Green maintenance for historic masonry buildings : a life cycle assessment approach

This research establishes the concept of ‘Green Maintenance’ modelling for historic masonry buildings. It recognises the important role of maintenance and repair in reducing embodied carbon expenditure, thus minimising the Environmental Maintenance Impact (EMI) typically associated with the deterioration of external stone masonry walls. The model was developed using a mathematical framework, and it generated results described in terms of EMI. This model utilises life-cycle assessment (LCA) ‘cradle-to-site’ over a selected maintenance period. The work evaluates embodied carbon expenditure from different stone masonry wall repair techniques for historic masonry buildings during their maintenance phase. It was discovered that embodied carbon expenditure for these repair techniques are highly influenced by the number of maintenance interventions, longevity of repairs, total wall surface repaired (m2), the embodied carbon coefficient value (‘cradle-to-gate’) and kg/km emission factors (‘gate-to-site’) associated with materials and repair processes. Based on the EMI in terms of embodied carbon expenditure generated from the results of ‘Green Maintenance’, the efficiency of stone masonry wall repair techniques can be determined. This not only aids in maintenance decisions making processes, but also contributes in substantiating the philosophical defensibility and sustainability of interventions. In the broader sense, this model is not simply confined to masonry and will be of use to those entrusted with the repair of other elements and components.