Holistically assessing building performance

As part of its 20-year sustainability strategy, UBC wants to see all residential and academic buildings on campus having a net positive impact on the environment and human well-being.

Achieving that ambitious goal will require a deeper understanding of how current buildings are performing — and that means developing better tools to assess a wide range of performance measures. To support this vision, UBC is developing a Green Building Plan for its Vancouver campus, which will govern sustainable development in all academic and residential buildings.

“One element being explored as part of UBC’s Green Building Plan is the use of post-occupancy evaluation studies to assess operating building performance and to inform the design of future projects,” explains Kerry Shaw, who was a student in the Master of Engineering Leadership (MEL) in Clean Energy Engineering program in 2017. “For my capstone project, I conducted a post-occupancy evaluation of UBC’s Alumni Centre as a pilot test to explore the logistics involved in completing such a study and to assess its usefulness as a tool.”

Post-occupancy evaluation (POE) studies are used to systematically and rigorously evaluate building performance and communicate project successes and failures. Typically, these studies combine energy and water consumption analysis with indoor environmental quality assessments to determine if actual performance is aligned with what was anticipated during the building’s design.

Kerry focused her study on the Robert H. Lee Alumni Centre. Completed in 2015, the Alumni Centre has attained gold-level LEED certification and includes social spaces, classrooms, high-tech meeting rooms and a café.

She reviewed two years of data and found that the actual energy use over the building’s operation was about 50 per cent higher than what was predicted. That difference is not surprising, she says, noting in her report that more than 50 per cent of LEED-certified buildings do not meet their energy and water use goals. Water consumption was significantly less than predicted – which led her to recommend that facilities staff confirm that all building water use is accurately being captured.

Kerry’s POE also incorporated other metrics beyond energy and water use, including a broad range of indoor environmental quality factors. She developed an online survey distributed to people who work in and use the building that asked them to reflect on 10 main topics, ranging from satisfaction with the social environment and building layout to thermal comfort and the building’s lighting and acoustics.

“These social environment elements are not typically included in POEs, but they are important for ensuring that UBC’s green building goals are met — including human well-being and placemaking,” she says.

The 41 people who responded to the survey were overall very satisfied with the building as a comfortable space to work and use.

“While the results of the POE in terms of energy and water metrics showed that the building isn’t performing the way it was predicted to, the occupant answers were overwhelmingly positive,” she says. “There is more going on in a building than how much energy it uses, and it is important to acknowledge the importance of how people feel in the space. People enjoy this building and being in it.”

Along with submitting a final report of her findings, Kerry presented the results of her POE study at a capstone conference, discussing both the results of this particular POE and its usefulness as a tool for better understanding a building’s environmental and social impacts. “My project mentors are interested in further exploring the use of POEs for future building projects on campus,” she says. “My project showed that POE is a viable tool for disseminating lessons learned from building projects, which will help inform the Green Building Plan’s development.”