Building commissioning (Cx) is a professional practice that facilitates the planning, design, construction, installation and testing verification, documentation, and operation of facilities and systems to conform to the Owner's Project Requirements (OPR).
Building commissioning comprises specific phases and activities for both new construction and existing buildings. Whether commissioning new construction or existing buildings, the process includes many incremental activities, usually team-based functions that result in project-specific benefits and documentation.
Cx is the ONLY profession/entity, other than the owner, that is engaged throughout the process of design, construction, delivery, and optimizing performance of facilities. CxPs require a substantial amount of knowledge, skills and experience to be able to recognize, address, and even correct issues, and building/systems performance, through the eyes of every other team member and throughout the project.
This 8–page section of the Whole Building Design Guide (WBDG) presents overall commissioning process information, guidance, challenges, and resources. The first 4 pages are focused primarily on new construction commissioning, followed by pages 5 and 6 which outline the process and guidance for commissioning existing buildings whenever it occurs from initial occupancy through the life of the facility. Pages 7 and 8 describe challenges and further resources for owners, designers, contractors, commissioning providers (CxP), and consultants.
Commissioning Benefits and Goals
The ultimate benefit of new facility and system commissioning is the documented performance of the facility and systems as it is transitioned into the long-term operations and maintenance function. Commissioning, used as a more forensic problem identification and solutions-based process, can be applied to an existing facility or system even if not initially commissioned, as described in Existing Building Commissioning.
Commissioning assists in the delivery of a project and helps to provide an efficient, safe and healthy facility; optimizes energy and water use; reduce operating costs; facilitate O&M staff orientation and training; and improve installed building systems documentation and operations. These functions can result in increased profitability in both facility and staff operations.
Commissioning benefits Owners through improved facility performance including higher quality workplace environments, and prevention of potential business losses. The cost of not commissioning is equal to the increased costs of correcting design and construction deficiencies later, plus the costs of inefficient operations. For example, in mission critical facilities, the cost of not commissioning can be measured by the cost of downtime and lack of appropriate facility use.
The primary goal of commissioning any project or system is to ensure that success for the project is clearly defined in the Owner's Project Requirements (OPR) and that the building and systems perform as intended to fulfill that mission. The commissioning process can be applied to an entire facility or to any specific system or assembly if new, upgraded or modified.
In addition to energy efficiency and overall performance drivers, another factor increasing demand for commissioning is the Owner's desire to obtain certification through building performance rating systems. These rating systems have been developed to improve the project planning, design, construction, and performance of energy and water efficiency, environmental conditions in buildings, verification, documentation, and operations practices. A building certified to these rating systems can include highly efficient gas, water, power and lighting systems, solar photovoltaics, and other energy and resource technologies. From an Owner's perspective, investment in these and other sophisticated building technologies must be accompanied by rigorous design and construction quality assurance and performance verification measurement, which are provided holistically through the commissioning process.
The principal goals of building commissioning are to:
- Include the project requirements including the commissioning process in the OPR document.
- Verify that the OPR requirements, including commissioning, are in the project design and construction documents for new projects.
- Facilitate delivery of buildings and construction projects that meet the Owner's Project Requirements.
- Prevent or eliminate problems in a cost-effective manner through proactive quality techniques.
- Verify systems are installed and working as intended and benchmark that operation.
- Provide and collect documentation and records on the design, construction, and testing to facilitate operations and maintenance of the facility.
- Facilitate training functions and system operation documentation and Cx tools for O&M staff performance and implementation of ongoing Cx.
- Lower overall first costs and life-cycle costs for the Owner.
- Maintain facility performance for the building's entire life cycle.
Commissioning definitions vary slightly based on the project phases and the function of the Cx process in the specific sequence. The commissioning process can be implemented on an entire facility or on specific systems or assemblies as required by the Owner and project.
The following definitions depict commissioning as a holistic process that spans from pre-design planning to occupancy and operations at a minimum and should also include ongoing commissioning. As stated in ASHRAE Standard 202–2018: Commissioning Process for Buildings and Systems, the following definitions are provided:
Commissioning Process (Cx) — all, including New Construction (NCCx): a quality-focused process for enhancing the delivery of a project. The process focuses on verifying and documenting that all of the commissioned systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the OPR.
Existing-Building Cx (EBCx): a quality-focused process for attaining the Current Facility Requirements (CFR) of an existing facility and its systems and assemblies being commissioned. The process focuses on planning, investigating, implementing, verifying, and documenting that the facility and/or its systems and assemblies are operated and maintained to meet the CFR, with a program to maintain the enhancements for the remaining life of the facility. See Existing Building Cx.
Retro-commissioning (RCx) is commissioning an existing building that has never been commissioned before.
Recommissioning (ReCx) occurs when a building that has already been commissioned undergoes another commissioning process. The decision to recommission may be triggered by a change in building use or Ownership, the onset of operational problems, or some other need.
Monitoring-Based Commissioning (MBCx) utilizes primarily monitored data (versus primarily manual tests and checks) originating from the Building Automation System (BAS) or other meters processed with special analysis tools, sometimes referred to as Energy Management and Information Systems (EMIS).
System-Specific Commissioning is a tailored application focused on a small subset of targeted systems in a building, such as indoor environmental quality or chiller plant efficiency.
The commissioning process ideally begins at project inception (predesign phase) and continues in phase-specific functions through facility and system operation. It is not a design or construction function, but it assists in and verifies that the results of these functions can produce a facility and systems that meets the requirements for performance. Depending upon the Owner's needs, these might include; functionality, efficiency, sustainability, environmental and health impacts, interior occupancy conditions, resilience, and others that will maximize facility and system profitability for the Owner and the occupants.
Commissioning for new construction typically involves a CxP for all phases until the building is occupied:
Phase 1 — Predesign. It is important to start the commissioning process in the pre-design phase. This early involvement by the CxP is critical for the timely and useful development of the Owner's Project Requirements (OPR), the subsequent design team Basis of Design (BOD), the Commissioning Plan, and the beginning of the Operations & Maintenance (O&M) Systems Manual. If these tasks are left until later in the process and "reverse engineered" to match the design, their usefulness as catalysts for dialog, cost and risk management, and quality tracking tools is lost.
Phase 2 — Design. During the design phase the project design and details are further developed and organized for the construction documents. These documents must be based on the design team's application of the OPR. If questions and variations to these requirements evolve during this phase, it may be necessary to update the OPR with the acceptance of the Owner or representative. The commissioning requirements are further developed during design including the selection of the systems to be commissioned and the specifications detailing the functions of commissioning and the contractor's and manufacturers responsibilities as part of the commissioning team. The commissioning plan is further developed during the design phase to reflect the design and performance requirements of the commissioned systems and the initial development of field observation, functional testing, and performance requirements, along with documentation formats for testing and reporting. During and at the conclusion of project design, the CxP reviews the construction documents to determine compliance to the OPR and inclusion of the commissioning requirements. The CxP design review is intended to verify compliance with the OPR and is not considered a PEER review. Any open issues should be responded to in writing from the designer for design completion.
Phase 4 — Hand-Off/Occupancy. At project substantial completion and after conducting operations and maintenance training by the design team (if applicable), contractors, and suppliers, the Owner assumes operational responsibilities for the facility or project. The commissioning process is not complete until the off-season testing is completed and the systems manual is completed and transferred to the Owner. At that time, a final commissioning report is developed including the final issue logs with any open items as accepted by the Owner.
NEW CONSTRUCTION/SYSTEM COMMISSIONING DOCUMENTATION
The new construction commissioning process includes multiple activities performed in a specific sequence. As defined in ASHRAE Standard 202–2018, Commissioning Process for Buildings and Systems, these functions are required to provide a complete commissioning project.
COMMISSIONING PROCESS MANAGEMENT
The facility or project Owner, or representative, defines and manages the process and reviews the documents. During project planning, the Owner also defines the extent and requirements of the commissioning process along with the basic commissioning team functions and responsibilities. Those functions are further defined in Roles and Responsibilities in the Commissioning Process.
Building and/or System Commissioning Initiation
Engaging the CxP at the beginning of the project allows the CxP to become familiar with programming documents and proceed immediately to the OPR workshop and the development of the whole building criteria that match the project needs including facility certifications such as LEED®, Green Globes, Living Building Challenge, WELL, among others, and jurisdictional requirements. The OPR should be developed during the pre-design phase. When developed first, the OPR can become a very useful tool to the Owner in selecting the correct design and construction team for the project. During the selection process of the design team, candidates' responses to the OPR when submitting their BOD provides tremendous insight into their understanding of the OPR.
Determining Project Performance Requirements
Every new project goes through pre-design and design phases that establish an Owner's needs, goals, scope, and design solutions for a proposed project. Proposed designs and constructed work can only be evaluated against objective criteria and measures that are embodied in a well-documented OPR. Project development is a learning process where building performance decisions are refined to successive levels of detail over the course of a project's life cycle. This may also include possible future programs such as solar, recycling, and new technology.
The project performance requirements are defined and assembled in the OPR document. The OPR is also the foundation document of successful Cx. It is critical in ensuring the commissioning process meets the Owner's goals. The OPR defines the cost expectations, performance goals, energy and operational benchmarks, high-level schedule dates, operational approaches, and success criteria for the project. Owner staffing plans for the facility should be clearly identified so any impact on the design of the facility systems is known. The OPR must be developed with significant Owner input and ultimate acceptance. The CxP typically assists the Owner in identifying the facility's requirements regarding such issues as energy efficiency, indoor environment, staff training, and operations and maintenance. An effective OPR incorporates input early in the project from the Owner, operations and maintenance staff, and end users of the building, and is updated throughout the project. A properly developed and updated OPR truly becomes the definition of success for a project.
Defining Cx Requirements for a Project
The commissioning process can be applied to an entire facility or project or to limited and specific equipment and assemblies. The specific commissioning application is defined in the OPR. Subsequently creating the Commissioning Plan (Cx Plan) will answer the questions and set the criteria for the commissioning process on the project.
Key project requirements and related commissioning activities include:
- Establish goals for project quality, efficiency, certifications, and functionality of commissioned systems
- Establish a commissioning scope
- Establish commissioning budgets
- Assign team members and responsibilities
- Establish commissioning plans
- Establish commissioning schedules
- Establish testing and field observation plans
- Develop commissioning specifications
- Determine scope and content of commissioning documentation and reports
- Define special testing needs
- Develop Systems Manual format and requirements
- Determine operational staff training needs
- Establish ongoing building commissioning (OCx) plans and requirements
The project requirements and the systems and assemblies selected for commissioning determine basic commissioning functions and requirements. Additionally, the Owner can require variations and options in the requirements, such as sampling or specific testing, when needed on a specific function or project.
Project Documentation, Records, and Acceptance
See the Additional Commissioning Resources page for more information.