continued

The six LEED categories, encompassing conditions external to the building such as site selection and transportation, as well as more obvious internal features like energy efficiency, reward a comprehensive approach to sustainable design rather than a single focus. Rinker Hall performs across the board, with particularly elegant solutions to water and energy efficiency, interior daylighting, and waste reduction.

The client selected the site, a former parking lot, in part because of its proximity to public transit service. For those who choose to ride bicycles, there is ample bike parking and even a shower.

Material Use and Reuse

The design team carefully considered how materials would be discarded and new materials incorporated into the project. Before construction began, Centex-Rooney Construction Company of Jacksonville, Florida held training sessions on green building practices for their subcontractors. They arranged for the demolition contractor to reuse the old asphalt and limestone base from the former parking lot.

They also returned drywall debris to the manufacturer for reuse on other projects. The contractor determined that over 50 percent of construction waste was recycled or reused through the waste management plan.

An emphasis on local (within 500-miles, or 800 kilometers) materials reduced transportation fuel costs and helped support the local economy. Also used throughout the building were materials with recycled content such as aluminum wall panels and glazing systems, railings, and ceiling tile. In addition, the architects chose wood from sustainably-managed forests and other materials with renewable content, such as wheat board and linoleum. Rinker Hall's structural steel, metal wall panels, drywall, and ceiling systems will all be recyclable at the end of the building's lifetime.

Relying on Nature

Water conservation was also important for the project. Reclaimed water maintains the landscaping. Low-flow sinks and toilets and waterless urinals lower consumption, and a rainwater harvesting system is used to flush the toilets. All told, Rinker Hall uses 30 percent less water than a conventional building.

Rinker Hall's lighting system also takes advantage of natural processes. Daylight is optimized, which also reduces the mechanical cooling load. A series of skylights along the building's spine bathes classrooms and hallways in natural light. At night, low-energy fluorescent lights illuminate the interior. Motion detectors and daylighting sensors keep electric light use to a minimum.

Custom low-e glazing and interior louvers filter the strong Florida sun and control heat gain and glare. "Light is moved through the space by light louvers, sloped ceilings, and light-reflecting wall surfaces," explains Rae. The building achieves a 17 percent savings in energy consumption through orientation and daylighting.

High-Tech at Work

An efficient HVAC system maintains a comfortable indoor environment using an enthalpy wheel that takes advantage of air that has already been cooled or heated. During the summer, the enthalpy wheel preconditions the incoming hot, moist outside air with the already cooled, dry return air. The preconditioned air is then sent to the air handler and cooled further by the air conditioning coils. In the winter, the opposite occurs as cool outside air mixes with preheated return air.

Additional energy savings comes from the Energy-Star-rated white thermoplastic polyolefin (TPO) mechanically fastened roof membrane. This roofing material produces fewer harmful chemicals than other low sloping roof options, and its light color reflects sunlight, reducing the amount of heat that's absorbed by the building. The total combined energy conserving features provide a 47 percent energy savings.

Rinker Hall's green attributes exceed those outlined by current USGBC criteria. The architects minimized material use and maximized future flexibility, two moves not awarded points by the LEED system. They made a point of avoiding carcinogenic and hazardous materials such as polyvinylchloride (PVC) typically found in energy-efficient windows and furniture, and urea formaldehyde, found in interior plywood and medium-density fiberboard (MDF). (The USGBC advisory committee asserts the danger of PVC has not been proven.)

Despite the high LEED rating, the architects are careful to note that this doesn't necessarily indicate good design. Rae says: "We believe that LEED is a great measurement tool, but it should not be confused as a design tool. There is no substitute for truly holistic, integrated sustainable design."

While Rinker Hall stands on its own as an exemplary green building, its larger significance is as a representative of a campus-wide effort towards cooperation, diverse connections, synergy, and the exchange of information among the building trades.

It makes sense to implement the changes proposed by LEED and other ecological incentives on a communal scale. Relying on local networks for goods and services is key to any sustainable practice. Creating more buildings that serve and support a sustainable framework is a welcome trend and a clear opportunity for universities and municipalities to mitigate their impact on the environment.

Discuss this article in the Architecture Forum...

Lauri Puchall is an architectural designer and writer living in Berkeley, California. She is a member of the editorial board of the San Francisco chapter of the American Institute of Architects, and former managing editor of LINE, the journal of AIA SF.

Rinker Hall, designed by the Croxton Collaborative and GouldEvans. Photo: Timothy Hursley Daylit classroom. Photo: Timothy Hursley Skylights illuminate with indirect sunlight. Photo: George Cott Rinker Hall, level 1. Image: GouldEvans Rinker Hall, level 2. Image: GouldEvans Rinker Hall, level 3. Image: GouldEvans Rinker Hall, site plan. Image: GouldEvans   Click on thumbnail images to view full-size pictures.