Building Commissioning Allows Testing for Sustainability

by Tracy Ostroff

Summary: When a building works properly, it uses less energy and provides a better environment for occupants. Building commissioning offers a way for architects to ensure that the sustainable systems they have programmed are working as designed. The goal of commissioning is to provide a more efficient building with fewer problems for the building owner and the best indoor environment for the occupants. Building commissioning should first be considered by the owner and the architectural/engineering team in the schematic design phase.

What is building commissioning?
Building commissioning is a systematic and documented process of ensuring that the owner's operational needs are met, building systems perform efficiently, and building operators are properly trained, say Washington state officials.

Washington’s commissioning program helps carry out the mission of an executive order that requires government agencies to look at the U.S. Green Building Council LEED®-Silver requirements for all new construction projects, says Roger Wigfield, an energy systems manager and manager of Washington State’s building commissioning program. Commissioning is a LEED point toward certification.

What are the costs and benefits?
Wigfield says Washington State officials worked with the Northwest Energy Efficiency Alliance to research how commissioning affected energy savings. “We found that typically you could get 14 or 15 cents/square foot in energy savings and then you could also get about 19 cents/square foot in other benefits to the building owner,” he says. That translates into “better equipment where you didn’t have as many callbacks, fewer change orders, and improved air quality for the occupants. If you put both of them together, you could come up with about a quarter to half the costs of commissioning covered out of just the energy savings and other benefits to the owner.”

Building commissioning for a new building ranges from the low side of about 75 cents/square foot to a high of $2.50/square foot, depending on the types of systems being commissioned and the complexity of the building. For complex buildings, such as prisons with door actuators and a lot of electronic controls, the cost tends to be higher. For a school with a VAV system, the costs would be lower, probably closer to the $1.25/square foot, Wigfield estimates.

To control costs, Wigfield says the owner can decide to test only some systems, such as ones that have been problematic in prior projects, or to test a sampling of building systems. From there, the team can decide if the further testing needs to be carried out.

“The benefits to the private sector are the same as to the public sector except the public sector is a little more willing to look at the longer payback items,” Wigfield says.

What architects should know
Ideally, owners should have let the architects know upfront that they will have the building commissioned. “Typically, it’s the architect who controls the budget, so when you have a commissioning firm involved, you need to allow a little bit of extra time for your engineering team for a couple of extra reviews. You have to make sure the contractor understands the owner has a building commissioning program and is going to have the systems tested so that the contractor can build in any costs,” Wigfield says. The keys are communicating the intent early on, so that “nobody is complaining at the end that they didn’t have the proper budget or didn’t know that this was going to happen.”

Wigfield says he typically works with an independent commissioning agent separate from the architects or engineer. “Typically the architecture firms don’t have the engineering or technical staff to do the actual commissioning. It could be something they want to add sometime, but the firms that I’m familiar with right now don’t have that capability.”

Wigfield advises: “Commissioning isn’t the thing that happens during the last two weeks during functional testing. It’s a process that starts in the schematic design or even earlier and goes clear through construction and the warrantee period, so if there are issues they can be identified and straightened out.”