Design of compact residential blocks for sustainable urban regeneration: Determination of consistent qualitative criteria

Given the current ecological problems, it is nowadays necessary to reduce consumption. Demographic growth, economic growth patterns, lifestyles and consumption are leading to forms of unsustainable urban development, requiring ever-increasing resources in terms of land, materials and energy. This paper examines how architectural and urban research can help to mitigate this phenomenon while meeting the needs of the population. It is essential to examine the concept of reasonable density and compact urban typologies in order to develop our cities in a sustainable and positive way, thus limiting the misuse of natural spaces and preserving biodiversity in the face of territorial challenges. The question is, therefore, how to construct cities that comply with sufficiently strong criteria of compactness to reduce their consumption without undermining their attractiveness or quality of life. Design and planning tools are lacking in this area. The research on which this paper is based already enabled us to identify criteria that can be used for analytical purposes and to help design morphologies that satisfy the needs of integrated and objective compactness. These criteria could in the future facilitate the development, at infra-local level, of new compact urban groups, predominantly composed of housing, in accordance with a target density. Unfortunately, there are many, sometimes contradictory criteria of compactness, depending on the target scales and objectives. A compact project considering built-up and unbuilt areas makes it possible to reduce not only areas to be urbanised but also lost areas and the use of materials. Nevertheless, an exaggeration of the concept may result in the area devoted to housing being too small, a loss of luminosity and an increase in shadow effects, the disappearance of separate outside areas or a problem of accessibility. Accordingly, targeting urban compactness gives rise to a difficult choice between various quantitative and qualitative parameters.