Measuring

The density atlas is a dynamic urban planning, design and development resource for students, professionals and citizens. It enables concise comparison of built project densities around the world. In conventional urban planning in the United States, the terms “high”, “medium” and “low” are often used to describe density. These terms are misleading not only because they typically take into account only one measure of density (where there are actually several factors that contribute to density), these terms also fail to account for the wider range of densities worldwide. Learn More

Scale

Another key element in measuring density is the use of appropriate scale. The measuring system used here compares developments on block, neighborhood and district scales. Comparing densities across different scales is not a fair assessment, as each scale has unique qualities that contribute to density. Learn More

Focus

The focus of the density atlas is case studies of projects and neighborhoods at “urban” densities, which generally range from FAR 1.0 – 7.0.

Each case study includes the following elements:

• Three density measurements
• FAR, which measures building bulk
• Dwelling Units per Acre/Hectare which measures the number of households
• Population per Acre/Hectare, which measures the impact on streets and services
• Basic project statistics, demographics and financial information
• Project narrative
• Aerials and plans, and other available images

Each case study includes a “Density Measurement Profile,” a concise summary of the three density measurements (further explained below).

In addition to the case studies, this site also provides background information on density measurements and perceptions, and serves as a growing repository of density resources (both print and web format).

 

The Density Measurement Profile allows viewers to quickly compare the density of the case studies. Using the three measures of FAR, dwelling units, and population – rather than a single measure – creates a more complete view of the density of a particular project. The use of the DP as a comparative tool is illustrated in the following four examples.

Density (specifically referring to the density of urban space) has numerous definitions and methods of measurement. When we talk about density, we may define it by how many people live in an area, the size of buildings on a given site (floor area ratio or FAR) or how many homes are in an area (dwelling unit density). The lack of a universal means of measurement creates some . In addition to the lack of a universal measurement, vague definitions are also commonly used, also creating confusion. "High, medium and low" degrees of density will vary significantly both in the way they are measured (FAR? Dwelling units?) and in the level of measurement (30 DUs per acre may be "high" in one context and "medium" or "low" in another).

Often when people talk about density, certain values are implied. The term "high" density may bring up images of efficient land use, diverse communities, and lively street life to some, or dirty streets, crime and poverty to others. The term "low" density may bring up images of home ownership, pastoral landscapes, and families to some, and sprawl, isolation and bland homogeneity to others. These values arise from perceptions about real places and become attached to certain agendas. None of these values is inherently related to actual density measurements, but it can be difficult to break free from existing perceptions. It is possible to have home ownership and families in "high" density areas, and efficient land use and diverse communities in "low" density developments. When planning, it is important to separate values and qualitative ideas about density from quantitative measurements of density.

Why Care?

2008 marks the point when the world population shifted from a majority of rural dwelling people to urban dwelling people. How we plan the places we live has become increasingly important, with this boom of new and growing cities and changing demographics. The planet has limited amounts of space and resources. We need to think carefully about how we use the space we have – whether for agricultural or commercial production, residential settlements, recreation, or conservation. Haphazard greenfield development destroys animal habitats and natural fields and forests, which are vital to the health of the planet. The costs of urban sprawl have been measured by many experts over the last half century. Infrastructure and public and private services costs are directly related to the density of a city, with costs generally rising as density lowers.

Additionally, sprawling development comes with hidden and indirect costs from loss of open and agricultural space, auto dependency, and urban blight from abandonment of central city cores.  It is clear that we need to use our resources wisely, and plan for livable cities offering a high quality of life. Higher density cities will help us conserve land for wilderness habitats, environmental protection and agriculture. But can they provide a high quality of life for their inhabitants? What does it mean to live in a high density neighborhood? The case studies and literature review found on this site will help us navigate through different levels of density and patterns of urban living to better understand how we can build in ways that are conducive to a high quality of life, while at the same time can work to protect and preserve our finite resources.

History

Perceptions of density can arise from historic imagery. Images of old tenement housing - highly dense configurations, poor quality units, insufficient access to light and air and poor sanitation conditions - may be linked to ideas about density, although quality of life factors, such as access to light and air, are independent of quantitative density measures. Many extreme dense cases are historical.

The evolution of buildings and settlements can be closely linked to societal mandates for access to light and air. Over time, building design has adapted to allow for compact residences, all with access to light and air.

[Sia's diagram here]

Culture

Cultural attitudes also play a significant role in density perception, as well as comfort with different levels of density. Studies of inhabitants of Hong Kong, one of the most densely settled places on earth, reveal a positive attitude about the current level of density. With an efficient transportation system, "borrowed spaces" such as cafes, which provide additional gathering spaces, and clean neighborhoods, and proximity to friends and relatives, higher density living can be quite pleasant.

[Insert image of multi generational family eating dinner or hanging out]

Values

Values are often attached to specific density levels, shaping one's perception of density. Because qualitative variables contribute strongly to one's perception of density, it is important to understand how these qualities contribute to the "feel" of a place in addition to understanding the real quantitative measures of urban density. Places that feel "dense" may  actually only feel that way due to certain qualitative issues, such as poor maintenance, the design and character of streets and sidewalks, or cultural perspective, while other places may feel less "dense" but are actually only configured differently.

Density alone does not have positive or negative attributes, however, many groups of people speak of it as it if has assigned values.  Some common arguments for and against density include:

FOR Density:

Dense settlements help conserve land.
Dense settlements are more energy efficient.
Density helps reduce driving and promote options for alternative transportation.
Density is supportive of social networks.
Density encourages diversity.

AGAINST Density:

Dense settlements are associated with increased crime.
Dense settlements are dirty and unhealthy.
Dense settlements are bad for social networks.
Dense settlements lack open spaces.
This atlas serves to showcase case studies and compare neighborhoods of varying density, allowing the viewer to make individual analysis.

[Insert image of multi generational family eating dinner or hanging out]

Design

Building design, site coverage, landscaping and other urban design elements also contribute greatly to one's perception of density, and also the comfort of the space. We have varying preferences about the types of space we live in, but there are universal constants that apply – availability of sunlight, some level of privacy, greenery, and cleanliness. The following diagram compares different configurations of buildings, based on FAR and building coverage. This illustrates the importance of using multiple measures to determine density, as there are many possible iterations of the same FAR using different degrees of site coverage. Some have preferences for high-rise buildings, allowing for large amounts of open space, and others may prefer mid-rise buildings, with more sectionalized open space. Each of these layouts may evoke different individual perceptions of density, although the FAR is constant.

Environmental cues can contribute to one's perceived measurement of density. Specific cues in the environment can alter perceptions of density. Evidence of human activity, such as trash, noise pollution, excessive motion can make an area feel more densely populated. At extremes, these can cause feelings of crowding due to the perceived notion of being "surrounded" by others with less respect for the shared space.

Crowding is typically viewed as a negative experience, although, in fact, crowding is only an intensifier of an experience. For example, crowding could be perceived as "good" at dance clubs or parties when surrounded by friends, but quite the opposite on a subway car at rush hour (especially on a hot day!). Crowding can be a very personal experience, stemming from cultural and social upbringing and personal attitudes.  According to a study by Amos Rapaport, crowding combines the interior and the exterior experience. The number of people living in a specific dwelling unit can greatly affect the feeling of crowding. Privacy is also a factor in crowding. People may feel comfortable in small units, as long as there is a strong separation from their interior private space and the outside world. The degree of homogeneity is also a factor in crowding. When people know, relate to and are comfortable with their neighbors, they tend to feel less crowded then when living in close proximity to people they don't know or with whom they feel uncomfortable.