Credit: Eckert & Eckert

STEPHEN EPLER HALL AT PORTLAND STATE University, Ore., has been the subject of ongoing studies since its completion in 2003. It is PSU’s first project to receive LEED Silver certification from the Washington, D.C.-based U.S. Green Building Council, the first mixed-use LEED-certified building in Portland and a social experiment in how well users adapt to energy-saving strategies. Monitoring energy and water use has shown that Stephen Epler Hall has been successful in achieving significant savings. Seattle-based Mithun further has examined the building’s performance from the perspective of students, faculty and staff who use the space. The results were compared to the design goals established by PSU and the design team, measuring the project’s ability to encourage environmental stewardship in conjunction with its high-performance goals.

CONTEXT

Credit: Eckert & Eckert

Stephen Epler Hall is a 6-story, 130-unit student residence situated over ground-level classrooms and faculty offices. Located on a campus in downtown Portland, the mixed-use building is well positioned for urban strategies. It is close to multiple transit options, including bus, light rail and streetcars. The design carefully integrates energy conservation into the building’s structure and the high-performance systems are exposed to increase awareness and learning opportunities.

The project represents a new direction in campus expansion—accommodating increasing numbers of students while reducing the carbon and economic footprints of new buildings. Part of the design’s innovative strategy was to combine residential, classroom and office functions into one location to integrate the campus’ goals for education and sustainability.

Stephen Epler Hall’s resource-efficient strategies include natural ventilation, daylighting and water harvesting. Each façade responds specifically to its solar orientation, and well-insulated studio apartments are primarily heated with body warmth, room lights and the heat generated by a computer. Simple baseboard heating is provided for backup. The project began as a model to showcase PSU’s sustainability program, which states the university’s desire “to be an internationally recognized urban university known for excellence in student learning, innovative research, and community engagement that contributes to the economic vitality, environmental sustainability and quality of life in the Portland region and beyond.”

ASSESSMENT

Many questions have been raised about the effectiveness and financial feasibility of sustainabledesign methods. Will the buildings perform to the energy- and money-saving levels that were anticipated by the designers and clients? Do the buildings meet the functional and behavioral needs of the people who use them? Is comfort and functionality compromised or enhanced by sustainable strategies?

Since Stephen Epler Hall opened in 2003, Mithun has tracked the building’s performance through feedback from PSU and its property manager, Portland-based College Housing Northwest. One year after its completion and achieving LEED Silver status, Cathy Turner, a PSU graduate student in environmental management, conducted a financial analysis for the Cascadia Region Green Building Council, the Pacific Northwest’s USGBC chapter, to investigate energy and indoor water usage in relation to initial modeling and existing commercial building averages.

Turner’s study notes that the storm-water collection and recycling components don’t contribute as significantly to the water-conservation strategy as the high-efficiency water fixtures. Nevertheless, the innovative rainwater-harvesting system was awarded a $15,000 Emerging Technology Grant from the City of Portland Office of Sustainable Development’s G/Rated Program in recognition of its groundbreaking achievement.

Credit: Mithun

According to Turner, in 2003 the design and construction costs for Stephen Epler Hall totaled $10 million. That figure included a net investment in water- and energy-conservation features after receipt of conservation grants and incentive payments of about $290,000. If savings from lower water and energy usage continue at their initial levels, they will generate a return on investment worth more than $700,000 during a 25-year period and an average annual return of approximately 14 percent. Furthermore, Turner’s research reveals that a rebate received from the city of Portland for storm-water reduction strategies would raise the water ROI to a much higher level. Local code estimates average water use to be 7,990 gallons (30245 L) per person per year.

The actual water use for Stephen Epler Hall has been measured at 5,808 gallons (21986 L) per person per year, which is 27 percent less than a comparable building built to code. That figure is based on 130 occupants in the building. Stephen Epler Hall’s first-year water savings allowed PSU to obtain a $79,000 reduction in the system-development fees levied by the city of Portland on new constrution. This reduction will more than cover the intial costs of the water-conservation features on the building. With the rebate factored in, as well, the ROI increases significantly to 19 percent. As energy costs increase, it is clear the strategy pays off handsomely for the institution. In addition, Stephen Epler Hall consumes 44,000 Btus per square foot—considerably less than the 86 kBtu per square foot specified by Oregon code.

POE 360

With confirmation of the building's technical success, Mithun wanted to evaluate Stephen Epler Hall’s performance with respect to the functions, behaviors and experience of the end users. In 2007, the firm developed a post-occupancy evaluation methodology called POE 360 that community stakeholders, every category of end user and the building itself.

Approximately 40 people were interviewed during the course of two months. This collection of data provides a multidimensional picture of a sustainable project interacting with the environment as an entity in its own right—a machine, place to live and work, and part of the urban fabric of PSU and the city of Portland.

THE HUMAN RESPONSE

College Housing Northwest and PSU commissioned the design team to build housing that responded to market research showing that efficiency apartments with a kitchen and bathroom in each would appeal most to PSU students. The studios have proven to be popular among PSU students seeking on-campus housing, and Stephen Epler Hall has been operating at full capacity since it opened. In fact, studios increasingly are being shared by two people, expanding the total occupancy of the building from 162 residents to approximately 250 in four years.

The students interviewed liked the idea of living in a sustainable building, yet they could not correctly identify Stephen Epler Hall’s green features. This is significant because the building’s efficiency is dependent on how it is used by its residents. For example, knowing to open and close windows in the living units and corridors at particular times of day makes an impact on the effectiveness of the natural ventilation system.

The design team intended for each occupant to receive information about the building’s sustainable features and how to manage them, but this practice was not implemented. And with the high turnover typical of college-housing residents, students have remained unaware of their living environment and do not use the building to its fullest potential. As for the overall design of the structure, the design team went beyond the original program and encouraged the client to add classrooms and office spaces on the ground floor to create a live/learn/work environment. This arrangement lent itself to a design strategy that includes a concrete base with five levels of wood frame above.

The concrete base provides the massing needed to cool the air brought in at the ground level before it is circulated up through the rest of the building. The addition of these types of spaces to the program worked well for the university in that it gained flexible classroom space, faculty offices and offices for The Northwest Science Expo, an organization that works with the greater Portland community. examines the project from start to finish. The term implies that the research and review not only discuss the end product, but also how the full planning and design process from schematic design to construction impacted the success of the project. Furthermore, the results of this type of POE provide lessons learned and inform planning for future projects.

Using interviews, surveys, photography and audio field recordings, the firm gathered information from the client group, design team, consultants, Placing public spaces at the ground level and private residences above also provides a layer of security for residents because the living units are not directly accessible from the ground. One drawback is that the air drawn into the building at the ground floor carries cigarette smoke from the adjacent plaza.

The classrooms are widely used by the campus community and are appreciated for being flexible and daylit, though many faculty members would prefer being closer to the academic core of campus. As part of the end-user interview criteria, subjects were questioned about PSU’s mission as it relates to their experience and knowledge of Stephen Epler Hall. Responses showed a strong sense of satisfaction in knowing the building represents PSU’s efforts to support Portland’s core sustainability values and provide students with a vibrant, urban educational experience. Based on the results of Mithun’s POE 360, a follow-up study similar to Turner’s 2005 study should be performed to determine how the increase in building occupancy and the high turnover rate of residents have influenced the building’s energy and water usage over time.

These results will inform whether changes need to be made to the building systems to accommodate increased demand. The results also will continue to inform the university and design team in future planning and design of sustainable student housing. Given the PSU community’s ongoing commitment to sustainable design, implementing an education package for new residents about their living environment will provide additional value.

LAURA CURRY is a cultural ecologist with Seattle-based Mithun. ELISABETH GOLDSTEIN is a planner and programmer for Mithun. STEVE MCDONALD is a senior associate at Mithun. RON VAN DER VEEN, principal with Mithun, is a senior designer who has created LEED-certifi ed buildings on more than 20 campuses and schools across the country. The authors can be reached at laurac@mithun.com, elisabethg@ mithun.com, stevem@mithun. com and ronv@mithun.com, respectively, or (206) 623-3344.