Commercial Buildings: Commissioning

Building commissioning is a systematic process of ensuring that a building performs in accordance with the design intent, contract documents, and the owner's operational needs. Due to the sophistication of building designs and the complexity of building systems constructed today, commissioning is necessary, but not automatically included as part of the typical design and construction process. Commissioning is critical for ensuring that the design developed through the whole-building design process is successfully constructed and operated.

These activities are individual steps in the systematic process of commissioning, but by themselves these activities cannot meet the goals of building commissioning.

Commissioning heating, ventilating, and air-conditioning (HVAC) systems is even more important in energy-efficient buildings because equipment is less likely to be oversized and must therefore run as intended to maintain comfort. Also, HVAC equipment in better performing buildings may require advanced control strategies. Commissioning goes beyond the traditional HVAC elements. More and more buildings rely on parts of the envelope to ensure comfort.

Commissioning includes evaluating the building elements to ensure that shade management devices are in place, glazing was installed as specified, air-leakage standards have been met—these are the static elements of the building. Commissioning can also evaluate other claims about the construction materials such as VOC emission content and durability. It is important that the products that were specified for the building meet the manufacturer's claims (and are appropriate for the project).

Continuous commissioning ensures that the building operates as efficiently as possible while meeting the occupants' comfort and functional needs throughout the life of the building. Continuous commissioning differs from building operation and maintenance.

However, building commissioning goes beyond these plans and manuals with a more systematic and integrated process.

The Building Commissioning Association's goal is to achieve high professional standards, while allowing for the diverse and creative approaches to building commissioning that benefit the profession and its clients.

Commissioning Costs

Building owners are finding that the energy, water, productivity, and operational savings resulting from commissioning offset the cost of implementing a building commissioning process. Recent studies indicate that on average the operating costs of a commissioned building range from 8-20 percent below that of a noncommissioned building. The onetime investment in commissioning at the beginning of a project may result in reduced operating costs that will last the life of the building.

The cost of commissioning is dependent upon many factors including a building's size and complexity, and whether the project consists of new construction or building renovation. In general, the cost of commissioning a new building ranges from 0.5 to 1.5 percent of the total construction cost, as shown in the table. For an existing building, never before commissioned, the cost of retrocommissioning can range from 3 to 5 percent of the total operating cost.

Source: Mills E et al. 2004. The cost-effectiveness of commercial buildings commissioning. Lawrence Berkeley National Laboratory. LBNL report #56637 (PDF 3.5 MB). Download Adobe Reader.

Commissioning Process

Commissioning ideally occurs through all phases of a building project. Designate a commissioning agent as early as possible in the project time line, ideally during the pre-design phase. While it is beneficial to have a third party commissioning authority for more comprehensive design and construction review, it is acceptable for a project to use a qualified member of the design team as the commissioning agent (CA). The commissioning provider serves as an objective advocate of the owner, directs the commissioning process, and presents final recommendations to the owner regarding the performance of commissioned building systems. The commissioning provider introduces standards and strategies early in the design process and then ensures implementation of selected measures by clearly stating target requirements in construction documents. The CA then verifies that the minimum targets have been met after construction completion. In addition, the CA should provide guidance on how to operate the building at peak efficiency.

The following checklist is a guide to commissioning activities and documentation:

Owner's requirements—List and describe the owner's requirements and basis of design intent with performance criteria.

Commissioning plan—Create the commissioning plan as early in the design phase as possible including the management strategy and list of all features and systems to be commissioned.

Bid documents—Integrate commissioning requirements in the construction bid and contract documents. Designate the Construction Specifications Institute (CSI) Construction Specification Section 01810 in Division 1 for general commissioning requirements. Use the unassigned Sections 01811 through 01819 to address requirements specific to individual systems. Notify the mechanical and electrical subcontractors of Division 15 and 16 commissioning requirements in Sections 15995 and 16995.

Functional performance test procedures and checklists—Develop functional performance test procedures or performance criteria verification checklists for each of the elements identified in the commissioning plan.

Commissioning report—Complete a commissioning report for each identified component, equipment, system, or feature including the results of installation observation, start-up and checkout, operation sampling, functional performance testing, and performance criteria verification.

Training—Assemble written verification that training was conducted for appropriate personnel on all commissioned features and systems.

Operation and maintenance manuals—Review operation and maintenance manuals for completeness including instructions for installation, maintenance, replacement, and start-up; replacement sources; parts list; special tools; performance data; and warranty details.

Recommissioning management manual—Develop an indexed recommissioning management manual with components such as guidelines for establishing and tracking benchmarks for whole building energy use and equipment efficiencies; recommendations for recalibration frequency of sensors; list of all user adjustable set-points and reset schedules; and list of diagnostic tools.

Two organizations that provide information and standards on building commissioning are the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) and The International Energy Agency (IEA). The ASHRAE Bookstore contains useful publications about commissioning, including ASHRAE Guideline 0-2005, The Commissioning Process.

IEA acts as energy policy advisor to 26 member countries in their effort to ensure reliable, affordable and clean energy. The IEA provides support for over 40 international co-operation and collaboration agreements in energy technology R&D, deployment, and information dissemination. One of these agreements is the Implementing Agreement on Energy Conservation in Buildings and Community Systems (ECBCS), which focuses its work on ways to improve energy efficiency in buildings. The ECBCS coordinates research projects, or annexes, on various aspects of building commissioning. One of the ongoing projects is Annex 47. Cost-Effective Commissioning for Low-Energy Buildings.

Systems Integration Issues

The commissioning process is the mechanism to ensure that the interface between the trades is working properly. It affects all dynamically operated components, equipment, systems, and features as well as the environmental performance aspects of selected static materials and systems.

Additional commissioning supplements fundamental commissioning and focuses on review of the building design and construction documents to identify areas for improvement as well as recommissioning of building systems after occupancy.

Be sure to address the commissioning process at any pre-bid or pre-construction conferences as well as design and construction meetings.

The construction contractor should understand that a third-party person will be evaluating their work for compliance with the specifications. They should be prepared to assist and provide appropriate documentation.

Learn More:
The Portland Energy Conversation, Inc. (PECI) Resource Library provides access to commissioning and O&M resources, case studies, and guidelines. In addition, PECI staff papers and links to other commissioning-related organizations are provided.

U.S. Department of Energy - Energy Efficiency and Renewable Energy

Building Technologies Program – Commercial Buildings

Commissioning

Commissioning Costs

Commissioning Process

Systems Integration Issues