WHAT is high-density complete community planning?

High-density, mixed-use, complete communities are defined by three key attributes: The first is their density. Although among planners there is no agreed-to definition of what qualifies as high density, the level of density much be that which provides enough dwelling units per hectare to support both a rich mix of retail and commercial at grade, and public transit such as at-grade or underground light rail transit. The second is the mix of uses both horizontally and vertically allowing for residential, commercial, retail, institutional and even some types of industrial uses to be mixed together to provide opportunities for inhabitants to live and work in close proximity. All of these uses are mutually re-enforcing, with high density residential occupancies providing the necessary population support a variety of retail and commercial activities at street level. The third is provision of planning for active transportation including both walking and biking, combined with an effective network of public transit.


High density, mixed-use, complete community planning is an essential ingredient to creating regenerative symbiotic cities. Planning and designing for dense mixed-use urban fabric not only reduces per capita green house gas emissions, but also reduces per capita resource use which in turn reduces the environmental footprint of cities and regional ecosystem degradation caused by low density suburban development.

Indeed, it has been demonstrated by physicist Geoffrey West that as cities grow in size and density their overall per capita metabolic rate (the rate at which a city consumes all resources including energy, water and material resources) decreases exponentially. What does this mean? It means that bigger cities are both more cost effective and greener!

Furthermore, consolidating the urban landscape through high density mixed-use planning is critical to getting people out of their cars and enabling the continued development of active transportation infrastructure and public transit. 

The suburban landscape, on the other hand is the antithesis of high density, mixed-use planning. Suburban development is now typically characterized by the strict segregation of land uses, consisting primarily of single family homes, strip malls, and fast food outlets. The lack of diversity, lack of proximity to essential services, and low density generates a forced state of auto-dependency, ensuring that walking, cycling and public transit is for the most part unfeasible. The average suburban household drives three times more than households in more urban settings. [source: Walter Siembab and Marlon Boarnet. Making Suburbs Sustainable. June, 2012] Not surprisingly, suburban sprawl is a major contributor to increased air and water pollution, greenhouse gas emissions, and the destruction of huge areas of natural ecosystems. In addition, living in the suburbs has been linked to a variety of social and health problems including obesity, heart disease, and asthma.

The consequences of suburban sprawl are pervasive and severe. Suburban land use systems are detrimental to cities due to their wasteful use of water, energy, land, and infrastructure resources. The Cost of Sprawl, a recent report by Sustainable Prosperity, demonstrates how the repercussions of sprawl affect the lives of urban and suburban dwellers alike. It reveals how unfunded infrastructure costs end up being subsidized by all taxpayers. These expenses include the construction and ongoing maintenance of new roads, sewers, water, and community centres, and ineffective public transportation. In North America, the development revenues collected by municipalities from suburban developers rarely balances the long-term life cycle infrastructure costs. For example, the City of Edmonton, in Canada has estimated that the costs to taxpayers for seventeen planned suburban developments will outpace property tax revenues by nearly $4 billion over the next 60 years. 

The Cost of Sprawl report demonstrates that the attractiveness of suburbs is driven by lower real estate prices. However, it has become increasingly clear that suburban development does not only not make long-term economic sense, it is bad for public health and environmental health. Climate change, air pollution, and the loss of natural ecosystems are some of the important negative externalities caused by suburban sprawl that rarely factor into financial calculations, but the consequences are real and lasting. Attempts to quantify these costs range upwards of $27 billion per year.[where?] Smog emissions in Toronto are estimated to cost the local economy $2.2 billion per year, and kill approximately 440 people per year. A symbiotic city, therefore, must acknowledge the need to redesign and repurpose the suburbs in a way that reconnects people to basic services, while also repairing the natural capital and the ecosystem services it generates.. 


Although the benefits of density are clear, many cities continue to under-invest in the necessary infrastructure for density, and have typically failed to develop coherent strategies to finance growth. Indeed, most cities around the world continue to sprawl outwards at low densities. Changing the current patterns of urban sprawl will be one of the greatest challenges, and opportunities of building the regenerative Symbiotic City. 

The mixed-use densification of cities is best facilitated within a regulatory environment which not only disincents the tremendous human and environmental costs caused by low-density urban sprawl, but rewards innovative design and efficient use of space and infrastructure.

Effective policy approaches for supporting and increasing mixed-use density in cities include:

1.    Property tax incentives that support density, including property taxes that are based on the size and use of municipal services of residences and businesses, rather than property value – which is both more equitable, and has property owners paying for what they need/use rather.

2.    User-pay tolls and fees for the use of roads, highways and bridges. This has the effect of incenting people to live closer to the city or where they work and driving fewer miles. User-pay tolls also reduce the tax burden of the inner city residents who are not using the roads and highways to commute.

3.    Planning and zoning policy that support and incent mixed-use and higher densities. This seems obvious, but in many cases, it is simply current policy that is in the way of positive change.

4.    Restricting the development of land development at the periphery of a city, forcing development and re-development to occur within the existing footprint of the city.

5.    Design of public spaces that increase the livability of cities to reinforce the positive features of dense cities.

6.    Effective urban design that supports and incents walkable, pedestrian friendly, human-scaled streets.


Changing the face of urban development patterns will require a new level of community engagement, framed in a real conversation about the necessary changes we will need to make to our urban environment if we are to transform cities into regenerative symbiotic cities. This conversation must recognize both the environmental and human health costs of current low-density development practices and the huge potential benefits associated with the development of high-density, mixed-use, walkable cities.



1.  On Streets, edited by Stanford Anderson

2.  The Economy of Cities, by Jane Jacobs

3.  Welcome To The Urban Revolution - How Cities Are Changing The World, by Jeb Brugmann

4.  Arrival City - The Final Migration and Our Next World, by Doug Saunders

5.  Triumph of the City, by Edward Glaeser

6.  Where Good Ideas Come From - The Natural History of In, by Steven Johnson

7.  Suburban Sprawl: Exposing Hidden Costs, Identifying Innovations. October, 2013;  www.thecostofsprawl.com/report/SP_SuburbanSprawl_Oct2013_opt.pdf

8.  Making Suburbs Sustainable; www.smartgrowth.org/nationalconversation/papers/Siembab_Boarnet_Making_Suburbs_Sustainable.pdf

9.  Landscape Architecture Foundation Case Studies; http://www.lafoundation.org/research/landscape-performance-series/case-studies/

10.  Greening the Suburbs: Exploring the Connections Between Suburban Development and Natural Processes. Genevieve Lodal. Spring 2008; http://www.amazon.ca/Greening-Suburbs-Connections-Development-Processes/dp/1243441518

11.  Designing Suburban Futures: New Models from Build a Better Burb. June Williamson;  http://islandpress.org/ip/books/book/islandpress/D/bo8654639.html

12.  Growing Sustainable Suburbs: An Incremental Strategy for Reconstructing Sprawl. Lucien Steil;  http://zeta.math.utsa.edu/~yxk833/suburbia.pdf

13.  Retrofitting Suburbia, Updated Edition: Urban Design Solutions for Redesigning Suburbs. Ellen Dunham-Jones; http://www.amazon.ca/Retrofitting-Suburbia-Updated-Edition-Redesigning/dp/0470934328