Building Commissioning for New Construction

Building commissioning helps ensure that building systems operate efficiently, meet the needs of the end user, function as designed, and maintain occupant comfort. The initial costs of commissioning are recovered many times over through operating savings, improved staff performance, and avoidance of costly construction problems.

Why Commission a Building?

The reason building owners have their buildings commissioned is because it is cost-effective. Poorly performing buildings inherently have higher costs. Building owners want buildings that work. They want comfortable, healthy environments for their tenants and employees. They recognize that a high performance building is a key element for business success. It gives them a competitive advantage.

It is important to realize that building commissioning is not common practice. Typically, new buildings do not perform as intended. This is due, in part, to owners and developers wanting to keep first costs down. As buildings and systems have become more complex, the need for commissioning is even more important.

What is Building Commissioning?

Building commissioning is the systematic process of ensuring and documenting that all building systems perform interactively according to the design intent and the owner’s operational needs. This process begins in the design phase and lasts at least one year after project close-out, and includes training of operating staff.

The key elements in building commissioning include:

• Thorough documentation of system design intent, operating sequences, and test procedures.
• Verification of system performance based on extensive functional testing and measurement.
• Training of building operations staff on system operation and maintenance procedures.
• Ongoing monitoring of system performance.

Who Commissions a Building?

Who actually performs commissioning depends on the owner and the project. Typically, the building owner hires an independent third party to perform commissioning. This individual is often referred to as the commissioning agent (CA).

Those involved in the building commissioning field generally believe the CA should work for the owner and represent the owner’s interest. However, there are numerous options. The commissioning agent can work under contract to the construction manager. This works well when the construction manager is independent of the contractor’s team. There is interest among architect and engineering firms to include commissioning as part of their services to help ensure they deliver quality buildings to their clients.

What are the Steps in Commissioning?

The extent of the commissioning process can vary as well as the roles of those involved in the project. Ideally the CA is hired during the pre-design phase and is involved through the post-acceptance phase of the construction process. The roles of the CA in each phase of the design and construction process are described below.

1. Pre-design
   
   The CA, working with the owner, establishes the parameters and expectations for the commissioning process. The CA may have a limited input and review role in this phase.

2. Design Phase
   
   The CA will outline the scope of design requirements and design intent, describe the systems to be installed, outline the documentation requirements for each party involved in the commissioning process, define subsequent commissioning procedures, and document the process.

3. Construction Phase
   
   The CA completes the commissioning plan at the beginning of the construction phase. The CA obtains project schedules and gathers and reviews the contractor submittals and operation and maintenance manuals. The CA writes detailed functional performance test plans for each system and piece of equipment involved in the commissioning process.

   The CA makes site visits to observe construction, noting details that might affect equipment and system performance or operation. He or she coordinates with the various contractors to perform the pre-functional performance tests. The CA oversees all start-up tests and ensures that pre-functional performance tests and checklists are completed and all deficiencies resolved.

4. Acceptance Phase
   
   Using the functional performance test plans, the CA observes and verifies the proper operation of equipment, systems, and controls per contract documents. He or she verifies that corrective measures are taken, and ensures the presence of complete operation and maintenance manuals. The actual performance testing is usually carried out by the various contractors. The CA oversees this process and may be actively involved. Shortly after the functional performance tests are complete, the CA finishes a commissioning final report, including all documentation, and submits it to the owner.

   Training for the building operation staff generally occurs near the end of the acceptance phase or shortly after the building is occupied. The training should be done by the installing contractors, designers, and manufacturers’ representatives and may include the CA. The CA should be involved in establishing the training needs of the building operation and maintenance staff and ensuring those needs are met.

5. Post-Acceptance Phase
   
   Building operation and maintenance staff ensure the proper functioning of the facility’s systems, adapt the system to changing occupancy and use, maintain a history of the facility, and document all changes. The CA can be involved in establishing the documentation methods for this phase and in reviewing performance and recommending improvements.

What about Cost?

The price of building commissioning varies depending on the size of the project, complexity of building systems, and the systems to be commissioned. The following ranges provide rough rules of thumb:

Total building commissioning: Less than 1% of total construction cost

Equipment commissioning: 2% to 5% of equipment cost

Owners often say they cannot afford to pay for building commissioning. It is important to recognize the potential costs of not commissioning. These costs include schedule overruns, change orders, litigation costs, high vacancy levels, uncomfortable occupants, excessively long shakedown periods, costly post-occupancy corrections, and inability to perform adequate operation and maintenance. These costs can far exceed the price paid for commissioning. Commissioning reduces the risk of incurring these costs. Also, experience has shown that a building that is not commissioned will cost 8% to 20% more to operate than a commissioned building.

——

Note: This article was first published in February 1998.