Most studies in environmental psychology in general, and on children's behaviour in relation to their physical environment in particular are short-term in character. In most cases one environment is studied or several different ones are compared at only one point in time. Longitudinal research is rare, mostly due to restrictions in money, time and long-term perspective. But in order to evaluate the effects of physical transitions in environments, information about the 'normal' fluctuations in behaviourof its users is necessary as a frame of reference.