University Buildings that Educate
Educating Wisconsin
by Bill Odell

Solar energy contributes to energy efficiency for a new building at the University of Wisconsin-Green Bay.

The University of Wisconsin-Green Bay needed a new building to house additional classrooms and provide more space for offices and special programs.

The state wanted to make the project a model for energy conservation. The goal was to reduce energy consumption for heating, cooling and lighting by 50% compared to similar buildings. The state also wanted to promote the potential environmental and economic benefits of renewable energy resources. In accordance with its strong environmental studies program, the university wanted the building to strengthen its focus on environmental issues. All this needed to be achieved without sacrificing functionality or compromising the university's space needs.

Working through the US Green Building Council's LEED (Leadership in Energy and Environmental Design) Green Building Rating SystemTM as a design guidance and decision-making tool, the St. Louis office of HOK and Somerville Architects of Green Bay designed a facility that will team an abundance of light with one of the most energy-efficient buildings ever constructed.

Environmentally Responsible Design
Lighting and energy weren't the only focus of the design team. Both indoors and out, numerous other areas of the building will also showcase its environmentally responsible design.

Interior Design
Materials proposed for the interior include:

• Hebel Block: This aerated, autoclaved concrete building unit can be load-bearing and weighs significantly less than a concrete masonry unit. Energy-efficient features include a high R-value and low energy production.
• Carpet: HOK's design calls for the carpet to have a high percentage of recycled content and to come from manufacturers with reclamation and recycling programs.
• Linoleum: This flooring product is made from biodegradable, 100% natural materials: linseed oil, rosins, cork and wood flour.
• Adhesives: Adhesives are water-based and low-VOC.
• Cork: Cork offers good acoustics, comfort underfoot, is water resistant, and is easier to maintain than carpet. It originally was considered for specialty classroom floors.
• Bamboo: Bamboo is used as a demonstration product in place of typical wood flooring in conference rooms and gathering spaces.
• Ceramic Tile: The specified ceramic tile has more than 60% recycled-content, post-industrial feldspar waste as its primary raw material. The manufacturing process is a closed system for
  solid waste accumulation and reuse.
• Gypsum Board: This wallboard material uses recycled content gypsum and kraft paper. It currently is an industry standard.
• Acoustical Ceiling Tile: This tile is made of recycled cellulose and mineral slag. It, too, is an industry standard.
• Panel Fabric/Upholstery Fabric: This is specified to be 100% post-consumer recycled polyester from soda bottles.
• No Ozone-Depleting CFCs, HCFCs, or Halon are used in tile mechanical systems. Building materials have been selected to reduce or eliminate CFCs and HCFCs from the manufacturing process. Additionally, the building's mechanical systems have been designed to meet ASHRAE Standard 62, the industry standard for indoor air quality. The team selected materials that provide a healthy interior working environment by minimizing VOC-offgassing, microbial growth and particulates.

Exterior Design
One of the reasons the team chose this site was for the opportunity to create a campus quadrangle. Completing the final side of the existing quadrangle with a building creates a wind-protected
area that should encourage students to gather outdoors during mild temperatures.

• Landscape Materials: The entire building site will be planted with low-maintenance native plant materials. Creation of a central courtyard extends the existing arboretum into the campus core.
• Stormwater Reclamation System: A rainwater harvesting system has been proposed for the courtyard demonstration area. If incorporated, this system will capture rainwater for irrigation and
  non-potable use.
• Construction Waste Management: The team hopes to reduce construction waste by 90% compared to standard practices. Working with a state waste reduction office - which will be one of
  the building occupants - the team prepared a detailed construction waste specification.

Additional design features awaiting private funding include demonstration gardens, constructed wetlands, and an interior "living wall" made up of plant life that acts as a natural biofilter for
cleaning air and as a "living machine" for purifying water.

Renewable Energy Focus
To capitalize on renewable energy sources, two building-integrated photovoltaic (BIPV) systems were specified for the building's design. Harvard, MA-based Solar Design Associates was retained to help the design team define the BIPV options and provide design and engineering for the systems.

The first system integrates thin-film PV technology laminated to standing seam metal roof panels. Developed by United Solar Systems of Troy, MI, the thin-film PV lamination will soon be available in a field-applied format to be installed on-site once the metal roofing has been set in place.

This approach was selected because the majority of "conventional" roof surface on the building was specified to be standing-seam metal roofing, and the application of the thin-film PV laminates was considered a perfect fit by both the owner and the design team. The standing-seam BIPV roof will generate some 18,000 kWh annually.

The second BIPV system employs a thin-film-on-glass PV technology that forms the major roof element over the winter garden as well as part of the vertical south-facing glass curtainwall. Developed by BP Solarex, this thin-film material is vacuum-deposited on a glass superstrate, which is then laser etched to provide light transmission. (See "Specifying Building-Integrated Photovoltaics" on pages 20-24 in this issue).

The etched thin-film PV is then combined with standard glass to form an insulated glass element, which provides the same thermal and structural features as conventional architectural glazing. The laser-etched thin-film BIPV atrium and south curtain wall will, together, generate some 13,500 kWh annually.

This project is the first commercial use of this novel laser-etched thin-film technology in the United States. These new products will become commercially available later this year. As volume grows and the cost of transparent thin-film PVs continues to decline, SDA's Steven Strong predicts that every building surface will become eligible for solar power generation - including vision glass. "In the not-to-distant future," says Strong, "architects will selectively specify the desired degree of light transmission, thermal integrity and solar power production from a new generation of solar electric glass as thin-film PV's become more sophisticated and begin to displace high-end architectural glazing."

With the considerable requirement for heating outside air during winter, the designers had the opportunity to reduce energy consumption even further by using solar energy to pre-heat ventilation air. The team chose to integrate a low-cost solar pre-heating system developed by Conserval Systems of Buffalo, NY, and the National Renewable Energy Laboratory. Known as a transpired air solar collector, the system is a perforated metal collector painted black to absorb solar radiation. Convection draws the intake air through the perforations into the cavity behind. There, the solar-heated metal panels pre-heat the air and it enters the building many degrees warmer than the outside air. These panels make up the finished portion of several sections of the building's south exterior wall.

Internet Site and Multimedia Kiosk
The project team has approached the entire building as a tool for enhancing the university's educational mission. In keeping with this mission, the building is being designed to display and explain these features to the building occupants through multimedia kiosks and an Internet site.

The main building entry provides a "museum" orientation and demonstration area to teach building users and visitors about the building's environmental mission. Electronic kiosks and other displays will provide real-time and historical reports showing the current and accumulated contribution of solar power through daylighting and photovoltaics.

The proposed Internet site will present multi-layered, multi-tracked information about the building and its programs, with a focus on building-integrated photovoltaics, daylighting, and the solar wall (transpired solar collector/make-up air pre-heat). The site would employ a live web-camera to "broadcast" construction images, again emphasizing images of the building-integrated photovoltaics, daylighting and solar wall features.

The design includes an interactive multimedia kiosk for presenting information about tile building-integrated photovoltaics and daylighting technologies. The kiosk, located in the winter garden area, would display the building's real-time and historical energy performance.

Energy Conservation Techniques
In addition to the use of solar energy, other main energy conservation strategies attempt to decrease those loads. DOE-2 energy models indicate that the building's energy consumption will be 60% less than permitted by the Wisconsin Commercial Building Energy Code.

• Energy Modeling - Led by the team's energy and daylighting consultant - Architectural Energy Corporation (AEC) of Boulder, CO - the team created a hypothetical "reference" building design. AEC created a series of elimination parametrics to evaluate the overall impact of each building component, including lighting, people, equipment loads, ventilation and skin. This provided an initial set of energy conservation targets. The team then conducted an iterative process of elimination parametrics and conservation strategies until reduction strategies were rendered meaningless. Early parametric figures indicated that heating energy required for ventilation air in the classrooms represented the single largest component of the baseline building's annual energy performance. The next-largest component was for lighting energy. The design team thus focused on ventilation and electric lighting as the two biggest opportunities for energy savings in the initial approach to energy conservation. AEC built two daylighting test models with changeable parts so that different strategies and design elements could be studied as the building design developed. The university's director of buildings and grounds, along with key staff members, were involved in all aspects of the programming and design. This familiarized the owner with operations and helped them understand the best, healthiest maintenance systems for the building they are poised to inherit.
• Controlled Ventilation - Ventilating the classrooms requires a great deal of energy. To reduce this load, the building automation system will be re-programmed each semester to reflect the new class schedules. Ventilation will only be supplied to these classrooms when class is in session. A manual override equipped with a timer will accommodate unscheduled gatherings.
• Building Envelope - The team designed the exterior building envelope with a high R-value for walls and windows. To reflect the different orientations, the windows on all four sides have different transmission characteristics. All glass is gas-filled and has a low-E coating. The building exterior walls will be approximately R-35 and the roof will be approximately R-50. High performance low-E glazing reduces solar heat gain during summer months and heat loss during winter months. The glazing also plays an important role in ensuring visual comfort throughout all the building's daylit spaces.
• Mechanical Systems - An outside air economizer cycle will supply outside air for cooling and ventilation during summer months or when outside temperatures permit. While operable windows were considered and rejected, the outside air economizer provides "free cooling" in much the same way, delivering 100% outside air when temperature and humidity permits.
• Daylighting - Both the architectural program and preliminary energy modeling identified the use of daylighting as a potentially significant energy conservation measure. Daylighting strategies had a considerable impact on the building's shape and space configuration. The design maximizes access to perimeter surface areas and rooftops for light monitors. Daylight supplies most of the building's ambient lighting. To capture the high-quality northern light, all the major classrooms are designed with east-west light monitors. Motorized blackout shade panels are available for times in which classes need to use audiovisual equipment. Faculty offices are daylit from clerestory windows and from borrowed light. All major circulation spaces are daylit, ensuring that users rarely lose sight of the outside. Designed in the 1960s, the University of Wisconsin-Green Bay's original campus has a below-grade tunnel system connecting all the buildings. Dubbed by the design team as "Main Street," these tunnels will be glazed to provide light and a visual connection to the lower level quadrangle created between the new building and the existing library and student center. The existing campus tunnels, by comparison, have very little glazing or natural light, making wayfinding among buildings difficult. The top-lighting systems in classrooms are designed to provide stable daylight harvesting and even, ambient light coverage. Light shafts beneath daylighting apertures use specific geometries to optimize incoming light, which is diffused by a suspended, curved, perforated metal plane that redirects the light across the ceiling plane. The result is an illuminated ceiling that provides sufficient general lighting without using the electrical fluorescent fixtures. A series of daylight models were constructed to test and refine the daylighting strategies. One model featured the building's large lecture hall with a north-facing daylight monitor. The other model was of a southern office and classroom wing. This model included a medium-sized classroom with south-facing daylight monitor and office areas with a central clerestory daylighting system.
• Electric Lighting - Most of the building's electric lighting is controlled by occupancy sensors. To maintain classroom lighting levels, the design incorporates a combination of daylighting and electric lighting with dimmable electronic ballasts. Photocells measure daylight from the overhead monitors. On a bright day, this system will turn off unnecessary lights. On overcast days or evenings, the system will dim the lights and adjust the fluorescent fixtures to the required light level. Ninety percent of all lighting fixtures are fluorescent, which provides efficiency, easy maintenance and a long lifespan. Indirect/direct fluorescent pendants provide an illuminated ceiling of ambient light and direct tabletop light. These lamps have a lifespan of 20,000 hours, which means they will only need replacing once every three years.

Building Orientation
Designed in the 1960s, the University of Wisconsin-Green Bay's original campus has a below-grade tunnel system connecting all the buildings. The new building extends partially
underground to connect the library and student union at the tunnel level.

A below-grade level, dubbed by the design team as "Main Street," accommodates most of the circulation. The below-grade concourse connecting this building to the rest of the campus is glazed on one side to provide views to the central grassy quadrangle. The existing campus tunnels, by comparison, have very little glazing or natural light, making wayfinding among buildings difficult.

The new building will house 20 classrooms, or about half the classrooms on campus. It also will provide space for a variety of academic and community programs, special natural science collections, faculty offices, display spaces, and common support areas. The building also will serve as a visitor orientation area and as a new center for campus life.

The building is organized around a central courtyard, which gives a sense of orientation for the users and provides daylight into all major circulation spaces. This are also serves as the natural science demonstration gardens.

The first floor contains classrooms and special program offices. Additional classrooms are in the building's lower tunnel level, which opens to the central quadrangle. Many classrooms have interior windows to the corridor that provide an opportunity to showcase "learning as an exhibit," which is one of the chancellor's goals.

The second floor primarily houses faculty offices. Special collection areas that require completely controlled environments are located in the only true basement space.

Economics
The total base construction budget for the project is $14 million: $12 million in state funds and $2 million in private donations. With the tight budget and a difficult site, the design team's first priority was to satisfy the university's space needs. Even so, most of the sustainable features were achieved within the base budget.

The local utility, Wisconsin Public Service, funded the photovoltaic panels to research this technology and to investigate the effectiveness of distributed power generation in this northern climate.

The energy model predicted that extensive daylighting could create energy savings in excess of $18,000 per year. The proposed daylighting strategies will thus pay for themselves in approximately five years.

The team evaluated each energy conservation feature on a life-cycle basis and implemented many. The payback analysis was complicated by the fact that the state of Wisconsin pays all utility bills directly, so the university had no direct financial incentive to include energy conservation measures. As a result, the university has recommended that the state change this administrative procedure to give users financial incentives to conserve energy.

Benefits of the Design
The design provides users with a light-filled facility in which learning and working should be a pleasure. Yet these same characteristics also combine to create an extremely efficient building.

In addition to serving as a statewide model for energy conservation, the building will showcase various methods of environmentally responsible design. By demonstrating various sustainable design technologies, the building becomes part of the pedagogical mission of the university's environmental studies program. As designed the building qualifies for a "Gold" award (through LEEDTM) on this project.

The Design Process
The university developed an initial program for the building. Before beginning design, the team verified this program and made the necessary changes. The university's proposed move-in date combined with the state's extensive review process created a fast-track design schedule.

The design process began with a four-day charrette in April 1998. During this brainstorming meeting, the team met with university faculty, students, and staff to discuss design goals, tour the site and develop initial concepts.

Over the next two months, the team refined the design options based in part on a series of public meetings, energy model evaluations, systems development studies, and site analyses. The university selected a final scheme in late June 1998.

As part of this design workshop, the team created a DOE-2 energy model and discussed energy conservation ideas. These early studies were an important part of the conceptual design. The model was updated regularly as the design progressed.

Led by the team's energy and daylighting consultant - Architectural Energy Corporation (AEC) of Boulder, CO - the team created a hypothetical "reference" building design based on the architectural program and current practice levels of energy efficiency as defined by the Wisconsin Commercial Building Energy Code. After acquiring Green Bay climatological data and information about local utility rates, the team used DOE-2 building energy analysis software to simulate energy use and costs. AEC created a series of elimination parametrics to evaluate the overall impact of each building component, including lighting, people, equipment loads, ventilation and skin. This provided an initial set of energy conservation targets.

Once strategies were in place to deal with these loads on the building, the overall profile of the building energy consumption would change. As the initial high energy components were lowered, other areas became important in the overall energy use of the building. The team would then initiate another set of elimination parametrics and conservation strategies. The team repeated this iterative process until reduction strategies were rendered meaningless.

Early parametric figures indicated that heating energy required for ventilation air in the classrooms represented the single largest component of the baseline building's annual energy performance. The next-largest component was for lighting energy. The design team thus focused on ventilation and electric lighting as the two biggest opportunities for energy savings in the initial approach to energy conservation. AEC built two daylighting test models with changeable parts so that different strategies and design elements could be studied as the building design developed.

The university's director of buildings and grounds, along with key staff members, were involved in all aspects of the programming and design. This familiarized the owner with operations and helped them understand the best, healthiest maintenance systems for the building they are poised to inherit.

Bill Odell is design principal at HOK and is director of their Sustainable Design Group.

From the March/April 2001 issue of Environmental Design and Construction (www.edcmag.com):

First BIPV System Installed at University of Wisconsin - Green Bay
The first building-integrated photovoltaic (BIPV) system - a thin-film PV laminate from United Solar Systems Corp. (USSC) on standard metal roofing - has been installed in the University of Wisconsin-Green Bay's new academic building (designed by architects Hellmuth, Obata + Kassabaum, St. Louis, MO).?

A second BIPV system will be installed as a major roof element over an atrium. This system will be the first US application of laser-etched, semi-transparent, thin-film PV as an insulated-glass element in an architectural glazing system. The atrium will feature a semi-transparent PV roof, as well as PV in the upper segment of the south curtain wall. Harvard, MA-based Solar Design Associates is heading the BIPV installation.

For additional information:
http://www.buildingsolar.com/

This document was last modified on 02/20/2002 10:43:02 AM