Urban density is a concept used in urban planning, urban studies, and related fields to describe the intensity of people, jobs, housing units, total floor area of buildings, or some other measure of human occupation, activity, and development across a defined unit of area. In general terms, urban density describes the degree of concentration or compactness of people or development in a city. As such it is to be distinguished from other measures of population density. Urban density is considered an important factor in understanding how cities function. Research related to urban density occurs across diverse areas, including economics, health, innovation, psychology and geography as well as sustainability.
A 2019 meta-analysis of 180 studies on a vast number of economic outcomes of urban density concluded that urban density had net positive effects. However, there may be some regressive distributional effects.
Sustainability
It is commonly asserted that higher-density cities are more sustainable than low-density cities. This is because they reduce urban sprawl, minimize land use, and make services and infrastructure more efficient and accessible to residents. Much urban planning theory - particularly in North America, the UK, Australia, and New Zealand - has been developed premised on raising urban densities, such as New Urbanism, transit-oriented development, and smart growth. This assertion, however, remains a contested or challenged one.
The link between urban density and aspects of sustainability remains a contested area of planning theory.Jan Gehl, prominent Urban Designer and expert on sustainable urbanism, argues that low-density, dispersed cities are unsustainable as they are automobile dependent. NASA, for example, has established a direct correlation between urban density and air pollution.
Others, such as Randal O'Toole of the libertarian Cato Institute, point to how raising densities results in more expensive real estate, greater road congestion, and more localized air pollution.[citation needed] At a broader level, there is evidence to indicate a strong negative correlation between the total energy consumption of a city and its overall urban density, i.e. the lower the density, the more energy consumed. The location and urban setting where densification processes occur therefore need to be considered for sustainable densification.
Measurement
Urban density is a very specific measurement of the population of an urbanized area, excluding non-urban land-uses. Non-urban uses include regional open space, agriculture and water-bodies.
There are a variety of other ways of measuring the density of urban areas:
- Population density - the number of human persons per unit area
- Median density - a density metric which measures the density at which the average person lives. It is determined by ranking the census tracts by population density, and taking the density at which fifty percent of the population lives at a higher density and fifty percent lives at a lower density.
- Population-weighted density - a density metric which measures the density at which the average person lives. It is determined by calculating the standard density of each census tract, assigning each a weight equal to its share of the total population, and then adding the segments.
- Residential density - the number of dwelling units in any given area
- Floor area ratio - the total floor area of buildings divided by land area of the lot upon which the buildings are built
- Employment density - the number of jobs in any given area
- Gross density - any density figure for a given area of land that includes uses not necessarily directly relevant to the figure (usually roads and other transport infrastructure)
- Net density - a density figure for a given area of land that excludes land not directly related to the figure.
Impact
A 2019 meta-analysis of 180 studies on a vast number of economic outcomes of urban density concluded that urban density had net positive effects. However, there may be some regressive distributional effects.
A 2020 study concluded that urban density "boosts productivity and innovation, improves access to goods and services, reduces typical travel distances, encourages energy efficient construction and transport, and allows broader sharing of scarce urban amenities. However, density is also synonymous with crowding and makes living and moving in cities more costly."
See also
- Compact city
- List of cities proper by population density
- List of countries and dependencies by population density
- Smart growth
- Transportation planning
- Urban sprawl
- Urban vitality
- Verticalization
- Population-weighted density
References
- Hess, Paul (2014). "Density, Urban". Encyclopedia of Quality of Life and Well-Being Research. Dordrecht: Springer. pp. 1554–1557. ISBN 978-94-007-0753-5.
- Lehmann, Steffen (2019). "Density". The Wiley Blackwell Encyclopedia of Urban and Regional Studies: 1–9. doi:10.1002/9781118568446.eurs0074. ISBN 9781118568446.
- Ahlfeldt, Gabriel M.; Pietrostefani, Elisabetta (2019). "The economic effects of density: A synthesis". Journal of Urban Economics. 111: 93–107. doi:10.1016/j.jue.2019.04.006. hdl:10419/173020. S2CID 157491186.
- Lehmann, Steffen (2019). "Understanding the Benefits of Urban Density". Urban Regeneration: A Manifesto for transforming UK Cities in the Age of Climate Change. Springer International Publishing. pp. 79–107. ISBN 978-3-030-04711-5.
- Williams, Katie, Elizabeth Burton, and Mike Jenks. "Achieving the compact city through intensification: An acceptable option." The compact city: A sustainable urban form (1996): 83-96.
- Jones, Christopher (2014). "Spatial Distribution of U.S. Household Carbon Footprints Reveals Suburbanization Undermines Greenhouse Gas Benefits of Urban Population Density". Environmental Science and Technology. 48 (2): 895–902. Bibcode:2014EnST...48..895J. doi:10.1021/es4034364. PMID 24328208.
- Hansen, Kathryn (August 19, 2013). "NASA scientists relate urban population to air pollution". NASA's Earth Science News Team. Retrieved 2019-07-09.
- Newman, Peter; Jeffrey R. Kenworthy (1999). Sustainability and Cities: Overcoming Automobile Dependence. Island Press. ISBN 978-1-55963-660-5.
- Eggimann, Sven; Wagner, Michael; Ho, yoo Na; Züger, Mirjam; Schneider, Ute; Orehounig, Kristina (2021). "Geospatial simulation of urban neighbourhood densification potentials". Sustainable Cities and Society. 72 (103068): 103068. doi:10.1016/j.scs.2021.103068. hdl:20.500.11850/491075.
- Rowlands, D. W. (27 November 2017). "The way we calculate population density is wrong. Here's what we should do instead". Greater Greater Washington. Retrieved 27 April 2020.
- Ottensmann, John R. (1 Feb 2018). "On Population-Weighted Density". SSRN. doi:10.2139/ssrn.3119965. S2CID 202919206. Retrieved 27 April 2020.
Population-weighted density is the mean of the densities of subareas of a larger area weighted by the populations of those subareas.
{{cite journal}}: Cite journal requires|journal=(help) - Duranton, Gilles; Puga, Diego (2020). "The Economics of Urban Density". Journal of Economic Perspectives. 34 (3): 3–26. doi:10.1257/jep.34.3.3. ISSN 0895-3309.
Further reading
- Newman, P and Kenworthy, J (1999) Cities and Sustainability: Overcoming automobile dependence, Washington, D. C. : Island Press ISBN 1-55963-660-2
- Pont, Meta Y. Berghauser and Haupt, Per (2010) Spacematrix: Space, Density and Urban Form, NAi Publishers, ISBN 9789056627423
- Dovey, Kim and Pafka, Elek (2014) "The urban density assemblage: Modelling multiple measures" in Urban Design International, vol.19, nr. 1, pg.66-76
External links
- MIT Density Atlas
- Urban Density and Energy Consumption
Urban density is a concept used in urban planning urban studies and related fields to describe the intensity of people jobs housing units total floor area of buildings or some other measure of human occupation activity and development across a defined unit of area In general terms urban density describes the degree of concentration or compactness of people or development in a city As such it is to be distinguished from other measures of population density Urban density is considered an important factor in understanding how cities function Research related to urban density occurs across diverse areas including economics health innovation psychology and geography as well as sustainability A 2019 meta analysis of 180 studies on a vast number of economic outcomes of urban density concluded that urban density had net positive effects However there may be some regressive distributional effects SustainabilityA graph showing the relationship between urban density and petrol use It is commonly asserted that higher density cities are more sustainable than low density cities This is because they reduce urban sprawl minimize land use and make services and infrastructure more efficient and accessible to residents Much urban planning theory particularly in North America the UK Australia and New Zealand has been developed premised on raising urban densities such as New Urbanism transit oriented development and smart growth This assertion however remains a contested or challenged one The link between urban density and aspects of sustainability remains a contested area of planning theory Jan Gehl prominent Urban Designer and expert on sustainable urbanism argues that low density dispersed cities are unsustainable as they are automobile dependent NASA for example has established a direct correlation between urban density and air pollution Others such as Randal O Toole of the libertarian Cato Institute point to how raising densities results in more expensive real estate greater road congestion and more localized air pollution citation needed At a broader level there is evidence to indicate a strong negative correlation between the total energy consumption of a city and its overall urban density i e the lower the density the more energy consumed The location and urban setting where densification processes occur therefore need to be considered for sustainable densification MeasurementUrban density is a very specific measurement of the population of an urbanized area excluding non urban land uses Non urban uses include regional open space agriculture and water bodies There are a variety of other ways of measuring the density of urban areas Population density the number of human persons per unit area Median density a density metric which measures the density at which the average person lives It is determined by ranking the census tracts by population density and taking the density at which fifty percent of the population lives at a higher density and fifty percent lives at a lower density Population weighted density a density metric which measures the density at which the average person lives It is determined by calculating the standard density of each census tract assigning each a weight equal to its share of the total population and then adding the segments Residential density the number of dwelling units in any given area Floor area ratio the total floor area of buildings divided by land area of the lot upon which the buildings are built Employment density the number of jobs in any given area Gross density any density figure for a given area of land that includes uses not necessarily directly relevant to the figure usually roads and other transport infrastructure Net density a density figure for a given area of land that excludes land not directly related to the figure ImpactA 2019 meta analysis of 180 studies on a vast number of economic outcomes of urban density concluded that urban density had net positive effects However there may be some regressive distributional effects A 2020 study concluded that urban density boosts productivity and innovation improves access to goods and services reduces typical travel distances encourages energy efficient construction and transport and allows broader sharing of scarce urban amenities However density is also synonymous with crowding and makes living and moving in cities more costly See alsoCompact city List of cities proper by population density List of countries and dependencies by population density Smart growth Transportation planning Urban sprawl Urban vitality Verticalization Population weighted densityReferencesHess Paul 2014 Density Urban Encyclopedia of Quality of Life and Well Being Research Dordrecht Springer pp 1554 1557 ISBN 978 94 007 0753 5 Lehmann Steffen 2019 Density The Wiley Blackwell Encyclopedia of Urban and Regional Studies 1 9 doi 10 1002 9781118568446 eurs0074 ISBN 9781118568446 Ahlfeldt Gabriel M Pietrostefani Elisabetta 2019 The economic effects of density A synthesis Journal of Urban Economics 111 93 107 doi 10 1016 j jue 2019 04 006 hdl 10419 173020 S2CID 157491186 Lehmann Steffen 2019 Understanding the Benefits of Urban Density Urban Regeneration A Manifesto for transforming UK Cities in the Age of Climate Change Springer International Publishing pp 79 107 ISBN 978 3 030 04711 5 Williams Katie Elizabeth Burton and Mike Jenks Achieving the compact city through intensification An acceptable option The compact city A sustainable urban form 1996 83 96 Jones Christopher 2014 Spatial Distribution of U S Household Carbon Footprints Reveals Suburbanization Undermines Greenhouse Gas Benefits of Urban Population Density Environmental Science and Technology 48 2 895 902 Bibcode 2014EnST 48 895J doi 10 1021 es4034364 PMID 24328208 Hansen Kathryn August 19 2013 NASA scientists relate urban population to air pollution NASA s Earth Science News Team Retrieved 2019 07 09 Newman Peter Jeffrey R Kenworthy 1999 Sustainability and Cities Overcoming Automobile Dependence Island Press ISBN 978 1 55963 660 5 Eggimann Sven Wagner Michael Ho yoo Na Zuger Mirjam Schneider Ute Orehounig Kristina 2021 Geospatial simulation of urban neighbourhood densification potentials Sustainable Cities and Society 72 103068 103068 doi 10 1016 j scs 2021 103068 hdl 20 500 11850 491075 Rowlands D W 27 November 2017 The way we calculate population density is wrong Here s what we should do instead Greater Greater Washington Retrieved 27 April 2020 Ottensmann John R 1 Feb 2018 On Population Weighted Density SSRN doi 10 2139 ssrn 3119965 S2CID 202919206 Retrieved 27 April 2020 Population weighted density is the mean of the densities of subareas of a larger area weighted by the populations of those subareas a href wiki Template Cite journal title Template Cite journal cite journal a Cite journal requires journal help Duranton Gilles Puga Diego 2020 The Economics of Urban Density Journal of Economic Perspectives 34 3 3 26 doi 10 1257 jep 34 3 3 ISSN 0895 3309 Further readingNewman P and Kenworthy J 1999 Cities and Sustainability Overcoming automobile dependence Washington D C Island Press ISBN 1 55963 660 2 Pont Meta Y Berghauser and Haupt Per 2010 Spacematrix Space Density and Urban Form NAi Publishers ISBN 9789056627423 Dovey Kim and Pafka Elek 2014 The urban density assemblage Modelling multiple measures in Urban Design International vol 19 nr 1 pg 66 76External linksMIT Density Atlas Urban Density and Energy Consumption
