Uncertainty analysis and assembly aging can be meaningfully integrated into building envelope simulations to predict changes to heat and moisture transport when compared with typical non-probabilistic and nontime-dependent envelope analysis. A literature review of material durability, building envelope design for energy optimization, and longitudinal thermal performance is included to explore uncertainty analysis for building envelopes in current uses. Probabilistic inputs and time-varying material parameters are proposed as a method and tested on a typical wood-framed residential exterior wall through simulation. The results show that typical analysis underrepresents the risk of condensation in nearly all configurations when compared to probabilistic expected values. The location of additional insulation, using stochastic inputs and including degradation, can impact predicted condensation within envelope assemblies.
