|Central College, in Pella, IA, and The Weitz Company have already teamed up to build the state's first LEED certified Silver and Gold projects and are aiming for Platinum certification on the school's new Education and Pyschology Building. (Rendering courtesy of RDG Planning & Design)|
An Iowa college and an Iowa construction company, each founded more than 150 years ago on what was then still the frontier, are modern-day pioneers of sustainable building.
Central College, founded in Pella in 1853, and The Weitz Company, established at Fort Des Moines in 1855, are Iowa's undisputed "green" building leaders, working together for a decade to construct increasingly energy-efficient and environmentally friendly projects on the private school's campus.
After incorporating many green elements into the Weller Center in 1999 and a biology field station the following year, Central College and The Weitz Company teamed up in 2003 to build the state's first Leadership in Energy & Environmental Design (LEED) certified Silver project, the Vermeer Science Center. They quickly followed that achievement with Iowa's first LEED certified Gold project, Howard McKee Hall in 2005.
Now pushing their experience and expertise to an even higher level, the partnership is pursuing a green trifecta, aiming to earn the state's first Platinum rating for Central's new $17-million Education and Psychology Building to be completed this summer. To garner Platinum, LEED's highest certification so far achieved by fewer than 70 structures worldwide, they are incorporating numerous special, non-typical systems and materials into the three-story, 56,000-square-foot design that features 13 classrooms and 22 offices.
Because the planning and coordination vital to the success of any construction project take on even greater significance when building for certification through the U.S. Green Building Council's LEED program, Central and Weitz, along with their design partners, spent several weeks analyzing the costs and benefits of different building options.
"You can't decide you want to build green halfway through a project," says Chris Harrison, senior vice president of The Weitz Company's Iowa business unit. "Building for LEED certification is a very proactive process and the owner, designer and contractor have to be on board early, thinking about the construction elements and documentation required."
"It has been a very integrated, collaborative process," says Mike Lubberden, Central's director of facilities planning and management, and a LEED accredited professional (LEED AP). "The Weitz Company has been with us from the project's inception, helping us with schematic pricing and using their experience to give us feedback on cost and building implications. Their expertise was invaluable as we put all the information together in the design process."
To earn a LEED designation at any level, a project has to score a specified number of points in six environmental categories, explains Steve Heyne, LEED AP, The Weitz Company's project manager for the Education and Psychology Building. "On a Platinum project, you have to go after nearly every point possible and that requires a lot of research and planning. There are some things that, intrinsically, you can't go after," says Heyne. "This isn't a Brownfield site, for instance, and we don't have mass transit in the area, so we can't try for those. But we researched all the options and we are going after some points we haven't pursued in the past because we need a higher score to earn the Platinum rating."
Some of those additional points include scoring for rapidly renewable materials, certified wood products, and water use reduction. The team also hopes to boost its point total with a stormwater design that includes a green roof and reduces the building's flow rate to less than the rate of the pre-developed site. Scoring higher on innovative wastewater technologies, energy performance, thermal comfort, and daylights/viewing will also be critical to their final tally.
In all, Heyne says, Central and The Weitz Company think they have up to 10 "new" points on this project that could help them achieve the Platinum rating.
Of all the elements selected for the final design, Heyne notes that the choice of radiant flooring had the biggest impact on the building's shape and look. "Using the radiant floor to maximize heating and cooling efficiency drove the slab system," he says. "It's a precast plank with insulation and then a tubed, concrete floor on top."
On the mechanical side, the use of radiant flooring meant a reduction in duct sizes. And the use of precast slabs associated with radiant flooring allowed long spans for large, open classrooms.
The precast and block structure on poured foundations also includes operable windows that play a significant part in the heating/cooling of the building as well as providing "daylights/viewing" in nearly all of its spaces.
Other features that enhance scoring in LEED's Energy/Atmosphere and Indoor Environmental Quality categories include light shelves and photocell automation control. The light shelves, coupled with sloped, reflective ceilings, allow natural, indirect light to penetrate deep into the building, thus reducing the need for artificial lighting. The building automation system is being utilized to provide a daylight harvesting strategy that will dim fluorescent lighting while allowing building operators to adjust parameters and ensure that the systems are operating to their design intent.
The use of recycled products is another important aspect of the non-typical construction used throughout the building and includes high-recycle content concrete that is a 50-percent mix replacement with slag or fly ash. "We usually don't go above 20 percent on replacement," says Heyne. "The workability is similar to standard concrete, but the curing time is longer."
Rebar used on the project is 100-percent recycled steel, and the rolled steel building components are 70-percent recycled. Sheet glass in the building is 20-percent recycled, and the aluminum for glazing is made from 70-percent recycled materials.
Other products with significant recycled content include work area countertops made with shredded U.S. currency and plastic resin; paneling and cabinets made from wheat stock or recycled wood fibers and resin; and plastic partitions made from 100-percent recycled materials. The building's doors and carpet also have recycled content.
"Sustainability" has also been carried through to other, more aesthetic elements of the building, as a walnut tree taken down to make way for the project is being recycled into a work of art that will grace the building's entryway. And, in addition to other works of art throughout the building and along the stream featured in its landscaping, Central's commitment to sustainability will be highlighted by a computerized learning station in the lobby. The touch screen kiosk will provide information on the building's green features as well as real-time data on how the building's efficiencies benefit the environment and reduce costs.
"That ties together with the whole idea of sustainability and looking out for the planet's future," notes Lubberden. "As an institution, Central College has recognized the importance of how its facilities can be integrated into programs at the college. Sustainability is part of the core curriculum, and we will use buildings like this as a part of our students' education."
The work is on schedule for The Weitz Company, which Heyne says is self-performing "everything concrete and wood" on the project. They plan to complete construction by about mid-July so Central will have time to commission the building and move in before fall classes begin.