What is building commissioning?
Building commissioning is a systematic process of verifying that building systems meet an owner's project requirements, with an overall goal of maximizing the performance and efficiency of those systems. Depending upon the specific project scope and owner objectives, the commissioning process can be applied to a variety of building systems, including HVAC, electrical, plumbing, fire/life safety, building envelope, cogeneration, utility plants, controls, lighting, elevators, wastewater, data, communication and security.
What are the benefits of building commissioning?
Building commissioning maximizes the operational efficiency of facility systems. The commissioning process:
- Ensures all critical building systems are fully operating
- Lowers operating and maintenance costs
- Increases system energy efficiency
- Improves indoor air quality
- Reduces the risk of "sick building" syndrome
- Decreases occupant complaints and enhances productivity
- Provides better environmental control
- Reduces maintenance/troubleshooting issues
- Trains facility personnel in system operations
- Provides benchmarks to evaluate future system performance
- Reduces the life-cycle cost of the facility
What are the differences between commissioning, re-commissioning and retro-commissioning?
"Commissioning" generally refers to the commissioning of new facilities. As owners have recognized the benefits of commissioning, they are now applying the commissioning process to existing facilities.
"Re-Commissioning" refers to the commissioning of facilities which were previously commissioned. Re-testing the facility systems at a later date provides current system performance measurements, which are then compared to prior commissioning test results (now benchmarks). By comparing the test results from the initial and subsequent commissioning efforts, the Commissioning Authority (CxA) can identify problematic areas before they turn into major system malfunctions.
"Retro-Commissioning" is the application of the commissioning process to an existing facility, which has never been commissioned. The objective in retro-commissioning is to optimize the performance of existing building systems in their current environment and application. The CxA generally begins by establishing the minimum design criteria, based on the existing systems, current facility/user needs and industry benchmarks for systems performance. The CxA then tests the existing systems and compares the results to the established design criteria to identify system deficiencies. With this knowledge, the facility owner can plan, design and implement solutions to remedy system performance issues and increase energy efficiency and overall system performance.
What is a Commissioning Authority?
The CxA is the firm (or the individual within the firm) hired to provide building commissioning services. The CxA is responsible for overseeing and executing the entire commissioning process.
Ideally, the CxA is an independent third party (separate from the design and construction teams), knowledgeable in the design, construction and operation of engineered systems. A qualified CxA will provide added value to the project by applying systems expertise, experience and common sense to resolve system problems.
What qualifications should I look for in a Commissioning Authority?
The CxA should have extensive commissioning experience working with facility types and systems similar to those being commissioned. The CxA should also have experience working on projects of similar size and be able to demonstrate adequate resources (staffing) to see the project through to completion.
The CxA's firm should have both registered professional engineers and controls technicians with extensive (20+ years) building systems experience. While a number of companies have entered the commissioning arena, many provide commissioning on a "pass/fail" basis. The true value of the CXA is not only their ability to report system failures, but to also identify problems before construction (through peer review), analyze system failures to help identify the cause, work with design/construction teams in resolving these issues, and train facility personnel on system operations and maintenance activities. These services require professionals with extensive system design knowledge and field experience.
Who should hire the Commissioning Authority?
Ideally, the CxA is an independent and objective owner's representative who ensures the project is fully functional from design, installation and end user viewpoints. For this reason, we believe the CxA should be hired by (and report to) the facility owner.
Some owners have chosen instead to have the CxA work for the general contractor or project architect. While we believe this is less than ideal, this approach can be successfully implemented through the use of detailed specification sections, which outline responsibilities among the various project team members.
When should the Commissioning Authority be hired?
While commissioning services can be added at any time during a project, we suggest that the owner hire the CxA as early in the process as possible. Many owners see the value of incorporating the extensive field knowledge of the CxA into the design process. An experienced CxA has insight into which system types truly work and which systems do not. Some designs look good on paper, but may not deliver the performance expected. By having the CxA involved early in the process, the owner can tap this extensive experience by having the CxA help establish design criteria and perform design peer reviews proactively, rather than test and report reactively.
What services are included in building commissioning?
Building commissioning services are generally customized to fit specific client goals and project details. The following is a list of services available to clients through EEI and most full-service CxAs.
The commissioning services available by phase include:
- Existing facility mechanical, electrical and plumbing (MEP) evaluations
- Design criteria review/development
- Owner Program Requirement (OPR) review/development
- MEP systems master planning & budgeting
- MEP alternatives life-cycle costing
- MEP peer review
- MEP value engineering
- Quality assurance specifications
- Site/factory visits/mock-up evaluations
- Design criteria refinement
Commissioning Planning Phase
- Commissioning plan development
- System start-up checklist development
- Pre-functional test procedure development
- Functional test procedure development
Construction Services Phase
- Basic commissioning
- Shop drawing/submittal review
- Construction observation
- Commissioning schedule coordination
- Factory equipment testing
- Operations & maintenance (O&M) staff orientation
- Enhanced commissioning
- Subcontractor bid evaluations
- Request for information/change order/scope/budget review
- Construction meetings
Start-up/Functional Testing Phase
- Commissioning meetings
- Start-up/pre-functional testing - perform or observe
- Test & balance review
- Functional testing - perform or observe
- Test result analysis and recommendations
Contractor Close-Out Phase
- Punchlist review and resolution
- Record drawing review
- O&M manual review or compilation
- O&M training
- "As-built" one-line diagrams
- Final commissioning report
- Equipment warranty start dates
- Return site visits (seasonal)
- Building performance review
- Performance issue resolution
What does building commissioning cost?
The cost of building commissioning depends upon the complexity of the building systems and the scope of the services being requested. Owners typically budget MEP building commissioning at 0.5% to 1.0% of the overall construction cost. Some choose instead to budget commissioning costs at 3% to 4% of mechanical construction cost and 1.0% to 2.0% of electrical construction cost.
The value of building commissioning far outweighs its financial cost. Case studies on building commissioning projects have shown that building commissioning generally pays for itself in one to two years through increased energy efficiency (reduced utility bills) and decreased operating costs (reduced maintenance and troubleshooting costs).