Ecological footprint of the use and maintenance phase of buildings: Maintenance tasks and final results

According to numerous studies, approximately 90% of energy consumption in the life cycle of buildings occurs during the use and maintenance phase. The main aim of this study is to propose a method for the detailed calculation of costs and environmental impact corresponding to this phase, thus providing useful data for Facility Managers. The organization of the consumption of resources into three fundamental elements (manpower, materials, and machinery) enables the cost to be broken down and the Ecological Footprint [1] indicator (EF) to be applied. In previous advances of this research, the development of the model was focused on the utility consumption and cleaning tasks. On this occasion, the model is completed with the handling of maintenance tasks and a detailed assessment of the results, in which the factors that mark the cost and environmental impact are identified, as well as the specific moments of this phase in which peaks occur. In order to compare the costs and impacts produced each year, economic and environmental discount rates are used with respect to a baseline year. The methodology is applied to the case of a college hall of residence that houses up to 139 guests. The results show that cleaning tasks represent 6% of the annual EF and 63% of the annual cost, and maintenance 14% and 17%, respectively, thereby justifying the need for quantification. Finally, seven tasks are identified that together generate half of the EF and cost of cleaning, and nine other actions that incur more than a third of the annual cost and EF of maintenance.