Sustainability in the Desert: Medical education facility showcases copper design

by H. Wayne Seale, AIA, NCARB
The design of the Health Sciences Education Building (HSEB) at the University of Arizona College of Medicine–Phoenix is inspired by the iconic canyon formations found throughout the state. Made using predominately recycled copper, the medical education building’s façade blends in naturally with its southwestern landscape, resembling the stratified earth layers and majestic canyons for which Arizona is known.¹

Using nearly 6000 copper panels that were fissured, formed, bent, pressed, and perforated, along with more than 10,000 copper components, this massive 24,898-m² (268,000 sf) facility consists of:

• six stories of administration and faculty offices;
• lecture halls;
• learning studios;
• flexible classrooms;
• clinical suites;
• gross anatomy facilities;
• laboratories; and
• conference rooms.

Medical education facility required
Students at both the University of Arizona and Northern University Arizona will have access to the HSEB to support various programs, including the colleges of medicine, pharmacy, nursing, and allied health. The facility will serve as a training ground for 1200 medical professionals annually.

Located within a 12-ha (30-acre) biomedical campus in downtown Phoenix, the building is owned by the Arizona Board of Regents on city-owned land. With a critical physician shortage both in the state and nationwide, there was a growing need to create a medical teaching facility for healthcare professionals to not only learn, but to conduct research as well. Due to economic conditions, the HSEB project faced enormous challenges overcome by using innovative technologies and domestically sourced materials highlighting the sustainable architectural design, elements, and impact.

Several design partners contributed to the project’s overall success, including two architectural firms—CO Architects and Ayers Saint Gross—and two contractors, a joint venture of DPR Construction and Sundt Construction Inc.

Online green learning
The selection and development of a building’s site can support the health of its surrounding community and identifies the positive outcomes of using the integrated design process. Maximizing the integrated design process was essential to the building’s success. It meant assembling a team of experts, including designers, construction managers, and exterior envelope contractors, who understood the project’s goals. The sustainability goals, and resulting performance criteria, were defined early during the schematic design phase. The approach also proved essential in solving the complex configuration of the exterior copper panels.

The integrated design approach affected the cost of the HSEB building. It was only through early collaboration between the design, design-assist, and construction teams that the complex, custom copper panel cladding was realized within the project budget. This would not have occurred in a traditional design-bid-build delivery method.

Leadership in Energy and Environmental Design (LEED) Materials and Resources (MR) and Indoor Environmental Quality (EQ) categories for which the contractor had a primary responsibility during construction. These credits include:

• MR 2, Construction Waste Management;
• MR 4, Recycled Content;
• MR 5, Regional Materials;
• EQ 3.1, Construction IAQ Management Plan–During Construction;
• EQ 3.2, Construction IAQ Management Plan–Before Occupancy;
• EQ 4.1, Low-emitting Materials–Adhesives and Sealants;
• EQ 4.2, Low-emitting Materials–Paints and Coatings;
• EQ 4.3, Low-emitting Materials–Flooring Systems;
• EQ 4.4, Low-emitting Materials–Composite Wood and Agrifiber Product;
• EQ 5, Indoor Chemical and Pollutant Source Control;
• EQ 6.1, Controllability of Systems–Lighting;
• EQ 6.2, Controllability of Systems–Thermal Comfort;
• EQ 7.1, Thermal Comfort–Design; and
• EQ 7.2, Thermal Comfort–Verification.

The roles and responsibilities of various construction team members for the project are related to Energy and Atmosphere (EA) Credit 3, Enhanced Commissioning. This credit entails additional commissioning activities beyond those required in the prerequisite, including the creation of a systems manual for the operating staff and a building operation review 10 months after substantial completion.

Some of the project’s internal and external conditions affect ventilation. EQ Credit 2, Increased Ventilation, requires the building have ventilation rates 30 percent beyond those required by American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) 62.1, Standards for Ventilation and Indoor Air Quality. This is a strategy that can be more easily achieved in the southwest where it is temperate and dry most of the year. Humidity factor is more intense in places like Houston and Miami. However, the HSEB project as a whole did not attempt EQ 2, but the gross anatomy labs do have high air exchanges.

As with most lab applications, dedicated outside air is used. However, HSEB differs from many of its counterparts in the way air is distributed—being brought in above the table, and out below, but energy consumption use was minimized by having the ventilation turned off when it is not in use.

Desert designs
The desert can be relentless and harsh, and the building needed to adapt to its ecosystem. The design for the HSEB was shaped by the Arizona climate with the goal of reducing energy consumption. The building was oriented in east-west wings connected by a north-south axis so it would be shaded from direct sunlight during the summer months.

Windows were eliminated in the east and west wings; instead, deep glazed incisions were made to allow light to flow into the building from the north and south where they could be controlled. Shading devices of numerous geometrical shapes were also installed in varying elevations protecting the glazing on the building so the direct solar radiation hitting it in the summer was minimized, yet the sun’s rays could still be absorbed in the winter to provide some heat load for the building. This contributes to the overall energy savings for the building by reducing the heating and cooling costs.

Shading and daylighting strategies
A geometric shading study, conducted by the project team during schematic design, led to four main design recommendations:

1. Orient the wings in an east-west direction to most effectively control solar gain on the building’s façades.
2. Use self-shading to control solar gain by shaping the façade in three directions, which would entail:

• curving the floor plates along the east-west axis, reducing the amount of sun on the east, half of the south façade in the morning and the west half of the south façade in the afternoon; and
• sloping the vertical façade so the upper floors projected beyond the lower floors.

3. Provide shading devices on all elevations to prevent introduction of direct sun into openings from May through the end of September. South façades could be nearly completely shaded with horizontal devices of various geometries. East and west façades should be as opaque as possible, but if exposed, protected from low and high angle sun by honeycomb or screened structures. North façades receive low-angle summer sun and should be protected by closely spaced shallow vertical fins.
4. The courtyard would require protection from overhead.

The design team adapted the design to these principles. Rather than a smooth curve, the north and south wings were bent into a ‘bowtie’ shape, which achieves roughly the same performance while allowing rectilinear layouts of programmed spaces. Programmatic constraints would not allow the sloping of the vertical wall face, so the sunshade design parameters were modified to compensate.

Next, the team considered the program, daylighting, and views to implement the recommendations for shading and fenestration for each façade. In order to rapidly test various options, climate engineering consultant, Transsolar, developed a simplified approach where an individual model was created for each of the five major space types identified in the building program: offices, classrooms, clinical spaces, gross anatomy laboratories, and circulation. Each space was modeled as an individual, typically sized room within the building with three interior walls, and one exterior wall with 60 percent glazed area. Various combinations of ventilation systems, thermal comfort controls, fenestration, and shading devices were modeled. The thermal simulation of these ‘shoebox models’ was performed using energy modeling software.

Daylighting Optimization
The next design study looked at the effect of daylighting on the design of the façade and composition of the elevations, with the important goal of projecting as much daylight deep into the floor plate as possible. While this first appeared counterintuitive for Phoenix, it was justified by the reduction of electrical lighting loads, and maximizing connections to the outdoors for the building occupants. The team configured shading devices to prevent direct sun from falling on glass from May to September. By using the shading devices as light shelves to reflect indirect light into the building, they also reduced glare. A program was used to show sun penetration and generate sun angle studies to help configure the devices.

Finally, an exterior wall section profile was developed for each of the major space types, configured for orientation, ceiling height, room depth, and room activity. These optimized profiles were then applied to the elevations.

The design for HSEB draws inspiration from Arizona’s mountains and canyons; it responds to the desert climate, characterized by intense sunlight and extreme temperatures. For insight and inspiration, the architects turned to early human settlement in the Sonora Desert, where Native Americans traditionally sought shelter deep within slot canyons naturally created by wind and water erosion. These self-shaded majestic spaces maintain temperatures 8 to 14 C (15 to 25 F) cooler than the ambient temperatures outside.

Taking design elements from the mountainous environment, a canyon-like feature was carved through the north and south wings—which are bent in a bowtie shape—to create an outdoor space within the building. Occupants are protected from the desert heat by an overhead tensile fabric shade structure, the thermal mass of the concrete block cladding, and tempered relief air that is directed through the courtyard rather than exhausted from the air-conditioning system.

A big part of the project was integrating the multitude of copper elements into the overall building design. Numerous innovative construction management and project-delivery programs were developed to exhibit the team’s commitment to lean construction and quality, significantly reducing costly rework and waste.

Construction advances included:

• prefabrication and assembly of the complex exterior copper skin panels on the ground, which were then hoisted into place—improving productivity by 20 percent, by reducing installation time, and eliminating the need for expensive changes;
• building information modeling (BIM) for virtual 3D mockups, allowing all trades full access to the model to develop and coordinate the design of the panels, reduce errors and improve real-time coordination in the field, as well as enable clear review with the owners;
• laser scanning providing a detailed, cast-in-place concrete as-built model, which, when superimposed over the virtual model, allowed the team to resolve issues in a virtual environment before fabrication and installation, thus eliminating rework; and
• software-capable wirelessly networked tablet computers to create a real-time visual rolling completion list system, dramatically reducing time spent resolving quality issues.

Employing copper
The copper wall cladding used for this building is atypical from industry standard flat-panel installations. To meet the design intent, panels had custom shapes with custom folds—some perforated, others not—and the wall assembly was fully engineered for this extreme desert environment. The material is sustainable and changes over time, supporting the aesthetic and functional intent of buildings. Due to its durability, malleability, and high ductility, copper can be formed and stretched into complex and intricate surfaces without breaking.

While the copper will likely remain a brownish hue in this arid environment, its color will begin to change and become variegated over time, seemingly appearing to connect more to the surrounding mountains. The copper cladding for the HSEB is made up of 99-percent recycled material from copper mills. With a recycling rate higher than other engineering metals, the material used for the HSEB panels most likely served as a computer part, plumbing fixture, or wiring system several years ago.

Copper is recycled at different rates depending on the final use. For example, electrical wiring only comes from cathode copper and cannot use recycled material. On the other hand, architectural copper typically has anywhere between 75 and 100 percent recycled material. Mills will typically employ their scrap material first, if enough scrap is unavailable, cathode (i.e. material that has been produced through the mining process) will be used. Also, if an architect is submitting a project for LEED certification, he or she can specify the recycled content of their material. If 90 percent recycled material is requested, the mills will run 90 percent recycled copper.

Kovach Building Enclosures engineered, fabricated, and installed the nearly 2500 custom copper panels for the exterior of the building. Through an interactive, collaborative process in which architects used BIM to generate 3D models of panels, Kovach then fabricated into a series of full-size panel mockups, the team was able to create the appearance of a naturally occurring random pattern, while using only 26 panel types, arranged in multiple combinations.

The panel size and depth balanced visual and performance goals with cost-saving strategies, such as keeping overall panel size to domestically available copper. This project features multiple exterior finishes, including the approximately 113,398 kg (250,000 lb) of copper—most of which is recycled.

In addition to its aesthetic appeal, the extensive copper-cladding provides the HSEB with a skin most suitable for the hot, dry desert climate. With Phoenix temperatures reaching as high as 46 C (115 F), copper is an attractive alternative to steel due to its ability to quickly reject heat. The building’s copper-clad exterior serves as a shield protecting its interior from direct solar exposure.

Adapting rainscreen technology, the building’s design team took a system typically used in the northwest and created a way to use copper cladding as a sunscreen to keep excessive heat out of the HSEB. A fully integrated system consisting of copper panels, a 50.8-mm (2-in.) air space, rigid insulation, and a waterproofing membrane work together to absorb the radiant heat, and allow it to vent out through the building’s top.

Completed in August 2012, the HSEB project targeted Leadership in Energy and Environmental Design (LEED) Silver certification for new construction. Allowing optimal natural light in interior spaces while mitigating heat gain using building siting and advanced materials, the copper exterior meets the objective for thermal performance and durability, while creating an architectural expression unique to the building’s location. At the same time, the use of highly recycled copper honors and respects the state’s abundance of this natural resource.

Conclusion
The HSEB project was integral in boosting the economy through the creation of jobs, both during the construction phase and after the medical facility opened. Approximately 250 design, engineering, and construction jobs, as well as 33 permanent research positions, were created. The overall project is estimated to have an initial economic impact of $27 million. Studies produced by the owner and contractor have indicated the average return on investment of such projects is seven times the initial cost. Approximately 83 percent of metal, wood, cardboard, gypsum, and inert materials were also diverted from the landfill during construction.

The HSEB was recognized with a North American Copper in Architecture Award (NACIA) by the copper industry this year. It was one of 14 projects to be honored for its architectural design, detail, and craftsmanship.

Notes

¹ A two-part video documentary produced by the Copper Development Association (CDA), in conjunction with design professional online resource, GreenCE, showcases the materials and craftsmanship of the HSEB project, as well as the philosophy and strategy behind the facility’s sustainable design and construction. Both CDA hour-long videos are registered with the U.S. Green Building Council (USGBC) for continuing education credits and with the American Institute of Architects (AIA). The resource can be accessed at www.greence.com. (back to top)

H. Wayne Seale, AIA, NCARB, is a project manager for the Copper Development Association (CDA) specializing in architectural and plumbing applications. He is an architect registered in New York State and holds a Master of Architecture degree from Virginia Tech along with a BA in Business Management from Minot State University. Seale has been employed by CDA for more than 16 years where he serves as a technical resource in the application of copper and copper alloys on and in buildings and he teaches architects how to design, detail, and specify copper systems. Seale can be reached by e-mail at wayne.seale@copperalliance.us.