This study proposes a combined life cycle assessment (LCA) and Geographical Information Systems (GIS) methodology to develop complex LCA inventories for multiple applications. The study focusses on the environmental implications of buildings retrofits, especially in the European context, where the building sector is one of the largest energy consumers. In this context, a new and holistic perspective is needed that expands from the building scale to the urban scale. The combination of LCA and GIS methods includes the development of an urban characterization model based on bottom-up methodologies. The environmental implications associated with increasing the thermal insulation of existing buildings to the current standard are determined based on LCA methods. In this step, common construction systems for building retrofits are used, and insulation materials are compared. Then, absolute and relative extrapolations are performed considering different urban morphologies. The results confirm the importance of the energy retrofitting of residential buildings in large functional urban areas such as the Barcelona metropolitan area, which is examined as a case study. The LCA results indicate that the selection of proper construction systems and thermal insulation materials is important to the environmental performance of building retrofits, and these selections can lead to CO 2 emission differences of up 16% in the region. The relative extrapolation results indicate significant environmental differences between urban morphologies. The LCA results show the potential strategic impacts of the inclusion of LCA methods in retrofit policies at the urban scale. *Revised Manuscript with No Changes Marked Click here to view linked References Highlights A bottom-up methodology is presented to measure and map the environmental implications of retrofit scenarios for residential buildings at the urban scale based on a combined LCA-GIS method. The study compares different construction systems and insulation materials, and significant differences are observed between retrofit scenarios. The method is applied to the Barcelona metropolitan area, Spain, considering the urban morphology as an aggregate method. The results show the potential strategic impacts of the inclusion of LCA approaches in retrofit policies at the urban scale.

Rives, J., The use of forest-based materials for the efficient energy of cities: environmental and economic implications of cork as insulation material.Sustainable Cities and Society

The COVID-19 crisis has changed daily habits and the time that people spend at home. It is expected that this change may have environmental implications because of buildings’ heating energy demand. This paper studies the energy and environmental implications, from a Life Cycle Assessment (LCA) approach, due to these new daily habits in residential buildings at their current level of thermal insulation, and in different scenarios of thermal retrofit of their envelope. This study has a building-to-building approach by using Geographical Information Systems (GIS) for the residential housing stock in the case of Barcelona, Spain. The results show that a change in daily habits derived from the pandemic can increase the heating energy consumption and carbon dioxide emission in residential buildings by 182%. Retrofitting all buildings of Barcelona, according to conventional energy renovation instead of nearly Zero Energy Buildings (nZEB), will produce between 2.25 × 107 and 2.57 × 107 tons of carbon dioxide. Retrofitting the building stock using energy recovery is the option with better energy and emission savings, but also is the option with higher payback time for buildings built until 2007. The methodology presented can be applied in any city with sufficient cadastral data, and is considered optimal in the European context, as it goes for calculating the heating energy consumption.

In light of the symptoms of obsolescence shown by housing estates built in the 1960-70s, numerous approaches have contributed to the debate on this urban form characteristic of functionalist urbanism. The study of open spaces-an aspect that, to a large extent, is responsible for the quality of housing estates-is still an ongoing research approach. However, fifty years after their construction, it is possible to see how its initial homogeneity has led to very different situations that are difficult to categorise. Only by addressing the specific urban processes that each housing estate has undergone will it be possible to promote conservation and regeneration strategies that are suitable for each case. This paper aims to develop a methodology that will help to offer a diagnosis of the urban quality of housing estates. The approach is based on urban morphology from a diachronic perspective, since the transformation processes are assessed from the initial situation to the present one. Through the basic elements that define the urban form the proposed methodology works with nine 'physical' variables. The specific analysis provided by the methodology helps in the definition of regeneration strategies for open spaces. The methodology was tested for three case studies in Spanish cities.

The retrofitting of less energy efficient building stock represents one of the most significant challenges in the transition to a low-carbon economy. Nowadays, the housing sector represents about 40% of the energy consumption in the European Union. In this regard, the level of insulation installed in buildings is directly related to the energy efficiency of the building, and consequently to the urban area. In addition, several studies have shown that a comprehensive perspective of energy efficiency is needed, together with calculating the importance of introducing Life Cycle Assessment (LCA) methodology. The purpose of this study is to develop a methodology to: first, measure the energy efficiency level of specific urban areas and their buildings using a geospatial model in an integral perspective; and second, the environmental impact caused by the refurbishment of these building façades using a LCA method.On the one hand, according to a bottom-up framework the quantitative and qualitative characterisation of the building stock façade at the urban scale is possible generating a georeferenced spatial data model of buildings using Geographic Information Systems. On the other hand, the environmental impact of the most usual constructive solutions to refurbishment building façades is calculated using the LCA methodology. The results obtained are merged and interpolated to the urban scale. The methodology is tested for the case study of blocks of flats in Barcelona using the open data of building stock from the Spanish Government. Firstly, this methodology provides more information in regard to urban areas as well as calculating their energy efficiency. Secondly, the study measures the renovation impact of the less efficient buildings. Finally, the results provide the basis for supporting decisions on building stock retrofitting for urban scale from a new approach, especially making the selection between various renovation scenarios much clearer.