A ban on housing? Zero people to housing?

Housing is used worldwide to provide humans protection from the sun and the elements, to defend against wrongdoers, and a place in which to socialize and raise a family. Primeval forms of housing have been in use since ancient times. Primitive man used natural geological features for housing (i.e. caves, grottos), perhaps even choosing the position strategically. For example, dry caves were infinitely preferable to damp ones. Later in history, readily available materials such as mud and wood were widely used. More elaborate forms of housing were developed following the introduction of tools to work with more valuable and durable building materials such as stones. In times when societies were less civilized and did not tend to flock towards the city, housing was undoubtedly environmentally sustainable. However, following an increasingly concentrated urbanization, housing started to represent a considerable problem for the environment, polluting the air, land and waters. With the advent of the industrial society, the growing demand for housing linked to productive activities became extremely critical, environmental conditions deteriorated and space on which to build was less readily available. In modern times housing has evolved considerably from a technical point of view, placing greater emphasis on subsoil issues and relevant interrelationships. The use of innovative materials have, on the one hand, led to the development of safer housing, whilst on the other to a widespread diffusion of building techniques even in areas previously deemed unsuitable for the establishment of housing facilities. Housing complexes have been developed along the coastlines or on steep slopes, at times in an environmentally precarious position and at others constituting a blatant breach or even compromising the territory, the landscape, and safety. In numerous settings housing has often been built illegally, (i.e. in Southern Italy) with housing facilities being developed despite the lack of authorization, in areas of considerable environmental esteem or vulnerability (Fig. 1). Frequently, these forms of housing are supported by organized crime and have constituted a major form of livelihood. Extended forms of housing with large surface areas are widely applied in countrieswith a lower populationdensity,whilst in countries such as Japanhousing is strictly regulated, and planners are frequently forced to recover areas from the sea on which to build. Still today housing is widely applied in low income countries in conditions that are not acceptable from either an environmental point of view or with regard to hygienic conditions (Fig. 2). Particularly, housing which in no way corresponds to modern housing criteria, is frequently built in the suburbs of the capital cities of African, Asian or Latin American countries. Uncontrolled forms of housing may even be developed on wetlands or areas of considerable hydrological importance, such as seas and lagoons. However, the developing countries also make use of the more widely used construction techniques applied throughout the industrialized world. This type of housing however is often developed inappropriately, not taking into account the cultural differences, the varied climatic conditions and the unjustifiably high costs. Nowadays both steel and concrete are used liberally, even in areas in which the use of wood or bamboo would be better suited. Likewise in the industrialized world, as environmental awareness increases, more environmentally sustainable forms of development are being proposed, avoiding concentrated housing, paying greater attention to siting, landscaping and land-use, applying energy-saving techniques and focusing on the choice of materials to be used. To assess the medium and long-term behavior of housing, tools such as Environmental Impact Assessment and Life Cycle Assessment are increasingly applied. Throughout the industrialized world the renovation and recovery of old forms of housing are rapidly growing, often in conjunction with modern installations that allow an extended offer of housing. If the older