Stochastic versus deterministic approach to threshold criteria for Building/Environment system performance

Stochastic versus deterministic approach to threshold values as performance criteria for building/environment system is discussed in the paper. Methodology for specification of threshold characteristics as random variables is discussed. An example of calculation of the reliability of air exchange performance assuming first deterministic, and then stochastic performance criteria is carried out. The results obtained using these two approaches are analysed. The types of additional information that can be built in a model and its influence on performance evaluation are concluded.