one-line and control logic diagrams, operating descriptions, and testing procedures and results; and (6) meet client needs through systematic verification of design and construction quality.
Scope of Commissioning. The commissioning process takes a holistic view of buildings (i.e., integrated and coordinated design, construction, and operation of building systems and assemblies). While not usually addressed by the commissioning process, many systems and assemblies have independent quality processes, so the commissioning process must verify that someone takes responsibility for test execution (and results acceptability) beyond commissioning scope.
Consolidation of traditional tests under the commissioning process is common in mechanical and electrical work (e.g., pipe leak tests). (See Figure 4.6.)
Figure 4.6. Defining Scope of Commissioning
Delete Systems, Not Tasks
|System A||System B||System C||System D||System E||System F||System G||System H||System I||System J||System K||System L|
When building systems must be commissioned, the process is specific and disciplined (e.g., owner makes commissioning expectations clear during predesign; project team creates detailed contract documents because commissioning scheduling, procedures, and activities are not well understood in construction). Aggressive acceptance milestones define a structure of verified quality at each step in facility life.
Predesign Phase. Commissioning process preparation occurs in parallel with capital project preparation. (1) OPRs add quality and performance criteria to the project plan, and designers deliver more responsive documents. The final OPR document is included in the owner- architect agreement, is a permanent part of the facility record, and is available to construction contractors. It is based on a stakeholder workshop to elicit input via open-ended questions that prompt a wide range of responses, which are ranked. The OPR document conveys raw responses, discussions on highest ranked question responses, and comments on the draft OPR document. (2) The commissioning process scope, drafted after the OPR workshop, is an early priority because the commissioning budget is part of the project budget. If the commissioning scope and budget do not align (often the case), scope must be reduced or more funds committed. To reduce commissioning scope, cut the number of assemblies or systems, not process activities; to reduce costs, cut square footage of building, not structural members (or cut systems from scope, not activities). A matrix rates each system, assembly, and feature based on key criteria (e.g., mission criticality; utility, indoor, and outdoor environmental impacts; maintenance impacts; life-safety issues; political sensitivity). (3) The commissioning process budget (for predesign, design, construction phases; final acceptance) is part of the capital project budget, but ongoing commissioning expenses in the occupancy and operations phase are not. (4) A commissioning schedule is tied to project milestones, substantial completion, final acceptance, and relevant design and construction activities. Commissioning often affects design and construction sequencing and schedules and must be included in the owner-architect agreement. (5) The preliminary commissioning plan (communications tool) describes process and scope, includes the schedule, and identifies team members and responsibilities. The plan is not a contract document but can be shared with bidders. (6) The commissioning team is specified by organizational role or title if not by name.
Design Phase. This phase has close coordination between the commissioning authority and design team, with BoD documentation, BoD and other design document reviews, and development and coordination of commissioning specifications. (1) BoD review and acceptance are a prerequisite for schematic designs and confirm that the design team understands the OPRs. (2) Design reviews (ASHRAE/NIBS 0-2005) focus on general quality, coordination among disciplines, discipline-specific reviews, and specification applicability and consistency with OPRs and BoD. Commissioning design reviews occur at strategic design process points, often milestones when owners review progress. (3) Commissioning specifications encompass general and administrative requirements (e.g., schedule of values, installation verification and testing, completion requirements, schedules, coordination, submittals, qualifications) and technical needs (e.g., commissioning sections in each specification division, such as start-up, installation verification, and testing) that contractors must understand before pricing work. Commissioning specifications are tailored to project-specific systems and assemblies and integrated with other contract provisions, with designers and commissioning authority coordinating on two levels (timely design information, specification writing skills). If owners provide standardized supplements and general requirements provisions, they do so no later than the end of design development, leaving time to coordinate any changes. (4) Documentation enhancements based on commissioning lessons include one-line drawings and sequence of operations. (5) Combining equipment specifications with performance criteria enables substitution request evaluations and provides the data needed to specify commissioning test acceptance criteria.
Construction Phase. During this phase, key tasks include scheduling and coordinating construction work, submittal reviews, installation verification and testing, creation of the systems manual and ongoing commissioning plan, and owner training verification. (1) The prebid meeting is not strictly part of the construction phase, but alerting bidders early to commissioning needs minimizes grossly underestimated commissioning work. (2) The commissioning schedule reflects a proactive quality approach, performing installation verification progressively as each system or assembly is completed, revealing issues that can be corrected as remaining work proceeds. The contractor must include commissioning process activities in construction schedule submittals, with predecessor and dependent linkages. (3) Submittal reviews and contract compliance are a designer responsibility, with a concurrent commissioning review of a sample of submittals, focusing on whether submittals meet OPR criteria. (4) Final verification and commissioning tests for installation (e.g., sample procedures, checklists, forms) are created during the construction phase. Testing requires O&M materials, so prompt submission is required after approval of product submittals. As work progresses, the contractor (a trade worker or crew chief) fills out verification forms for each unit of equipment, assembly, or work section, and the commissioning authority verifies a sample of completed forms, identifies systemic issues early to avoid recurrence, informs pay application reviews, and if needed adjusts the construction schedule. (5) Verification of training (e.g., training session monitoring; sampling of staff proficiency) is enabled by results-oriented targeted O&M training specifications. (6) The systems manual (often written by the commissioning authority, organized by trade or shop, and accessible online) includes OPRs, BoD, O&M manuals, construction record documents, training materials, system operation narratives and schematic diagrams, and commissioning process report. (7) The ongoing commissioning plan addresses the high performance during the initial commissioning process that declines after 3 years. When the commissioning process continues throughout facility life (similar to scheduled maintenance), performance degradations are monitored and corrected before they have significant impact. The ongoing plan sets up a schedule and describes continuous monitoring set up during initial commissioning, with comments on how to respond to exceptional performance and how to update and maintain the trend and alarm log features (e.g., collapsed trend log). (8) Substantial completion (when owner assumes beneficial occupancy) can affect commissioning as pressure mounts to finish the job and contract provisions are added, so completion of commissioning work (e.g., contract deficiency correction, commissioning report completion) is a prerequisite for issuing the certificate of substantial completion. The owner can grant an exception (e.g., for deferred tests, last-minute failures), but contract compliance must be the norm.
Occupancy Phase. The commissioning process continues throughout the warranty period and facility life. (1) Deferred tests, which cannot be completed during the construction phase, are commonly seasonal tests (e.g., heating water system, building envelope evaluations), occupancy-dependent tests (e.g., indoor environmental control, three-phase power load balancing), and delayed tests (e.g., replacement of items with long lead time). (2) The end-of-warranty review identifies issues for correction (e.g., premature equipment failures) while the contractor is obligated to respond; fine-tuning of set points, schedules, and control sequences; and additional needed training. (3) Ongoing commissioning uses documentation and tools created during the construction and warranty periods and incorporated into the commissioning plan schedules and the maintenance management system. Ongoing data trend logs with automated alarm conditions (e.g., declining chiller performance, rising water use, increasing machine vibration, poor temperature control, deteriorating air quality) that are left running at the end of the construction phase must be periodically reviewed, adding new logs as needed. New facilities commissioned during acquisition and maintained via ongoing commissioning might not experience deferred maintenance.
Economics of Commissioning
The costs of not commissioning can exceed 20 percent of construction costs.
Benefits. (1) Avoiding the costs of not commissioning refers to owner expenses to correct design and construction deficiencies, staff time to correct problems, needed equipment or materials, lost user time and productivity, health and safety effects, energy and utilities costs, legal fees, and significant intangible inconveniences. The first cost of the commissioning process (from predesign through construction) is usually recovered before the end of construction because higher-quality bid documents reduce bidder uncertainty, lower cost bids, and drastically reduce the number of requests for information and change orders. (2) The British Columbia Buildings Corporation study indicated that the O&M cost of not commissioning five average buildings during their first 3 years totaled 4.5 to 7.5 percent of mechanical construction costs and that lost occupant productivity totaled as much as 13.8 percent of the original mechanical contract. Even if real costs are only one-fourth of the estimates, not commissioning is costly.
Costs. Initial estimates of the first cost of the building commissioning process for large projects (more than
$10 million) use a rule of thumb (3 to 4 percent of mechanical system construction cost plus 2 to 4 percent of electrical system construction cost). Smaller projects have a slightly higher cost based on percentage of construction cost (a measure that scales well compared to dollars per square foot or dollars per energy unit saved) because of reduced economies of scale. (1) The British Columbia Buildings Corporation study cited costs for mechanical system construction commissioning of
1.5 to 6.0 percent when an independent authority, designers, and contractor share commissioning responsibility.
Acquiring Commissioning Services
Three contract documents are required to appropriately execute the commissioning process.
Owner-Architect Agreement. The owner-architect agreement is tailored (via attachments, provisions) to add architectural and engineering team commissioning- related services, including help in developing scope for and selecting a commissioning authority, communicating with the authority during design and construction, reviewing commissioning-related submittals, and resolving problems during construction (with the architect retaining final authority). Some institutions have a formal agreement model with an attachment for specifying required deliverables and documentation.
Owner-Commissioning Authority Agreement. The owner directly negotiates a services contract with the selected commissioning firm, incorporating provisions to address (1) conflicts of interest; (2) scope of commissioning services; (3) established lines of communication, tailored to level of owner involvement; and (4) authority, limited to evaluating proposed problem solutions and recommending acceptance or rejection of test results (no authority to direct the contractor to make changes). The scope of services includes commissioning duties during predesign (e.g., OPR workshops, preliminary plan, scope and budget); design (e.g., submittal reviews, specifications, on-board reviews); construction (e.g., quality assurance; witnessing, verification, and analysis of commissioning tests); and occupancy.
Selecting a Commissioning Authority
The commissioning authority is a major player in the design and construction process, so selection is key.
Criteria. Selection criteria are based on commissioning authority participation in specified activities (a function of work handled by the owner’s staff). Criteria include comprehensive commissioning process knowledge and experience (heavily weighted to facilities) and extensive experience in commissioning evaluation of mechanical and electrical equipment and systems, especially high- priority environmental control systems (which lead to discovery of incorrectly operating components beyond themselves).
Request for Qualifications (RFQ). The RFQ is advertised in local or regional trade and media, noting minimum qualifications, nature of construction project, and system types to be commissioned. The BCA database of commissioning provider firms can be searched (e.g., by state, region). Responses must meet six specific requirements: company history, commissioning expertise, local experience in last 3 years on projects of similar size and type, assigned personnel resumes and responsibilities, onsite project manager qualifications, and references. Finalists for interviews must present thorough evidence of previous project commissioning schedules, executed test procedures and commissioning specifications, and a final report.
Selection Process. A selection evaluation form for screening submittals and interviewing finalists is prepared in parallel with the RFQ, which does not ask for cost proposals (negotiated after selection).
Experience shows that the project manager is the key to success, but other involved personnel must be assessed. Claims of commissioning experience (versus experience in commissioning elements) must be thoroughly reviewed. The commissioning authority optimally is an independent third-party.
Interviews. Interviews reveal much about firm commissioning experience, different perspectives, and culture. Despite variations across institutions, team members should include the owner’s project manager, engineering and O&M division (and possibly design consultant) representatives, and a client (user) representative (to educate stakeholders and instill confidence in the selection decision).
Negotiation: Scope and Cost. The first choice commissioning firm prepares a detailed program proposal on the merits of specific commissioning. If negotiations fail, the owner can turn to the second- place firm.
A dedicated champion has led every successful implementation of the commissioning process.
Pilot Project. The cost of pilot testing the commissioning process must be justified to a capital budgeting decision maker (e,g., via in-process reporting, shared funding, senior support). The key to translating a pilot project to standard operating procedures is a well- managed and successful pilot (e.g., recording, analysis, and reporting of avoided costs and other benefits; regular progress reports to decision makers; tracking of staff O&M hours during the first year or two of occupancy; captured lessons learned).
Commissioning Master Planning. A campus with multiple facilities and ongoing capital construction can standardize the commissioning process.
Commissioning master planning starts with a workshop series (similar to OPR workshops) to create a uniform commissioning process tailored to the institution, accounts for available resources, and is focused on highest-priority features. The commissioning master plan, a how-to guide at each project phase and milestone for project managers, has master commissioning specifications and owner-architect agreement commissioning attachments and modifications. Process uniformity creates a common experience across many staff members, noting collective lessons learned.