sustainable urban design

No matter how much effort goes into trying to get people to understand the importance of sustainable development, cities aren't going to become more sustainable places until developers, their consultants, and planning authorities get on board. Even if the business case is made (and it has been made time and again*), that won't guarantee that things will change. And with growing political pressure to reduce carbon emissions, there still won't be change in the right direction unless there are guidelines and standards in place to point the way.

So I was excited to see a new edition of the UK Urban Design Compendium that now incorporates sustainability. It includes an explanation of urban design principles, over 100 case studies to show how they can be applied, and practical guidance on the steps that can be taken and barriers that need to be overcome during policy and project development to improve the quality of place delivered.

*The US Business Council for Sustainable Development has tons of information, and here's a report from SustainAbility specifically geared to the business case for sustainability in emerging markets.

a tall story

When "sustainable building design" was the only kind there was: 14-storey mud brick skyscrapers densely packed into the city of Shibam, Yemen. Still standing after two millennia.

incremental infrastructure

On a tour of Philippi railway station in Cape Town last week, architect Mokena Makeka explained how a new bridge over the railway line has been designed as an elevated street. More than just a utilitarian structure linking the station on one side with the Kosovo* squatter camp on the other, the bridge incorporates secure spaces for traders selling everything from food to clothes. One entrepreneur even had a sewing machine to make and repair clothes on the bridge. At midday on a Friday, the bridge was comfortably busy.

Down on the street, outside the ground-level station entrance, the amaRastas were selling fruit and vegetables, other vendors were selling a variety of sweets and small items, butchers were selling meat, and others were cooking and selling lunch at braai stands. More informal businesses lined Ingulufe Street on the approach to the station - some operating from homes, others in converted shipping containers, and still others under makeshift shelter or out in the open.

Many of these businesses appeared to be thriving, but there was a building next to the station providing rented space for small businesses, and only a few of the rolldown doors were open. It wasn't clear whether the others were vacant, or only operating during busy commuter periods, but the contrast of this underutilised building with the thriving informal businesses a few metres away highlighted the difficulties faced by planners trying to support the informal economy by providing infrastructure.

One of the biggest challenges lies in the need to provide a means for entry-level informal businesses to grow into something bigger. Many other stations across Cape Town and South Africa face the same situation, and there is no clear model in place for giving these street hawkers a leg up the economic ladder. So I was interested to come across Ethan Zuckerman's post [via Global Voices] about incremental infrastructure. He talks of regulating intelligently to provide an environment that allows for "self-provisioning":

...where you’re building a network to meet your own needs because no one else has built that infrastructure. Where self-provisioning meets incremental infrastructure, I think, is where you overbuild for your personal needs with the goal of selling that capacity to your neighbors... A farmer investing in water pumping equipment that could irrigate both his fields and neighboring fields might be builting pico-level incremental infrastructure, while a mobile phone company that built power plants to provide energy to mobile phone base stations, and used excess capacity to run irrigation pumps might be working on a micro or mini scale.

An example of self-provisioning in the housing sector that is widespread throughout South Africa, in both low-income formal housing settlements and in squatter areas, is the building of shacks or other structures in backyards to provide rental income. In many cases this is illegal, and in squatter settlements it is clearly completely unregulated, but nevertheless appears to be a significant part of the hidden economy. Government-provided low-cost housing often prevents this activity by positioning houses on plots in a way that renders the unbuilt space completely unusable.

Another possibility is in energy supply. Some squatter camps illegally tap electricity from the national grid, with cables running on the ground and propped in the air with Heath Robinson contraptions. While this is patently dangerous, using paraffin for cooking and lighting in shacks made of plastic, cardboard and wood is no better. If government provided the means for legal installation of solar electricity systems and local distribution networks, this would be a perfect opportunity for self-provisioning. Some residents could install a system and sell electricity to their neighbours. And there is a way to address solar affordability.

*Kosovo is one of Cape Town's most unfortunate squatter settlements. In 2005 the camp burned to the ground, and the area is frequently subjected to flooding. Improvement of the area with better social facilities and integration with the transport system is a high priority for government planners.

it's not going to be easy

Dongtan is not the only planned sustainable urban area planned for China. Another one is the village of Huangbaiyu, but this one is puzzling. The rendering of the original scheme shows an interesting concept, but this photo of built houses makes it look more like a standard subdivision. Some aspects of the design may indeed reduce ecological impact, but it's no model development.

The real question though, is why existing villagers are being asked to abandon their existing houses to move into new "sustainable" ones. The linked article points out that the existing villagers live scattered among their agricultural fields. Conventional wisdom may suggest that such low densities are bad as an urban model, but I would have thought that there is some wisdom in living where you work. Improving efficiencies by corralling the villagers and knocking down functional houses will only alienate them from the land. If this approach is more efficient, it is only because the fields will be consolidated and farmed by a bigger enterprise, and the villagers will have to start travelling to jobs elsewhere.

Maybe the mistakes with this village are just a bad pixel on a widescreen TV - though the villagers may have a different view - as the general approach sounds positive.

Update on 30 July 2007: I've just discovered another plan for a zero-carbon, zero-waste city, this one in Abu Dhabi. There's a curious rendering of a "solar tree" something like the fake trees that double as relay stations for cellular networks in South Africa, but this one has solar panels.

plan approvals process may tighten in California

Facing lawsuits challenging Environmental Impact Reports that don't assess the effects on global warming of particular projects, California is under pressure to consider climate change in decisions on land use, transportation, energy production and other projects requiring approval from public planning agencies. New land use policy may soon require, for example, that additional carbon emissions resulting from an energy-inefficient housing project or a car-based commercial development be quantified and considered in the approval process.

I wrote in November 2004 about Western Australia's updated neighbourhoood planning policy that encouraged lot design to allow for climate-responsive dwellings as part of a strategy to reduce energy consumption. The Californian and Western Australian examples are coming at the issue from different angles, and it would be interesting to see whether the two approaches could form components of one strategy.

Bostonians do it bigger

On the topic of Boston, the city seems to be working hard at reclaiming lost space. The Big Dig is moving an elevated highway underground, releasing prime downtown land for the Rose Kennedy Greenway and restoring the connection of the city with the waterfront. The Massachusetts Turnpike Authority provides images, plans and descriptions of how the greenway transformation will be done - while removing the highway frees up 30 acres, the total project will create more than 300 acres of landscaped and restored open space, including over 45 parks and major public plazas. The old Central Artery isn't cleared away yet, but the last car drove the highway last weekend.

Whether the Big Dig was worth its $15 billion price tag is another story, but two spinoff projects provide some compensation. One is the Big Dig House that I mentioned in April. Here's another description of how the house reused material from the Central Artery in a way that could be replicated in other building projects. Small in scale, big in ideas.

The other project is reclamation of a 105-acre waste dump on Spectacle Island in Boston Harbor by covering it with 6 million tons of material from the Big Dig tunnelling, creating a new park complete with solar-powered visitor centre with exhibits and information on the island's history. And can the planners be faulted for installing a composting toilet atop an "80-foot-high mound of trash"? [via Metaboston]

urban jungle

While there are a number of good reasons to increase urban densities, this BBC News article serves as a reminder that even reduced sprawl carries risks. Underused spaces in the urban fabric are often the first to be used for infill programmes to increase density because they are the easiest to develop. But even if they are not the most attractive parts of a city, they may still offer benefits similar to better-protected green lungs, which are important for social and recreational activity, biodiversity, storing carbon, reducing urban heat build-up, and for managing stormwater.

Just another example showing that as urban challenges intensify, our planning responses need to be more sophisticated and able to weigh up the tradeoffs inherent in decisions about how we shape our cities. If we don't bring together the parks managers, the road designers, the urban planners and a host of other decision-makers, we'll never get this right.

the image of green

Atlantic Yards, Brooklyn (USA): an interesting case study of the need for an integrated approach to transport and land use planning. Locating this large development close to a major transit hub, earning it the title "transit-oriented development", does not make it sustainable. Some aspects of this proposed development sound good, but plans for a significant number of parking bays throw into question its green credentials. Other concerns that have been raised suggest that the developer may be cherry-picking the easiest green features and ignoring the bigger picture. Image is everything.

urban climate

It's been known for some time that urban areas create a heat island as the hard surfaces store more solar radiation than the vegetation they replace. Adding to the effect is the heat generated from within buildings, and changes in air circulation. Studies have suggested that the result is significant enough to change the growth cycles of plants in some cities by altering the growing season.

Now scientists studying climate in areas of rapid urbanisation in China are finding changes in rainfall linked to urban sprawl. They speculate that an observed decrease in rainfall may be related to loss of vegetation, and the fast rate at which water runs off city streets, reducing the transfer of water to the atmosphere.

A lot can be done to mitigate urban energy waste, heat buildup and water runoff: from the layout of urban areas and the incorporation of vegetation, to the design of buildings and their heating and cooling systems. Strategies should include not only consideration of the way buildings are designed, built and operated, but also new approaches in disciplines like transport planning, traffic engineering, urban design and wastewater management. Some short-lived guidelines started to address these issues during the oil crisis of the 1970s, but only in recent years have planning guidelines started to incorporate energy considerations again. There are examples in Australia and the US.

I have no doubt that Dongtan Eco-city and its offspring will establish new standards for the planning of low-carbon cities, but until these initiatives become common practice, we'll have to rely on the examples set by individual buildings and small districts within cities. Here's a list (with pictures) of ten tall buildings that incorporate strategies to reduce carbon emissions and other environmental impacts.

house of the future

The house of the future will have elements from the past to reduce ecological footprints: rainwater collection, home gardens, underground cellars to keep fruit and vegetables cool, local delivery services, improved opportunities for walking and cycling, and shared community facilities.