Vertical greening for public buildings retrofitting and urban carbon neutrality: A nature-based solution and design practice in China

In the context of massive urbanization and growing public demand for sustainable development, the new concept of eco-city regeneration has been arsing increasing attention in developing countries like. However, unlike new constructions, due to the existing buildings and spaces limitations, traditional greening design methods are often not feasible to meet the old renovation requirements for eco-city regeneration and low carbon urbanization. Therefore, this paper proposes an innovative vertical greening design solution to renovate old public buildings. As a typical illustrative example, a public market in Chengdu, China, was retrofitted with a full vertical green curtain wall, to find a natural based solution to current problems such as outdated facilities, poor ventilation and facade fading according to the field investigation and site survey. In this design roadshow, regional analysis, practical renovation strategy and carbon emission evaluation are conducted, with local wood and green plants selected as alternative ecological materials for eco-renewal. Preliminary design results show that by increasing the original 20 % green coverage ratio to 47 %, such low-rise public buildings can be revitalized and coexist harmoniously with the surrounding environment. Life cycle carbon indicators show that after the renovation of low-carbon old public buildings, the carbon emissions can be significantly reduced by about 19.7 tCO₂. Among them, building material production, construction and demolition stages are the main sources of building carbon emissions. This study provides new perspectives for modern green design concepts and management of traditional old buildings renovation, and offers novel application prototype reference for eco city regeneration in developing world.