Blue Cross Raises a Green Shield
Health and well-being are the stock in trade of Wellmark Blue Cross and Blue Shield, so it should come as no surprise that the insurer's new $194-million headquarters in Des Moines, Iowa, comes equipped with ergonomic workstations, a fitness center and a restaurant that eschews sugar highs by offering low-cal pies.
But this sprawling campus-like facility goes the extra mile—and then some. In a nod to the millions of people it insures, Blue Cross has fashioned a headquarters whose systems not only take into account the welfare of employees, but the overall environment at large—and those who inhabit it.
The result is said to be the largest wholly owner-occupied office building in the world to receive LEED-Platinum certification, a designation that Iowa Gov. Terry E. Branstad (R) characterizes as "a tremendous accomplishment for both Wellmark and the entire state of Iowa."
Serving some 1,600 employees, the four-story, 852,000-sq-ft facility saves more than 20% in energy costs and reduces overall water use by more than 50% as a result of systems ranging from under-floor air distribution, which promotes better management of heated and cooled air, to what is thought to be the largest gray-water system in the country. The assembly reclaims rainwater from roof drains, ground water from a subsoil drainage system and condensation from mechanical equipment and diverts it to toilets and urinals. Along with low-flow fixtures, the system saves 2.4 million gallons of water a year by routing reclaimed water through below-grade filters, then directing it to a 50,000-gallon below-grade flushing cistern.
"The system is made from fairly standard components, but they've never been used in tandem for an assembly this large," says Andy Thielen, project executive with KJWW Engineering Consultants, Des Moines, the project's mechanical engineer. "You could say we were blazing a new trail."
Mindful of the relationship between operating costs and health-care costs, Blue Cross required a 10-year payback on the system and its other environmentally minded investments, whether they pertained to water and energy usage or indoor air quality, says Gaute Grindheim, senior project manager in the Chicago office of architect-engineer HOK, the project's designer.
With assistance from Minnetonka, Minn.-based Weidt Group, an environmental consultant, the project team performed extensive energy modeling and cost-benefit studies as they evaluated site orientation and possible envelope, mechanical, power, water usage and waste-management systems.
"It was an iterative process," recalls Thielen. "What were the advantages of a large central air handler versus a series of smaller distributed ones, a central plant versus a distributed system?"
As the design progressed, project team members employed building information modeling to assist in clash detection, particularly for ductwork and a siphonic roof-drain system that captures rainwater.
The environmental plan, submitted to the U.S. Green Building Council for LEED consideration at the end of design development, was not without compromises, says Matt Brown, Wellmark project manager.
"LEED requires that 75% of interior spaces achieve 25 foot-candles of natural daylighting, but we couldn't hit it," Brown recalls. "With our shading coefficient, our plan came to 73.6%. Had we gone higher, the resulting heat gain would have increased our chiller's operating costs."
Although Brown pored over spreadsheets to keep track of LEED points won and lost, it was only as construction was nearing its final lap that it became clear that Wellmark was within reach of LEED Platinum. "Our initial objective was to achieve LEED Gold," says Brown. "Once we realized we could achieve LEED Platinum, it became a matter of taking a more active role in managing all of those pieces."
With the design set, many of the remaining pieces fell under the purview of the project's general contractor, the Des Moines-based Weitz Co., a firm better known for large-scale headquarters than LEED-certified projects.
"Weitz learned quickly," says Grindheim. "Nearly 90% of construction waste was diverted from the landfill."
Blue Cross, meanwhile, revisited the issue of performance verification, a LEED criterion it had previously rejected. "Even our consultants couldn't figure it out—the number of submeters required to measure electrical consumption or the format for reporting results," says Brown. "Finally, someone from Weidt Group stepped up and said, 'This is how you do it.'"
In addition to environmental health, the completed facility promotes employee health and well-being. Each work space is equipped with dedicated temperature controls and air diffusers, while the introduction of outside air is regulated by CO2 sensors.
"We're a health insurer," says Brown. "What could be more important than the physical and emotional health of our employees and customers?"
Key Players
Owner Developer: Wellmark Blue Cross and Blue Shield, Des Moines, Iowa
Lead Designer: HOK, St. Louis
GC/CM: The Weitz Co., Des Moines, Iowa
MEP Engineer: KJWW Engineering Consultants, Des Moines, Iowa
Submitted by: KJWW Engineering Consultants
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