New research on how occupants inhabit energy-efficient buildings reveals behaviors designers don’t anticipate—and a slew of bloopers
Don’t touch that thermostat.
November 29, 2017
You’ve built your shiny new high-efficiency building with all the latest energy-saving features: smart thermostats, motion sensor-activated lights, floors designed to absorb heat during the day and release it at night.
But when you look at your building’s actual energy use, the savings are far less than anticipated. Why?
Well, maybe the building’s occupants are putting popsicles on the thermostats so they can force the heat to go higher. Or maybe they’re using a toy to continuously trigger the motion sensor lights, to keep them from turning off when they leave the room.
Bet you didn’t think of that.
Researchers at Washington State University have examined how occupant behavior in high-efficiency buildings affects energy use, asking open-ended questions in an effort to discover unanticipated behaviors. Professor Julia Day and her team conducted surveys and interviews with occupants of more than a dozen high-efficiency buildings, including homes and offices. The answers revealed a number of behaviors designers did not anticipate.
“What I find most surprising in these studies is that oftentimes it seems that the end-user needs were either neglected, ignored or just not really understood in the first place within the design process,” says Day, who teaches at the university’s School of Design and Construction.
Day’s results were recently published in the journal Energy Research and Social Science.
One of the buildings Day studied was a remote weather station, where scientists observed the weather 24 hours a day. As part of its energy conservation strategy, the building’s lights had no switches, only motion sensors. But the scientists wanted the lights off at night, so they could see out the windows to do their work. This meant they had to stay absolutely still for 15 to 20 minutes to get the sensors to turn the lights off. If someone wiggled or sneezed, it was back to the beginning.
“That makes it impossible to do our job,” one occupant complained.
Unhappiness with motion sensor lights was a common grievance. In one office, an occupant covered the sensors with paper because the constant on-off was causing headaches. In another, occupants complained that the lights would turn off too easily because the sensor was aimed at a corner. So they set up a toy drinking bird—one of those desktop doodads that dips into a glass of water and rises again like a pendulum—to keep the lights on all the time.
Discomfort with temperature was another theme. The temperature deemed reasonable by the smart thermostat is not always comfortable to the occupants. So occupants found ways to trick the thermostat. They held cold popsicles to the sensors. They taped a coin to a windowsill to reflect light at the thermostat, forcing the AC on. Residents of one house, built to be nearly energy independent, put a large shag carpet over the masonry floor that was meant to absorb and radiate solar heat. The reason? Their feet were cold.
«[The research] doesn’t surprise me,» says Dak Kopec, an architect with a PhD in environmental psychology who teaches at the University of Nevada in Las Vegas. «Sensors and automation are based on averages, and people are not averages.»
Some of the ways occupants modified the buildings energy-saving systems could not have easily been predicted. In one office building, a lawyer said he’d never turn off his computer overnight because his billable hours were so high he’d lose too much money waiting for the computer to start. Other complaints also had more to do with psychology than physical discomfort—occupants found that the image-distorting qualities of energy-saving patterned glass made them anxious, or that they were hesitant to adjust energy-saving window blinds because they didn’t want to bother their coworkers.
To Day, this research underscores the importance of exploring both the technical and “experiential” aspects of buildings.
“When it comes to buildings and technology, I think that sometimes the focus can get very numbers-based,” Day says. “This isn’t necessarily a bad thing—I think we need metrics to understand how our buildings are working. It is extremely important to gather baseline data, make adjustments based on conditions, and try to improve buildings based on those data. But I don’t think we can forget about the people in the building in the process.”
Poorly considered architecture and design can have serious effects on occupants that go beyond mere discomfort, Kopec says. These effects can include anger and frustration directed at others, isolation and even aggression.
Day and her co-author, William O’Brien of Carleton University in Ottawa, have several studies planned in the near future to look at similar issues, and are looking for additional funding and participants. She hopes the work can make designers more sensitive to building occupants’ needs and realities. This way, occupants won’t need to make as many tweaks.
“It doesn’t matter how well our buildings are ‘performing’ if the people in the buildings are miserable,” she says.