You are a model of predictability. You come to your office every day of the week at 8 am sharp, never one minute late. You take no breaks until noon, when you instantly disappear from your building. At 2 pm you rematerialize in your office, where you work until 6 pm. You take weekends off, and perhaps some other holidays. While in the office, you sit perfectly still and have your computer switched on. The heat generated from your body and your computer are flat constants, and the only difference between you and a radiator is the odor that slowly builds up in the office while you are there. This is your life, day after day, kWh after kWh, pol after pol (the unit of air pollution).

Hardly flattering, but this is the assumption most building simulation software packages make about you. Your presence, your activities in your home or your office contribute to the heat load and affect the air quality in the building, so no serious simulation software could afford to ignore your presence. Building simulationists therefore represent you as the dummy described above.

Anyone alive would find it hard to recognize themselves in this computer model, and that’s where Jessen Page steps in. A PhD candidate at the Swiss Federal Institute of Technology, Jessen develops more accurate mathematical models of our behaviour in buildings that will one day replace deterministic ones.

Jessen was hired by the Solar Energy and Building Physics Laboratory (LESO-PB) in 2002, the same year he graduated from the University of Fribourg, Switzerland. Although his graduate work was in theoretical physics, he wanted to work on problems of sustainable development, and on solar energy—his lifelong interest since childhood—in particular. The LESO-PB was at that time involved in the SUNtool project, a new software package that would simulate the energy and materials flows of whole urban neighbourhoods.

The SUNtool developers did not want to use deterministic or profile-based behavioural models, and asked LESO-PB to develop behavioural models that would reproduce the most important characteristics with respect to the occupant’s impact on the building. Jessen’s doctoral thesis is about the use of so-called stochastic behavioural models, i.e. models whose state at time t is randomly determined.

Jessen’s work will introduce more realism in building simulation programs and help them make better predictions of urban energy demands and flows of materials. Surprisingly, Jessen says that the impetus behind his work came not from practitioners or architects but more from academics.

I am therefore particularly pleased to be the first to announce on the Web that Jessen Page has succesfully defended his PhD thesis last August in front of a private jury, and will give his public defense shortly.