Building a home to provide shelter is one of the most basic of human needs; still, it is one of the areas most in need of innovation. It is not for lack of trying or bright ideas. Today we know how to 3D print houses, and integrate solar cells in windows, roofs, and walls, we can even construct new buildings from recycled concrete slabs. Still, the buildings rising outside my windows are only superficially different from the blocks that went up 50 years ago. It is time to stop thinking and start doing something different. History has shown us that practical usage is the only way innovation will have any impact at scale.
It might be helpful to reflect on why so little innovation finds its way into modern construction. Employing new technologies is inherently risky and costly. It requires expertise, which is hard to find and will remain hard to find until the technology is mainstream. That means developers are faced with increased risk, costs and prospects of delay if they want to find more innovative and sustainable ways to build new properties. This, of course, means that the incentives are low even if developers want to change the way they build. Consequently, innovation in the construction sector is faced with structural obstacles that dampen any change. The question is how to resolve this problem.
Learning from building revolutions of the past, it is clear that it has to come from the political level. But not necessarily from lavish infrastructure spending plans or other kinds of subsidies but from the most straightforward tool of city planners: zoning, regulation and building code. But this is just the tool; what should be the guiding light?
As Geoffrey West has argued in his book Scale, it seems clear that the city is the habitat of future humans; a majority of people on earth already live in cities, and even the possibility and opportunity for still more jobs to be done from home seems not to change that fact. Still, cities face challenges in growing and continuing to supply the needs of their people. In many ways, as Kennedy et al. demonstrated in their article The Changing Metabolism of Cities, a city can be considered an organism with a metabolism of flows that keep it alive. The essential metabolism of a city involves Energy, Water, Waste, and Food.
The COVID epidemic and wars in Ukraine and Palestine have shown that these metabolic flows are more vulnerable than we realized. One of the challenges of the modern world is that the metabolism is still dominated and conceptualized in a centralized manner: Energy is produced in a limited number of massive power plants. Waste is reprocessed in extensive facilities, water is provided by large waterworks, and virtually all food moves through a few enormous distribution centers. While this does provide ease of management and economies of scale, it also increases vulnerability for the city since the centralized nature often provides a single point of failure for these flows.
While there is currently no viable alternative to this approach, another complementary path that can become the basis of the future city is to switch to a decentralized orientation. A focal point for such a path would be the idea of a sustainable and self-sufficient block or other convenient unit. The basic idea is that each city block (or other similar unit) must move towards being self-sustaining in Energy, Water, Waste, and Food. This is quite a journey, but different tiers could be put in place to move towards this goal. This is where zoning comes in as the right tool to enforce and incentivize innovation. However, it is essential that these laws should not be too specific in terms of choosing the technology; instead, targets should be specified, leaving it open to the market to find the best solution. Let’s take a look at what could be done with the most important flows.
Energy
For energy, city planners could require a percentage of the block’s energy consumption to be produced locally using sustainable energy sources. That leaves open the choice of whether to use a geothermal system, cover the facade with solar cells, or use windows with solar cells. In some places, it might even be possible to use miniature wind farms built into the structure. The options would be left open to the developer to choose, and market forces would shape the best-fit innovation. It should also be possible to export energy back to the grid or store it in times of excess.
Water
For water, it is essential to lower usage. That could be done by warranting all heating to be done through a closed-loop water system integrated into the building floors. A percentage of wastewater should be recycled or captured locally. Options are then open as to how that could be done. It could be that water from the kitchen and bath is filtered and recycled for flushing. Rainwater could be collected for the same purpose or for irrigation of rooftop gardens and hydroponic farms. the block should allow the export of excess recycled water to nearby blocks.
Waste
Many modern cities are already doing a lot to recycle garbage, which is sorted locally. It should, however, be possible to do more locally than just sort it. City planners could require composting for use as fertilizer, which can be used in local gardens. Another area of recycling would be furniture, where neighbor-to-neighbor marketplaces should be made available. A simple recycling shop would make a significant impact. The last area is electronics, where facilities for recycling rare metals or decomposing electronics into recyclable chunks should be made possible. The next step could also warrant plastic recycling and waste combustion to generate energy.
Food
In the modern city, food is ubiquitous in stores, but some things are better and healthier to produce locally. There are already many examples of rooftop farming taking off driven by idealists. Respectful of the difficulties associated with producing food, a small percentage of food consumption could probably realistically be grown locally. This could also be achieved through hydroponic farms in the basement or in each unit. It should not be required to be consumed locally, though, since it would be better to leave open the possibility for local advantages leading to specialization. One block might have a massive hydroponic basement farm where fresh herbs are grown in excess, another a rooftop farm producing tasty honey, while a third has a built greenhouse for delicious vegetables.
This is just a thumbnail sketch based on my book Demystifying Smart Cities, and the details can and will vary depending on geography and other factors. The important takeaway is that for innovation in construction to take off, a new approach will have to be built around the incentives that drive the development process. An excellent way to do this is to dust off the age-old tool of zoning laws to provide a path for a more decentralized and sustainable city in the future.
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