Quick GIS-based tools for energy simulation, LCA and LCC analysis at the urban block scale. A cradle-to-cradle comparative methodology for evaluating energy refurbishment and demolition-reconstruction scenarios

The Italian residential building stock amounts to 12.2 million buildings, of which 7.2 million were built during the great expansion of real estate after the Second World War. These buildings were designed to respond to completely different housing needs when there were no specific regulations regarding seismic safety, fire resistance and energy efficiency, and are currently in an advanced state of obsolescence. Acting on this heritage becomes a key element toward the ecological transition, achieving 2050 climate neutrality targets. Nevertheless, there is no justification in cost/benefit terms for refurbishment operations due to the intrinsic criticalities of historic construction techniques. For this reason, this research proposes a replacement based on applying circular economy principles as one of the suitable intervention strategies. This paper presents a GIS-based bottom-up methodological approach to assess the life cycle impact of residential building blocks, including energy, environmental and economic aspects. Furthermore, this framework allows comparing several refurbishment scenarios with demolition and reconstruction in order to assess in a comparatively way the best solution for the case study, a residential urban block in Bologna, built in the first decades 1945-1965. The first tool gauges the building energy consumption for heating and cooling, employing the “Honeybee” plug-in; the second application aims to realise the Material Passport of the residential buildings, using the geometric data provided by the municipal georeferenced database and the constructive information sourced from archival research using “Grasshopper“ software. These tools allow LCA and LCC cradle-to-cradle simulation for the current state and the intervention scenarios, estimating the environmental impacts related to production, construction, use and end of life. In particular, the article Is focused on LCA by identifying solutions with the lowest environmental impact.