December 1, 2008

Practice of commissioning sustainable buildings gains momentum

SAUL CHERNOS

correspondent

Commissioning is critical to ensure buildings operate as intended, but it’s especially true of sustainable buildings, says a Toronto commissioning specialist.

At this year’s Green Building Festival in Toronto, Adam Muggleton, a managing partner with Cobalt Engineering, offered the ASHRAE definition of commissioning — a quality-oriented process for achieving, verifying and documenting that the performance of facilities, systems, and assemblies meets the defined objectives under the criteria.

Muggleton said commissioning should be done up front, even before design work and other planning, and the building owner should be the one to hire the commissioning authority.

“The commissioning process is a quality-management tool. The object isn’t to take any responsibility away from the architect or the mechanical or electrical designers. It’s to get things out in the open, review the design and make sure the project meets the owner’s objectives. If it’s started any later, commissioning becomes about picking up pieces that have been missed.”

The commissioning authority first needs to understand the owner’s requirements and then review design documents in order to ensure consistency, Muggleton said, citing a study the Lawrence Berkeley National Laboratory conducted in 2002. Looking at 60 commercial buildings in the U.S., researchers found that, even after the occupants had moved in, 50 per cent of buildings had control problems, 40 per cent had HVAC problems, 30 per cent had malfunctioning sensors, 25 per cent had energy issues with management systems, economizers and variable-speed drivers, and 15 per cent had missing equipment.

“That’s an unacceptable outcome,” Muggleton said. “Sustainable buildings have complex automation systems that interconnect with every piece and moving part and monitor energy consumption. Owners are often spending millions of dollars.”

Commissioning is required for LEED certification, and Muggleton said this makes sense. “The more you go towards a greener, net-zero design, the more important commissioning becomes.”

Muggleton said commissioning is multidisciplinary, involving all project participants. However, it’s largely a matter of timing and communication and shouldn’t create extra work for these people.

“Commissioning is a parallel activity. You’re simply asking people to deliver a project to the performance specified.”

Proper commissioning creates an audit trail and helps hold parties accountable, yet it can make their lives simpler.

Muggleton tells of the owner of a high-end, green residence who complained things weren’t working after he moved in. “He was used to hot and cold air blowing, and we gave him radiant heat and cooling, with minimal ventilation. Because the job wasn’t commissioned, it was difficult to convince him that things were actually working properly. If the building had been commissioned from the start there would have been evidence in place, with test results, proving everything was okay.”

While commissioning should always be the first step in any project, the process does continue throughout construction, with site visits and run-throughs of the installation as it proceeds, to make sure everything works properly.

Muggleton compares the process to automotive assembly. “When a car comes off the line, a switch shouldn’t be missing. It’s a quality-control tool.”

Even post-occupancy, owners should measure and trend their energy use and have a commissioning authority at their fingertips. “If, over a period of time there’s a pick-up, they’ll know something is going on.

They can then ask the commissioning authority to investigate.”

Commissioning isn’t cheap, but it’s a fraction of the overall project budget, and the cost of not commissioning can be steep. “If your commissioning authority comes on board early enough and makes a difference, you’ll catch things early and have reduced change-orders, requests for information, and deficiencies,” Muggleton said.

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