So the project's planners pulled people out the equation, and went instead with whole-home automation. “The reason for the robotics was that, to have an apples to apples comparison of performance data across the houses, you wanted the occupant effect on energy use to be identical,” says Patrick Hughes, director of the Building Technologies Research and Integration Center at ORNL. All of the homes' behaviors, from the timing of the fridge doors opening to the length of time the showers ran and the TVs were left on, were based on data profiles of the average American. Which means that the three robohouses operated in perfect unison. Though the model of refrigerator varied, the robotic arms that opened them were identical, and on the same schedule. And since no robot is capable of reliably transferring clothes from washers to dryers, a matching volume of towels were left in all of the machines, with a mister installed in the dryers, that would add the appropriate amount of moisture before each cycle began.