Missing Pieces of the Urban Puzzle

The start of 2012 in Cape Town has seen a huge focus on urban and design issues; Design Indaba, Future Cape Town, the Cape Town Partnership, Modila Trust, Portside, 22 on Bree, Convention Centre Phase II and the City of Cape Town tenders for urban renewal nodes in Kapteinsklip and Athlone Power Station have all raised the urban profile significantly (and politically).

As might be expected, urban design issues have played their role in this discourse - density, mobility, urban renewal etc; but from my perspective, there are some significant pieces of the puzzle missing in planning for future cities.

On the face of it, the new urbanists seem to have it all sorted out: go to war on urban sprawl, shopping malls and car-based transport... Densify, invest in functional public transport and cycle ways, commit to pedestrianised urban malls and build good public space.

The urban design community seem to be well across this in terms of the design interventions and priorities for new urban spaces. Development corridors, mixed use ratios, thresholds at which public transport becomes viable and amenities for urban living are all well covered and we see them coming out in some of the world's leading cities. Architects have even started talking about context at the urban scale, which is a sure indication, of changing attitudes...

But we have absolutely no clue of how to quantify in design terms, and therefore design for, two key elements of urban spaces:

1. Our infrastructure requirements are only considered in terms of peak demand - we have no culture of quantifying the resource consumption and waste stream implications of urban design decisions; and

2. Our understanding of critical mass and nature of green space required for effective ecosystem health, biodiversity and ecosystem services is woefully inadequate.

What this means is that in terms of the key environmental factors of sustainability, our urban designers are effectively flying blind. When faced with some of the excellent work on resilience coming out of Sweden like the Nine Planetary Boundaries concept, we don't have the design tools for quantifying our cities' performance in resource or ecological terms.

And so we revert back to the building scale, and limit our focus on sustainability to demand mitigation at the building level. And this is the place many of our leading urbanists are stuck.

One of the benefits of urban-scale ecology and resource intensity models are that they provide a tool for facilitating integrated urban design, much like the detailed building simulation tools of thermal and daylight modelling did for architects and building engineers. This then opens the door for the design of integrated, decentralised urban infrastructure, which in turn unlocks the potential for nested systems to optimise the use of waste streams. And therein lies one of the secrets to getting our cities functional at a resources level as well as at an interactive level.

Even those of us with a passion for cities must acknowledge that we don't have a clear picture of what our cities should look like in a severely resource-constrained world. Energy, food security, supply chain and water issues are typically put into the 'too hard' box because they rely on such far flung, complex systems for their integrity. Our only response seems to be 'reduce demand for resources', yet with no evidence for this actually happening.

The first step to building smart cities must be providing urban designers with the critical performance models that allow design to be directed by resource limitations as well as social outcomes. Once we understand city morphology in resource and ecological terms as well as urban terms, we will be a big step closer to the sustainable cities of our imagination.