For all the promise of rotation, Selkowitz's dream carousel almost died when Overaa's low bid of $10.3 million for the entire FLEXLAB came in $1.7 million over the $8.6-million budget estimate.

The turntable does not rotate 360˚ because the other sheds are to the east. Even so, the cost of 270˚ rotation is $1 million. That was "a real eye-opener" for the lab's scientists, says Richard Stanton, FLEXLAB's project director for the Berkeley lab's facilities group. "It is expensive to incorporate rotation into a permanent structure, meet seismic and safety codes, and deal with electrical feeds," he says.

After two months of value-engineering, including eliminating a static test bed and other elements, Overaa's price came down by $948,620 to an acceptable $9.4 million. The rotating test bed had survived the cuts. The lab issued a notice to proceed in June 2012.

Overaa's current contract, including add-ons, is at $9.8 million. The overall project is within budget, thanks to a contingency fund, says Ross Schaefer, FLEXLAB's project manager for the Berkeley lab.

The diminutive size and shed-like looks belie FLEXLAB's complexity. "We've had to overcome many technical challenges," says Schaefer.

The test cells are really science labs disguised as office space. "You couldn't use rules-of-thumb on this job because it was so different," says Tyler Disney, project engineer for ">Integral Group, the mechanical engineer. "You really had to examine every detail."

For example, the HVAC systems must have the precision and data-collection ability of scientific apparatus, but Integral had to specify off-the-shelf components. For an office building, chilled-water supply temperature to a radiant slab is within ±2˚ F of accuracy; for the lab, it has to be within ±0.5˚ F. Integral's workaround, to reduce the water temperature variation, was to specify a buffer tank.

Achieving plug-n-play capability has been especially difficult. "It took a lot of care, planning and meetings to understand the [special] details and more than the usual amount of coordination and cross-team communication," says Overaa's Blankinship.

Building information modeling would have helped, but it was a casualty of the value-engineering, he adds. Only the mechanical contractor used BIM.

The interface of the DAQ elements, especially with the HVAC controls, is a huge effort, says Schaefer. DAQ system designer ">Cal-Bay Systems, a provider of medical-device and other monitoring systems, had no experience with construction submittals. It took a while to work out an approvals process, he adds.

Still, the rotating test bed, not designed by the bid deadline, caused the greatest angst. In most so-called revolving buildings, only the floor rotates around a stationary core that contains utilities, says Stantec's Adams. The Berkeley building has no core.