Our intention is not to examine the broader notion of population density, but rather to focus on that of urban density, which raises a number of economic, ecological, and urban planning considerations.

The London-based International Institute for Environnement and Development and the American United Nations Population Fund have studied these questions as they relate to urban planning in very densely populated cities, based on examples drawn from Asian metropolises. Studies, reports, and videos can be found on the website they have dedicated to urban density: http://www.urbandensity.org

Defining Density

In France, the Urban Planning Agency for Metropolitan Caen (AUCAME, or Urbanisme de Caen Métropole) concludes that there are several ways to define density in urban habitats:

• construction density
• housing density
• real  density
• lived density

Source: AUCAME website.

Construction Density

Construction density can be measured as a function of square meters of constructed space—in other words, in terms of the land occupancy coefficient. It can also be measured in terms of dwellings per unit of measurement (usually the hectare). Determining the area that should be considered can prove tricky. Density can have different meanings depending on whether one is considering it at the level of the parcel, the block, or the neighborhood. Even so, two distinct types of residential density can be distinguished:

• net density, which is measured at the level of the [[definitions:o_p:parcel|parcel]] or the block.
• gross density, which takes into consideration areas used by public buildings (schools, town halls, etc.), public roads, green spaces, and so on. This measure does not allow for comparisons.

Housing Density

Housing density is the relationship between the number of dwellings and ground surface measured in hectares, minus public roads.  For example, on a lot where each dwelling has an area of 900 square meters, the housing density is 11 dwellings per hectare.

Real and Lived Density

The Parisian Urban Project (l’Atelier Parisien d’urbanisme) conducted a study of 227 informants to understand how inhabitants perceive habitat density.  The results were very interesting:

• The more they are surrounded by tall buildings, the more oppressive they find it, the more people tend to find density excessive.
• In old urban neighborhoods, with a tight social bonds but smaller buildings, people are inclined to see density as a source of wellbeing and intimacy, rather than finding it oppressive.
• Finally, if the neighborhood is busy and animated, people find density less disturbing. Conviviality is a positive factor, leading to less suffering in dense habitats.

Urban Density across the Globe

• 38% in 1975
• 47% in 2000
• 50% in 2008 = This is the year beginning in which the share of the earth’s inhabitants living in urban areas first exceeded 50% => see also urban growth and shrinking cities
• 54% in 2015
• 60% in 2030 (nearly five billion people)

Source: http://whc.unesco.org/en/tentativelists/5932/

File translated by Michael C. Behrent – Assistant Professor – Department of History – Appalachian State University – Boone, NC  28608