Building Commissioning (Cx)

Building commissioning (Cx) 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.

Building commissioning includes the following:

• Systematically evaluating all pieces of equipment to ensure that they are working according to specifications. This includes measuring temperatures and flow rates from all HVAC devices and calibrating all sensors to a known standard.
• Reviewing the sequence of operations to verify that the controls are providing the correct interaction between equipment.

In particular, building commissioning activities include:

• Engaging a commissioning authority and team
• Documentation
• Verification procedures, functional performance tests, and validation
• Training.

Building commissioning is NOT:

• Construction observation (punch list)
• Start-up
• Testing, Adjusting and Balancing (TAB)
• Final punch-out.

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

Commissioning 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.

There are several benefits of building commissioning, which include:

• Energy savings and persistence of those savings
• Improved thermal comfort with proper environmental control
• Improved indoor air quality
• Improved operation and maintenance with documentation
• Improved system function that eases building turn-over from contractor to owner.

For further information regarding commissioning, click on the following:

1. How much does Commissioning Cost?
2. The Commissioning Process
3. Building Commissioning Task