Net Zero Carbon Building: un caso studio di metodo a Milano

The main cause of global warming is greenhouse gases emissions (GHG) and the construction sector is currently one of the main emitters of carbon dioxide, estimated around 38% of total emissions. To limit the rise in temperatures under 1,5°C, numerous scientific studies have shown that the most effective solution is reducing GHG to zero by 2050. In the construction sector, it has been proposed to reach the Net Zero Carbon Building (NZCB) goal, which is an overall balance of zero GHG during the life cycle of buildings, including both operational and embodied emissions, deriving mainly from the construction and disposal process. In Italy the current legislation provides that all new buildings are classified as nearly Zero Energy Buildings (nZEB) but does not place any constraints on embodied emissions. To undertake a path to reduce emissions, the first step is drafting an assessment of GHG along the life cycle of a building, through the calculation of the Whole Life Carbon Assessment (WLCA), as EN 15978:2011 indicated. The transition to an architecture built with bio-based materials is a key point to accommodate the pressing demand for new built volumes and the environmental issue, as well as retrofitting and reusing the built heritage are the main strategy for reducing embodied carbon and land consumption. These theoretical issues are applied in a case study focused on the redevelopment project for an abandoned office building located in via Ripamonti, Milan, to convert it into a research center by pursuing a strategy of carbon neutrality and reaching the NZCB goal. The circular economy’s principles, the reduction of embodied GHG, the reuse and retrofit techniques, such as volumetric addition and subtraction and recladding, combined with bioclimatic strategies and the use of biogenic materials have been the project design guidelines. The global design choices have been evaluated using a software for Life Cycle Assessment, One Click LCA.