Building Density

In urban areas, one way to organize urban development is to keep track of building density. The building density definition is a way to determine the concentration of buildings in a given geographic area. 

Why does Building Density Matter?

Higher building density patterns can have several effects upon the area analyzed. Whether it’s overcrowding, increased crime levels, increased traffic, and an increase in pollution, through careful planning of building density, a city can have an impact on these. In some towns, people feel in danger in crowded areas, while in others, knowing that the street is not deserted at 3 AM might be reassuring. It depends on the safety rating of each city, but building density can also impact it. 

Issues such as air rights and access rights assume great importance. Building density is also applied regarding the types of land uses. Finding the balance between industrial, commercial, and residential buildings is done through building density as well, while zoning ordinances will regulate property types on zones. Properties in high building density areas generally have greater values than the low-density areas because of the balance between supply and demand.

How is Building Density Used?

Building density’s most common way of measurement is the floor area ratio(FAR), limiting the size of the structure to the lot it is built upon. FAR covers the footprint of the building; however, it can’t control height. Because of that, there are high-rise buildings with a low-density footprint (skyscrapers) or low-rise buildings with a high-density footprint (malls).

The number of homes by land measure is a way that helps determine both building density and population density. It isn’t the most accurate one as the number of people doesn’t give us the number of households, nor does the number of buildings give us the size of the buildings.

What we do know is that tall buildings, skyscrapers, and the likes, while they increase the population density in an area, it doesn’t actually increase the building density of the area. Through high-rise buildings, the developers can maintain a low building density and supply the increasing demand for housing. The reason why high-rise buildings don't increase building density is because those buildings also need land around them. This is why New York has a lower building density than Paris, for example.