Getting to Net Zero

The Living City Design Competition invites project teams from around the world to imagine how existing cities might be retrofitted to achieve all twenty imperatives of the Living Building Challenge, the world’s most rigorous green building standard. Like the standard itself, the competition reflects our belief that humanity has all of the necessary tools and skills to resolve the environmental, social and economic crises of our day. If we are to live up to our potential, however, we must first clearly define what a truly sustainable society would look like. With that powerful and practical vision in mind, we can begin working toward the future we hope for.

The Living Building Challenge’s twenty Imperatives are organized into seven categories, or “Petals”: Site, Water, Energy, Health, Materials, Equity and Beauty. This is the first in a series of posts exploring each Petal and considering how it might be applied to the city scale. We begin with Energy.

Simply stated, the Energy Petal requires that completed projects rely solely on current solar income. To be certified, a project must operate at net-zero energy consumption over the course of each year and all energy must be generated onsite using appropriately scaled clean, renewable resources. Renewable energy is defined as photovoltaics, wind turbines, water-powered microturbines, direct geothermal or fuel cells powered by hydrogen generated from renewably powered electrolysis. No combustion is allowed.

So how can an entire city exist within its current solar income? As with any Living Building Challenge project, these re-imagined cities will have to start with efficiency. Some of the design approaches are straight out of Green Building 101 (proper orientation, daylighting, insulation, etc). The Competition quickly pushes teams into the advanced class, however. The building projects that are currently pursuing Living Building Challenge certification aim for up to 80% reductions in energy use before renewable energy is even considered. This will have to hold true at the community scale as well.

To address these efficiency needs, competition teams will need to take an extremely holistic approach to their design. Beyond considering systems for heating, cooling, lighting and transportation, the teams will have to ask themselves a completely new set of questions. How will new buildings affect their neighbors’ access to solar energy and fresh air? What kind of protocol would teams recommend for retrofitting buildings and neighborhoods? Can landscaping and food production work together to reduce a city’s summer cooling needs?

This competition also heralds the start of a new era of regionalism, one in which builders and planners take the world’s best ideas and translate them to meet the specific needs of each climate, culture and place. This modern regionalism must be built around right-sized infrastructure: a distributed and democratic network of energy generation that is more stable and more secure, easier to upgrade and tied to the local economy.

On the high-tech side, how might smart grids and responsive meters allow cities to distribute energy in a way that supports shifting usage patterns at different times of the day and week? How should zoning be modified to encourage mixed use (reducing commute times and ensuring that energy is not wasted on buildings that stand empty all night or all day)?

For energy generation, competition teams will make crucial decisions about scale. Do the buildings develop symbiotic relationships, using each other’s surplus and shifting distribution according to the time of day or season? Do districts within the city create neighborhood “power plants” in locations particularly suited for sun or wind (or both)? What geothermal resources does a given city have, and how might those be leveraged?

Of course, people are the life of cities, and competition teams will have to consider how people will interact with the Living City of the future. Living Building Challenge project teams involve future inhabitants to an unprecedented degree compared to the conventional design process. While many competition teams likely won’t have the time or resources to involve large citizen groups in their process, they will nevertheless have to ask themselves how people will respond to the energy strategies they propose. Competition teams may choose to call on behavioral scientists or others with insight into the habits and aspirations of a community. In many ways this issue, the human element, will be the most challenging for project teams to address as they work their way through each of the Living Building Challenge’s seven Petals.

Ultimately, the Living City Design Competition is about hope and inspiration. The end product must portray a community that people will want to build. As competition teams dig into the technical puzzle of bringing an existing city to net-zero energy, they will have to keep the life of the city in the forefront of their minds.

Categories: Cities