Palme, Massimo

Technological imagination and innovation processes have always been at the basis of economic growth and the expansion of human domination over other species. Nevertheless, something seems to have got stuck. Can the leaps in technological development that make it possible to “reset” the clock to start growing again in a sustained form really be infinite? Or are we facing something different, a limit in the structural stability of the ecosystem itself? The worsening of the polycrisis – certainly also energetic – will require drastic solutions but should also finally allow the (re)emergence of radical ideas of renewal and transformation, as well as concrete proposals for spatial organisation associated with the new lifestyles they prefigure.

Urban heat island effect often produces an increase of overheating sensation inside of buildings. To evacuate this heat, the current use of air conditioning increases the energy consumption of buildings. As a good alternative, natural ventilation is one of the best strategies to obtain indoor comfort conditions, even in summer season, if buildings and urban designs are appropriated. In this work, the overheating risk of a small house is evaluated in four South American cities: Guayaquil, Lima, Antofagasta and Valparaíso, with and without considering the UHI effect. Then, natural ventilation is assessed in order to understand the capability of this passive strategy to assure comfort inside the house. Results show that an important portion of the indoor heat can be evacuated, however the temperature rising (especially during the night) due to UHI can generate a saturation effect if appropriate technical solutions, like the increase in the air speed that can be obtained with good urban design, are not considered.

Technological imagination has been, until now, a stronger driver of development and has permitted to scale economy and even to obtain increasing returns of investments. However, times are a changing. Humanity faces now societal and environmental changes that are pushing the planet Earth toward a danger zone, overpassing recommended limits for several critical processes, such as bio-geochemical fluxes of nitrogen and phosphorus, greenhouse gases concentration in the atmosphere, biodiversity loss and land use change. The role of technology applied to built environment design should be redefined to stay within the so-called safe operation space for humanity, considering the limited resources we have and the need of low-energy solutions for buildings and cities. This chapter introduces the key concepts for the understanding the new role that we must assign to technological imagination to face the challenge of the Anthropocene epoch and discusses how to achieve the seven transitions objectives for transforming our world in a sustainable way.

Global warming affects the built environment by changing the environmental conditions under which buildings operate. This change probably means a shift in thermal demand, from a predominant demand for heating to a higher demand for cooling in many climates. For instance, in cold climates global warming seems to be a self-decreasing phenomenon because of lower energy demand in warmer environments. In warmer climates, like the Mediterranean, and in the hottest climates (both humid and arid), global warming must be regarded as one of the main factors (the others are the change in comfort standards and the heat-island effect) in increasing the energy demand to cool buildings. This chapter analyses the environment of various cities, characterised by mild average temperatures and small thermal oscillations, that can be regarded as Mediterranean climate emplacements. Today these cities have more heating than cooling demand but in the future will probably have higher cooling requirements. Results show that by 2050, in most of the considered emplacements, cooling demand will be higher than heating demand and emissions will rise proportionally. Solutions to this problem must be sought in the flexible operation of buildings, and policies should focus on summer-related issues: good natural ventilation, protection from the sun, and internal gain reduction, rather than insulation, air infiltration reduction and solar access.