Cost-optimal maintenance and renovation planning in multifamily buildings with annual budget constraints

In strategic planning, maintenance and renovation plans serve as an instrument for multiple objectives (e.g., to control degradation, sustain optimal building performance, reduce the costs of operations, and meet budget requirements, etc.). The lack of a proper long-term plan can lead to financial difficulties, especially in older buildings where the components are old and in need of extensive maintenance and renovation. These difficulties are complex and more pronounced in less-attractive markets where maintenance and renovation budgets are limited and socioeconomic issues are prevalent. In order to address the complexity of the problem and fully utilize the potential value in buildings, multiobjective analyses of maintenance and renovation plans need to be carried out together with proper life expectancy analyses. Current planning methods are not flexible or efficient enough to combine life expectancy analyses with multiobjective optimization processes. This paper presents a maintenance and renovation scheduling method that utilizes a modified deterioration function for life expectancy analyses and combines it with a service life-cycle cost analysis to facilitate multiobjective optimization processes. To demonstrate its application, the proposed method is used for maintenance and renovation planning for two identical buildings of different ages. To further demonstrate its economic benefits, the proposed method is used for planning under a restricting annual budget constraint and the results are compared to the results from a conventional method used by the managing company. The proposed planning method helps decision makers choose maintenance and renovation strategies in difficult market situations and/or under budget constraints.