Scientists study the post-occupancy performance of green buildings

Dr. Guy Newsham had good news and bad news for attendees of the most recent Better Buildings Breakfast: The Occupants’ Experience of Green Buildings.
“Are green buildings as green as we thought? Well, the answer is they’re doing pretty well … “ said Dr. Guy Newsham, principal research officer for NRC – Construction said at a Better Buildings Breakfast held in Ottawa on April 25th. “In many cases, they perform very well,” he added.
The bad news, Newsham said, is that there are still plenty of ways in which green building rating programs could be improved.
In a global first, a recently completed Canadian study conducted by scientists with the NRC examined the post-occupancy performance of green buildings.
A scientific approach to building research
The National Research Council study included a post-occupancy indoor environment and energy performance evaluation of 12 green and 12 conventional office buildings across Canada and the northern U.S. A total of 2,545 occupants completed an online questionnaire pertaining to environmental satisfaction, job satisfaction and organizational commitment, health and well-being, environmental attitudes, and commuting.
Dr. Newsham has a Ph.D. in Building Science from Cambridge University and joined NRC in 1990. Internationally acclaimed, he has produced over 100 scientific publications. The scientist has led and supported research projects on office space design, green building performance, lighting quality and control, sensor networks in buildings, demand-responsive buildings, office equipment energy use, and thermal comfort.
To collect data for the study NRC wheeled in an c3po-type machine in order to conduct on-site physical measurements at a sample of 974 workstations including: thermal conditions, air quality, acoustics, and lighting, workstation size, ceiling height, window access and shading, electric lighting system, and surface finishes.

Image from Dr. Newsham's presentation at the Better Buildings Breakfast
Their study confirmed that employees were generally in better moods, were more satisfied with their workspace and slept better in green buildings.
“They slept better at home, not at the office, I mean,” Newsham clarified. “Sleep is one component of general well-being. These are things that green building advocates have always said so it shouldn’t be a surprise to see those green building results come out, but it’s nice to confirm them with objective data. The specific mechanisms by which that happens we can’t say yet.”
Green building occupants asked about the size of their workspace
One of the findings in the study is that occupants of green buildings are more satisfied with the size of their workspace than those in conventional buildings. “They are just more satisfied with the size for whatever reason” Newsham said. “There is reason to believe that people who are in brighter environments, more open environments interpret that as being bigger even if it isn’t. There’s lots of research which has looked at how people interpret space, so that’s one possible mechanism, but we didn’t look at those mechanisms in detail,”
While the findings are encouraging, the NRC scientist said there are still plenty of ways in which green building rating systems could be improved. “Placing a greater focus on reducing airborne particulates and taking acoustics more seriously would be good,” he said.
Development of post-occupancy evaluation protocols and their integration into on-going certification systems were two improvements to green building rating Newsham said would be worth consideration.
The interdisciplinary design process used extensively in the development of green buildings is ‘working very well’ according to Newsham. The design methodology has become a part of industry practice regardless of whether a building owner is seeking green certification or not he observed.

Chart from the NRC study Post-occupancy Evaluation of Green Buildings
Building dashboards should tell a story
Sustainable development specialist Chris Jalkotzy who also presented at the Better Buildings Breakfast loves a good story, especially one with a memorable green ending.
“It’s not by accident that we tell most of our history through stories because we remember them,” Jalkotzy said. “We like books, we like movies, they have a beginning, they have an end, they have characters.”
“There’s a storyline and that is really, really important to us when we look at a building in the way it’s designed,’’ the Planning by People specialist continued.
Jalotzy raised the example of dashboards that have been installed in building lobbies to display real time information about the energy performance of buildings. They are intended to raise the awareness of building occupants and visitors about energy usage and the impact of conservation measures.
“If they present it as a storyboard and you can see that story in the dashboard, I think that dashboard will work” said Jalotzy, “currently, dashboards don’t work at all.”

Industry Events