To limit the application of the trade-off path.
This is to limit the probability that the thermal resistance or thermal transmittance of doors and access hatches will be unacceptably low or high, respectively, which could lead to inaccuracy of the trade-off model, which could lead to underestimation of the energy use attributed to the building envelope of the proposed building, which could lead to excessive thermal transfer through the building envelope, which could lead to excessive use of energy for heating and cooling, which could lead to an unacceptable effect on the environment.