To limit the probability that an inaccurate solar heat gain coefficient will be used as input in the energy model calculations for building envelope components and assemblies separating unconditioned interior spaces from conditioned spaces, 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.