Constructive strategies and environmental assessments towards temporariness, circularity and reversibility

Today architectural design is faced with the complex relationship between time and sustainability. In this perspective, the article reports the results of an articulated research activity, which highlights how the need for a temporary location or use of spaces can be achieved with an appropriate level of environmental sustainability, and only through longterm use of resources during the entire life cycle. The concept of "long-lasting temporariness" is outlined, based on the extension of the life of artefacts and on the reuse/recycling of resources at the end of their life, when the reversibility of construction systems, the circularity of materials, and the life cycle management of material and energy flows assume a paradigmatic role. Time-based design Relations between time and architecture, traditionally addressed with solutions characterised by permanence and long duration, are now subjected to new interpretations aimed at identifying effective answers to the widespread need to have spaces with limited functional duration or location time, thus underscoring solutions characterised by temporality. A two-fold tendency, which is at times ambiguous and contradictory, can be observed in this perspective. On the one hand there is an increase in requests and requirements related to the short duration, and on the other hand there is a growing need to direct design towards reducing energy consumption and resources, and environmental impact. The current needs about temporary use risk introducing the short-term consumer logics typical of industrial products used for periods of time typically less than 5 years into the construction sector. It implies a shortening of the useful lifespan of building parts, which are typically used for long periods of time, due to the accelerated functional obsolescence of spaces and building components. In order to solve this problem, project attention should ensure temporariness within a perspective of efficient use of resources, verifying the environmental effects through the entire life cycle. The life cycle approach and, specifically, LCA studies (Life Cycle Assessment) adopt an integrated and holistic view of the production processes, the origin of the building materials, the construction and implementation techniques, the maintenance operations and replacement, the methods of disposal and recycling of demoli