Influence of Degradation Service Life of Construction Materials on the Embodied Energy and the Energy Requirements of Buildings

The construction of buildings and their operation have extensive direct and indirect impacts on the environment during the life cycle. Designers and builders face a unique challenge in attempting to meet the requirements of either new and renovated facilities that provide accessibility and security but also offer a healthy and productive working environment whilst minimizing their environmental impact. Methods to evaluate the environmental sustainability of buildings and those to measure operational energy efficiency often do not take into account the decay in performance of building materials over time. Results of ongoing research conducted at the Politecnico di Milano, Dept. BEST, are presented on the influence of the degradation of construction materials and their service life on the energy performance over the building life cycle. Focus was made on determining the embodied energy (ISO 14040) of building construction practices and maintenance, and the energy requirement (ISO 13790) for both heating and cooling. Studies were conducted on two different types of building: a 16 storey tower and a single-unit dwelling. Six types of building envelope were considered: five typical Italian brick masonry walls and one light-weight solution. For each of these wall systems and building types, standard methods were used to calculate the embodied energy for the selected solutions and the energy requirements over a building service life of 60 years. Monte-Carlo simulation was used to take into account the degradation of the thermal insulation over time, and thus to determine if and how building type and building envelope technology were sensitive to this degradation.