To limit the probability that the air leakage rate through the building envelope used as input in the energy model calculations will not be measured at a standardized test air pressure, which could lead to inaccuracy of the measured air leakage rate, which could lead to inaccuracy of the model, which could lead to overestimation of the energy used by the reference building or underestimation of the energy used by the proposed building, which could lead to excessive use of energy, which could lead to an unacceptable effect on the environment.