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The City as Ecosystem?

Eileen Keenan July 6, 2009
Cultural Sustainablity, Urban Research

The City as Ecosystem

Recently we’ve been looking much more closely at the work of those we like to call the system thinkers- the William McDonoughs, Michael Braungarts and Janine Benyus’s of the world. Their theories share the approach of modeling our solutions to the challenges posed by environmental degradation on those used by nature. Beyond ‘triple bottom line’ they propose approaches that are closed loop in strategy, eliminating non renewable energy input and waste creation. There is also an underlying theme that resources and energy are finite in quantity. At BTA we first started looking at this approach in our proposal for the 2010 Expo in Shanghai, where we established a set of guiding design values known as ‘The Shanghai Principles’ based on Cradle to Cradle strategies. This got us thinking more widely about the concept of cities or neighbourhoods as ecosystems. In nature no one individual species tries to ‘go it alone’- they all depend on other species for their food, shelter and energy needs. Why then do we aspire to our buildings becoming stand alone islands of self sufficiency? It this not contrary to the collective spirit that we claim is essential to solve our global environmental, social and economic challenges?

It seems to us that as with so many of our current issues what is required is a paradigm shift in how we frame the issue. Suppose that instead of looking for strategies to meet a projected ongoing increase in demand for resources such as energy, water and waste management that we simply started from the premise that all these resources are finite in capacity? Suppose we set limits for the amount of electricity that can be generated, potable water supplied and waste treated based on what our regional ecosystem can sustain without permanent and irreparable damage? Once we start to consider a resource such as electricity as finite, we can start looking at our demand issue as one of redistribution rather than increased supply.

So how might this work in practice? Lets say that in the future a developer wishes to build a project in Vancouver. Their first requirement would be to quantify the amount of electricity, gas, potable water and solid/liquid waste their development will generate. Their next step is to source the amount of resources they require from within the existing system. They do this by funding retrofits to existing building stock that generate savings equal to the resources they require. Meanwhile a parallel program has been developed that works with Strata corporations and low-income owners to undertake resources audits that identify the quantities of energy water and waste that could be saved by building upgrades. A central resources database is thereby established that identifies retrofit projects, costs and potential quantities of resources saved. The developer accesses this database and selects projects that singly or combined generate the resources required to allow their project to proceed. A commitment to fund these retrofits is required for a Permit to be issued. This could be phased in over a period of time, with developers initially only having to find eg. 25% of the resources they require, ramping up to a long-range target of 100%. The City could pass the associated long term savings generated by reductions in infrastructure projects in the form of reductions in other development charges.

A recent proposed project called Stable Flats in Philadelphia, by a design development collective called Onion Flats is based on similar principles. It proposes a very novel heating and cooling system based on building a 1.6million litre underground tank that will accept storm water from both the site and the larger community/ surrounding area. The development will then use that water as a heat exchanger to help heat and cool the building with a geoexchange system. An additional benefit is that they’re working to have this feature recognized as public infrastructure and have the City contribute to the cost of the tank. The economics of this project work because since 2006 the City of Philadelphia has required developers to absorb storm water on new developments rather than directing it to storm sewers. In November 2008 it began charging a fee to projects who could not meet this requirement, with the intention of using the money to fund community based storm water projects. This raises the potential of creating a storm water transfer system as an alternative to expensive sewer replacement projects. Already, new developments in drought impacted areas of California are being required to fund water efficiency retrofits in specific existing buildings that save the amount of water that the proposed development is calculated to require.

What this really represents is a cap and trade system that reaches far beyond the current carbon debate. By treating our region as an ecosystem of finite capacity we can facilitate new development and retrofit existing building stock without limiting the resources available to future generations.