by Rick Pruetz, Vice President, Ecocity Builders
In the May issue of Ecocities Emerging, I wrote that compact urban form, by itself, can cut resource and energy use in half. Three other levers can likewise reduce resource consumption by 50 percent each. According to The Weight of Cities: Resource Requirements for Future Urbanization, a report from the International Resource Panel (IRP) for the United Nations Environment Program, when these four levers are employed in an integrated, mutually reinforcing manner, they can decrease resource use by 80 to 90 percent when compared with the resource consumption levels associated with current business-as-usual (BAU) practices (IRP 2018).
Focusing exclusively on the first lever, compact urban form, the post entitled Ecocities and the Power of Greenspace in the May issue of Ecocities Emerging reviewed the effectiveness of using greenspace to curb urban sprawl. This post deals with the need for cities to accommodate population increases and grow up rather than out by promoting compact redevelopment within current urban footprints. Traditionally, this transformation has involved the redevelopment of abandoned or underutilized industrial areas, ports, railroad facilities, military bases and shipyards into vibrant, mixed-use neighborhoods that rely primarily on ecomobility. More recently, the conversion of surplus shopping centers has also been seen a good way of creating livable, mixed use centers even in suburban areas.
All of the winners of the European Green Capital award offer good examples of planet-friendly redevelopment. But the Hammarby Sjostad project in Stockholm seems particularly appropriate to describe here since it is an ecocity fractal that incorporates all four levers described by the IRP in The Weight of Cities.
- Lever One: Hammarby forms compact urban growth by remediating a brownfield site in the heart of Stockholm and creating a transit-oriented, mixed-use community with a projected density of 15,000 people and 7,500 jobs per square km where many opportunities for work, education, culture, recreational and nature are close enough to be reached on foot or by bicycle.
- Lever Two: Hammarby uses traditional, inner-city, small-block design with four- to five-story buildings arranged to take maximum advantage of water features, walkways and open space.
- Lever Three: Hammarby minimizes consumption of energy and other resources by using closed loop technologies, many of which have been developed or improved for this project. For example, 11,000 apartments here are served by district heating and cooling that partly uses energy extracted from treated wastewater and solid waste combustion, which is also used to generate electricity. The advanced wastewater treatment system creates a biogas that powers many Hammarby stoves and ranges as well as buses.
- Lever Four: Residents of Hammarby are encouraged to practice planet-friendly behaviors including reliance on ecomobilty which is used by 80 percent of this neighborhood’s inhabitants (IRP 2018; Pruetz 2016).
Importantly, open space and water features are woven into every Hammarby neighborhood in ways that are functional as well as aesthetic. Storm water is partially retained by green roofs which feed into canals that are landscaped to treat pollutants. As a result, this ecocity fractal has become an economic development tool for Stockholm, attracting 10,000 visitors annually and creating an international clientele for the planners, architects, contractors and technicians that use Hammarby as their laboratory (Pruetz 2016).
IRP (International Resource Panel). 2018. The Weight of Cities: Resource Requirements of Future Cities. Paris: United Nations Environment Programme.
Pruetz, R. 2016. Ecocity Snapshots: Learning from Europe’s Greenest Places.
Hermosa Beach: Arje Press.