Economic evaluation of building energy retrofits: A fuzzy based approach

As a solution, this paper proposes a novel LCCA approach for building energy retrofits. The proposed approach calculates life cycle cost (LCC) by adopting fuzzy set theory. In order to illustrate the proposed methodology, a case study was conducted for a public building operated in the Okanagan region of British Columbia, Canada. Two energy retrofit alternatives − a major retrofit and a deep retrofit − were compared using the proposed fuzzy set theory-based approach and the traditional deterministic LCCA approach. Even though the deterministic result had a strong membership to the fuzzy membership function of the LCC, the range of possible LCC is wide. Use of the fuzzy-based approach would enable the forecasting of possible future LCC as a result of changes in macro-economic factors. This information would allow building managers to plan for adverse future scenarios.