To more effectively combat climate change, it is past time that we rethink zoning – a pervasive regulatory instrument that affects every aspect of the built environment in cities around the world. Janna Levitt and Drew Adams explain.
Late last year we began a conversation on how architecture can better respond to climate change. This urgent question must be understood within the broader context of how our cities, neighbourhoods and buildings are created.
At a time when many leaders dither on climate action, cities are stepping up – and no wonder. According to C40 Cities, a climate action network of more than 90 major cities around the world that represent a quarter of the global economy, cities create more than 70 per cent of global CO2 emissions and will bear the brunt of their effects. In fact, 90 per cent of all urban areas are coastal, and most cities are already feeling the impacts of climate change.
While many cities embark on laudable signature initiatives to counteract these effects, too often zoning codes remain intact and permit status quo built form to continue. To more effectively combat climate change, it is past time that we rethink this pervasive regulatory instrument that affects every aspect of our built environment.
It is instructive to recall that zoning originated as a means for increasing people’s access to daylight and fresh air in urban environments, and for separating incompatible uses. Fundamentally, zoning was about human health and well-being through climate-tuned built form. Today, it’s become our cities’ DNA: with the change of a single sentence, new forms of urbanism can take hold – or be inhibited.
Recoding Communities for Change
Fadi Masoud, an assistant professor of landscape architecture and urbanism at the University of Toronto, has become a leading advocate for a more climate-attuned approach to zoning. He argues that modern zoning has become too fixated on regulating land use to predictable outcomes. As a result, the planning of neighbourhoods becomes static, as opposed to evolutionary and responsive.
This comes into sharp focus in Southeast Florida and Miami, where, until recently, areas increasingly vulnerable to flooding were still being zoned for intensification. Masoud and the MIT Urban Risk Lab have been working to create new spatial planning tools. They have developed a visualization platform which maps – in combination – flood risk, ground water, permeability, infrastructure, topography, geology and other factors alongside zoning to inform parametric adaptations which Masoud calls “flux-based.”
“As concerns over the environment propel us to imagine new, dynamic models of urbanization, contemporary ecological theory offers a foundation for rethinking the mechanisms of conventional land use planning,” Masoud argues.
These efforts deliver a beautifully simple message, delivered in poignant and informative visuals: the highest and best use for any parcel of land is contingent upon the climate vulnerabilities it faces. Due in part to this, zoning in Southeast Florida is now being reassessed – which in turn creates new problems. In Miami, many less threatened areas are experiencing “upzoning” initiatives to strategically increase density in less vulnerable zones. Development pressures are therefore shifting from the historically high value, and increasingly threatened, coastal waterfront to inland areas that are naturally buttressed against the effects of climate change.
This has meant that some of the city’s less affluent neighbourhoods are now experiencing displacement and what has been called “climate gentrification.” What this underscores is that climate action cannot be divorced from the social dimensions of sustainability and opportunities to make more equitable cities. As we preserve higher ground for added density, through tools like inclusionary zoning so, too, can we preserve it for those without means to escape the impacts of climate change.
Zoning, Form and Performance
By focusing on form-based parameters such as setbacks , height, build-to lines, lot coverage and so forth – zoning codes have played a significant role in shaping our urban environments. Looking forward, planners need to recalibrate these same factors to meet climatic and performative objectives related to orientation, exposure and the interaction between buildings and the public realm. As the impacts of climate change and extreme hot/cold days become more prevalent and acute, we must rethink universally accepted, “across-the-board” approaches: for instance, the idea that buildings should always prioritize unmitigated sunlight to street level may become outmoded in certain places – and even more important in others.
To this end, London City Hall by Foster + Partners presents a compelling argument for climate-driven design. Specifically, its landmark form emphasizes minimizing surface area while enabling self-shading of the structure to increase performance. Jeanne Gang’s Solar Carve Tower in New York takes similar formal inspiration from environmental determinants. While Foster and Gang provide clear examples of how designers can lead the way, environmental performance through built form can be codified with the same zeal they once were.
Reducing Restrictions – or Unzoning
The efficacy of zoning does not depend on the wholescale re-planning of our cities. Rather, by selectively removing certain restrictions on form and use, we unleash the potential for profound transformations. In the Globe and Mail, Alex Bozikovic comprehensively details the need to make way for the “missing middle” – a phenomenon affecting Toronto, Vancouver, Montreal and many other cities – and the constraints to this. This form is comprised of a range of gentler, grade-related multi-unit typologies that hits the sweet spot between the extremes of expansive single-detached housing on the periphery and the point tower condominiums defining cities’ central skylines. These low-rise forms, which could be constructed in timber and be significantly less carbon-intensive than concrete-and-glass towers, are generally well suited to adapting and diversifying low-density, single-use zones where transit and infrastructure are often underutilized.
The creation of more complete and walkable communities – and reduction in barriers on form and use in service of this – is key to curbing our carbon emissions. And this cannot be understated. In a 2011 CityLab piece, Emily Badger drives home how much of a game-changer it could be to loosen zoning restrictions. Citing the work of developer Jonathan Rose, Badger shows that the combined household and transportation energy consumption of an energy-efficient ‘green’ suburban home is still 10 per cent higher than that of a comparable-sized home in a mixed-use urban neighbourhood, 20 percent higher than that of an urban green home, and 30 per cent higher than that of a multi-family urban green home. It isn’t just about making green buildings, but about making complete communities – something smart growth advocates have long understood.
There is an inherent contradiction in zoning that celebrates the idea of place and yet doesn’t fully embrace regional and climatic differences. At a time when globalization and continental standardization of codes have contributed to a sense of placelessness in the modern metropolis, a climate-responsive approach to zoning would manifest a reading of differing geographic conditions. Placelessness would be replaced by the distinctive evolution of each city’s built form, customized to support not only the long-term environmental and economic viability of each particular place, but also its residents’ health and wellbeing.