The influence of material selection on building climate neutrality: a case study of VELUX lab in Milan

Abstract

Concerns and interest regarding global warming have been growing in last decades and important countermeasures are being implemented. The construction sector is responsible for a significant amount of greenhouse gas emissions, therefore the role of sustainable construction should gain influence and provide guidelines for future new constructions as weil as refurbishments.

The trend is moving towards high-efficiency buildings, where the operations account just for a small percentage of the total impact. This is exactly the case of VELUX lab, which is the case study of this project. In particular the latter benefits from great operational performances. Nevertheless the high embodied greenhouse gas emissions classify the building as being high­impacting, therefore non-climate neutral.

The aim of this project is to investigate the influence of material selection on building climate neutrality, thus demonstrating to practitioners the benefits of using bio-based material on the global warming impact. In particular the strategy of storing carbon in bio-based construction products is exploited and different combinations of these products are assessed in so-called material diets. The approaches adopted to assess the life cycle of these combinations are four and in specific two of them consider the temporal distribution of the greenhouse gas emissions, namely the semi-static approach and the dynamic one. The latter are influenced by the storage period and the return period of bio-based material. In specific the assumed variables are 25 and 60 years for the first one and for slow-growing bio-based material the second one is 60 and 90 years.

The results show that climate neutrality can be obtain for different combinations. Anyway the effort required varies depending on the materials used. In particular especially the amount of aluminium, steel and concrete should be kept as low as possible.