Towards the Environmental Sustainability of the Construction Sector: Life Cycle Environmental Impacts of Buildings Retrofit

In the context of the need for carbon emissions reduction, the buildingsector, as one of the most energy intensive one, needs tools and approaches towards carbon neutrality and the increase of the buildings overall energy performances. The paper proposes an integrated approach towards the environmental performances analysis of a small neighborhood having as goal the achievement of the Positive Energy District target and the assessment of its environmental impacts. The methodology proposed includes building modeling and dynamic energy simulation using the Energy Plus engine and a simplified Life Cycle Assessment approach. Two scenarios are investigated: i) the existing neighborhood, ii) the redesigned one achieving Positive Energy District levels. Electricity use is computed in both scenarios, embodied impacts for the additionalmaterials and systems used are also computed in the second one. Results highlight significant improvements (up to 50%) in most environmental indicators, strengthening the need for holistic approaches when discussing the feasibility of carbon neutrality objectives, specifically when the general inclination is to choose just one indicator as metric.