Editor’s note: Welcome to Grist’s presentation of Alex Steffen’s new book Carbon Zero. We’ll be posting a new chapter every day till we’re done — here’s the full table of contents. And this post will tell you a little more about the project. If you like what you read, you can order Carbon Zero from Amazon.

Shelter: working with nature to drop emissions

Once we’re thinking differently about our streets, we need to start thinking differently about our buildings as well. How we build has a major impact on our climate emissions. To see why, we need to look at buildings themselves.

Buildings offer us many things: a place we can feel at home, a status display, a means of expressing our personalities, a productive workspace, an investment tool. But above all else, our buildings offer us shelter.

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Shelter from what? The power of nature. Every day, vast quantities of energy flow through our surroundings. The seasons, the daily rotation of the Earth, the tides, the forces of sun and wind and rain: These are energies far vaster than anything human beings create by burning things. Most of us have only known exposure to the real power of nature — frost-nipped fingers, sunstroke, the misery of trying to sleep in wet clothes in unrelenting rain — through the occasional recreational misadventure. But for most of humanity, through most of history, the elements were a constant and threatening force. Vulnerability to the flows of nature was the most fundamental fact of our ancestors’ lives.

Traditional builders knew and made use of these flows. They had to. Trap the heat from sunshine (with a south-facing window, for instance) and a space gets hot. Block that sunshine (with a high wall or a line of trees, for instance) and that space will cool down. Open a space to breezes, and it will feel cooler. Make that same space airtight, and it will feel warmer. And, obviously, rooms with openings to let in sunshine are brighter than windowless ones. By orienting a building to the sun’s path through the sky and making good use of trees, screens, and windows, the best pre-industrial buildings were often surprisingly comfortable, absorbing the warmth of direct sunlight in the winter and making use of cooling breezes and shade in the summer. You can find examples of this vernacular awareness of seasons and flows in pretty much every culture in the world.

That doesn’t mean that every building worked in perfect harmony with the seasons, or that every building used quality materials, or even that every building was built well. Few of us would tolerate the miserable cold, the overwhelming heat, the bad air, the bugs, and the general discomfort of the huts that many of our bygone relatives called home. It’s easy to forget just how hard life was for most people.

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With the coming of the Industrial Revolution though, cheap coal, oil, gas, and the electricity they generated when burned in power plants transformed the way we thought about the places we lived. They didn’t necessarily lead to more sensible buildings, but they gave us the ability to turn even shabby buildings into comfortable ones — by burning things we made our own sun, wind, rivers, and ice.

We don’t tend to think of things this way, but every fan is an artificial wind, every light an artificial sun, every furnace a hidden fire, every refrigerator a domestic glacier, every tap a tamed river. Since with cheap energy we could run air conditioners, furnaces, and electric lights at low cost, it became both financially easier (and more stylishly modern) to ignore natural forces and build in new aesthetics that often completely ignored the outside world and provided artificially comfort-controlled environments with mechanical systems. In many cases, it was cheaper to use energy thoughtlessly than to spend time thinking about how to use less of it. Comfort came not from a building’s design, but from its thermostats and light switches.

The result? Tens of millions of buildings that are energy oblivious: so poorly insulated that without heat their inhabitants would freeze, full of windowless rooms requiring bright lights even on sunny days, or built with huge shadeless panes of glass that trap so much heat that they are unlivable without constant air-conditioning.

Today, building operations (heating, cooling, lighting, and so on) are one of the major sources of greenhouse gases. When you combine the emissions created by running all those furnaces, air conditioners, and light bulbs with the climate costs of building these structures and making the appliances in them, the result is that our buildings are second only to our transportation systems in their climate impacts. If we’re going to build carbon zero cities, we need to rethink not only the shapes of our buildings, but the way in which they connect to the world around them. We’re going to need to imagine a major upheaval in shelter systems.


What can we do about all that energy use? Well, if we knew that our cities were unlikely to grow much, and so the buildings we had today were going to be more or less the buildings we’d have in 20 years, our strategy would be all about preserving what we have and retrofitting it to be as efficient as possible.

Almost all of us understand that a building can be made more energy efficient. Building owners can insulate and air-seal their structures. They can refit them with more efficient appliances and better lighting. They can install energy- and water-saving fixtures. Even very basic home-efficiency measures can drop energy use for heating and cooling in a leaky, uninsulated building by one-third or more.

Using that much less energy, in turn, can save enough money every month that the payback time for the initial cost is often quite reasonable (and will be increasingly reasonable as energy costs rise). The main barrier here is financing: It’s hard in the U.S. to get the money to make these changes in the first place.

That’s why even the most aggressive retrofitting programs in America involve upgrading only 1 percent or 2 percent of a city’s buildings each year. (Some European programs aim for more than 5 percent, which is much better; after all, the difference between refurbishing 5 percent of a group of buildings every year and 1 percent is the difference between having changed every building in 20 years, and needing a century to get that job done.) Various policies, financing support, and tax incentives can speed up the rate of change. Even in the best case, though, we’re going to have a lot of work on our hands to steadily improve our existing building stock, for years to come.

Buildings for carbon zero cities

If in 20 years older buildings were all we had, that would be the end of this chapter: “Retrofit as quickly as you can.” But for many, if not most, cities in North America, the opposite looks likely to be true. Our cities will not be defined by what we have now, but by what’s coming.

As we discussed last chapter, a combination of fast-rising populations, regional migration, and changing housing preferences will likely mean that in some places, as many as half of the buildings in 2030 will be new construction; in a few places, a large majority will be new. The coming urban building boom presents both threats and opportunities. Our climate goals could be threatened by continuing old practices as we build new cities. Most new buildings today are only somewhat energy and water efficient. If we don’t raise our standards, new construction will be no better. The threat is that we build a flood of new housing, workspaces, and shops that will soon need to be retrofitted themselves, adding to the already difficult task of bringing our cities up to date.

It’s vital that every time a new building is built, we expect it to meet the highest possible green building standards. There are already some excellent efforts pushing for better standards. The Architecture 2030 project, for example, seeks by 2030 to have every new building be carbon neutral, with gradually rising minimum efficiency requirements. It’s an excellent plan, but we can’t wait until 2030 to raise our standards for new development.

Northern Europe’s Passivhaus standard represents the kind of goal we could embrace — practical now and ambitious enough to serve our needs in the future. A city in which every new building was built to Passivhaus standards would be a city on its way to radically reducing the carbon footprint of its homes, offices, and shops.

The German word “Passivhaus” translates literally to “passive building.” Passivity in this case means sticking to two simple core principles: work with (not against) natural flows and use airtight insulation to keep warmth (or coolness) where you want it. There’s more to it than that, of course, but that’s the basic idea. Add to those simple principles the latest design, manufacturing, and materials advances (especially new superefficient window designs) and what you end up with are buildings that work in a different way than most of us would expect.

Anticipating sunshine and shadow can allow architects to use the heat of the sun to warm a building in the winter; they can then employ overhangs, canopies, and trees to shade the building and keep it cool in the summer. Digital design tools for properly orienting buildings to these flows of sunlight and shadow are widely available now.

Our buildings bleed warmth (and coolness); the physics of the world dictate that warm and cold things want to seek balance, so when we heat a building on a cold day (or cool it on a hot one), all of that heat is “pulled” from the house by the difference in temperatures inside and outside. Insulation slows down the process. A little insulation keeps a bit more of the heat inside a bit longer; better insulation a little longer than that. But when you superinsulate a building, the rate at which heat is lost slows so much that much smaller sources of heat can keep it warm. Insulate it thickly enough and make it airtight and even very small sources of heat — like that given off by a candle or the body warmth of a person — can make up for the tiny amount of heat the building loses, keeping it warm without constantly burning fossil fuels.

Passivhaus architects also think a lot about ventilation and insulation. Most Passivhaus buildings have operable windows, situated in a way to maximize the advantages of breezes on moderate days. All use heat-recovery ventilation systems that bring fresh air into the building without wasting the heat inside the house, moving the air but saving the warmth. Some have “heat pumps,” which make use of the cooler temperatures underground or from a nearby body of water to provide energy-efficient air-conditioning.

Such efficiency measures mean Passivhaus buildings stay warmer with very little actual heating (or cooler with little air-conditioning). The result can be a building that uses 90 percent less heating and cooling energy compared to a “conventional” new American home, but is more or less as comfortable (some people find the even temperatures of passive buildings take some getting used to).

That building can be cheaper, too. Large central-air systems and furnaces are expensive. Being able to do without them or use more economical, smaller versions (being able to “furnace dump”) can make the up-front cost of a passive home much lower, even competitive with “conventional” building, while dramatically lowering the occupants’ energy bills — lowering them so much, in fact, that Passivhaus structures all cost less than conventional ones over the life of the building. With more rational government incentives and building codes, meeting Passivhaus standards can even be cheaper up front (and then much cheaper over the long haul).

And here’s the kicker: There’s no downside. Energy used to heat, cool, or light a building serves no other purpose — it offers no other benefits — and nothing is lost by eliminating its use (except perhaps utility company profits). As long as a given efficiency measure pays for itself on a schedule that makes economic sense to the person paying for it, there is no reason whatsoever not to do it. And given the number of ways cities benefit from energy-efficient local homes and businesses, there’s every reason to try to make the economics work as well as possible. When the initial investments are paid off, the financial savings, after all, go straight back into residents’ pockets and the local economy.

Prefabricated buildings present the possibility of even greater savings. Using factory-built sections and on-site assembly, these buildings can potentially offer greater accuracies, more airtight surfaces, less construction waste. Prefab construction may also speed the uptake of specific components and materials, such as high-efficiency windows or the use of bamboo, that offer real sustainability benefits, but which builders have been slow to adopt. Modular construction and prefabrication need innovation, but the potential is very real.

Every time a new building goes up, we ought to be building to the highest currently practical standard. The opportunity costs of not doing so are too great. Every time a construction site opens, we have a chance to save a huge amount of energy for as long as the new building is standing, or to commit that building to wasting energy or undergoing a potentially costly retrofit in the future. Every time we build we have the choice to use the new structure and its systems to help improve the functioning of systems all around it — and we’ll come back to that — or to simply let another building be an additional burden on existing utilities and infrastructure. Every new building is a chance to turn things a little bit more in the right direction.

These new buildings don’t have to be expensive or elitist. I am particularly enamored of the 99K House competition, which asked architects to build a 1,400-square-foot, three-bedroom home, using sustainable materials, passive design approaches, and energy-efficient materials and techniques … for less than $99,000. I found the range of entries to be incredible, proof that plenty of room remains for creative application of cutting-edge green building principles, and that the result can be affordable and accessible.

New building types

If we want to really change things, we can reinvent not only how we build, but what we build. I don’t have space to do the subject justice here, but essentially all of our current housing and commercial spaces are architectural accretions: Their forms represent layer upon layer of historical building technologies, fashion trends, economic class identities, and accidents of practice. Though they are highly evolved to be what they are, what they are is not all we might want.

Indeed, most of us put very little thought into what we want from our homes and workplaces. And while certain general principles seem to hold true most of the time — for example, people like natural light — the range of possible expressions of those principles is wide and still largely untapped. We might, just as one example, see more types of “multi-family” housing built for groups of single adults (the most rapidly growing household type) who wish to live with some degree of common space and community feeling, while retaining privacy and independence.

Though political pressures against innovation are huge — everyone from NIMBY reactionaries to architecturally minded fans of “aesthetic cohesion” in neighborhoods will line up to hate a new type of building — some even stronger pressures are building towards an upheaval in architectural practice. This would be an excellent time for those with the ability and resources to encourage experimentation.

Historic buildings and bespoke innovation

Though it’s easier to build new buildings when we want to live in truly energy-efficient ways, older buildings, and historic buildings in particular, offer opportunities we shouldn’t overlook. Historic buildings can play a critical role in fast-changing communities.

Historic buildings offer community benefits outside their own energy use. Historic buildings can help an area with a lot of new development retain a distinct character and sense of place. They make the streetscape more attractive (especially since many historic buildings were originally designed to serve pedestrians). They also tend to raise property values nearby, helping to increase neighborhood prosperity. Finally, many old buildings are just beautiful.

With strong incentives, many older buildings can be retrofitted up to Passivhaus standards. Though it costs more money and effort than just insulating and weather-stripping, retrofitting older buildings can often drive the energy savings up near that 90 percent mark as well.

A complicating factor is that every historic building presents a unique situation. Each historic building has a specific history of use, change, damage, and remodels. Historic buildings have strange mixes of materials, hidden structures (and structural problems); they may be regulated in different ways than new construction. Smart solutions to the problems historic buildings face are by necessity one-offs — bespoke.

In this regard, heritage structures differ only in their extremes. The fact is cities are built of nothing but unique cases; every neighborhood, every site, every building differs in ways large and small. Though it’s easy to describe the general principles we want to apply in creating a landscape of low-emissions buildings, we must not, as Paul Saffo likes to caution us, mistake a clear view for a short distance. In reality, applying those principles will be a matter not of blanket fixes but of myriad custom-made solutions, applied with insight and creativity. We’ll need an army of boundary-pushing architects, designers, engineers, and builders to transform our cities building by building. We’ll also need a new understanding of what makes a building green, followed by an even bigger suite of tools for crafting custom responses to each green-building challenge.

People-focused places and green building

We’ve inherited a warped vision of what a green building looks like, especially in North America. Strong leadership displayed by green-building pioneers in the 1970s and ‘80s — many of whom were hippies and had a strong preference for independent lives and back-to-the-land lifestyles — has led many of us to associate green building with “living off the grid.” The “neighborhood sustainability” movements of the 1990s and 2000s, with their focus on transitional technologies and small-scale local action, left some of us thinking that green building is fundamentally a small-scale, grassroots project. Other prominent design trends (like the idea of “zero energy” homes, which through photoelectric panels or small wind turbines create as much power as they use) have convinced us that green building is, in fact, a matter of greening specific buildings one by one. Conversely, the last decade’s photos of large modernist single-family homes in forests or deserts or by ocean bluffs have given us the sense that green building is something for rich people’s summer homes and magazine-showcase houses; that it is expensive and exclusionary.

Now, I’m not interested in trashing any of these efforts. They got us as far as we’ve come, often in the face of active opposition and steep learning curves. Many of the structures born of these movements offer terrific illustrations of principles we’d all do well to learn more about — but they do not necessarily offer the best models of the practices we need to embrace. Fundamentally, that’s because they’re not genuinely urban.

Density is the foundation of all truly green buildings. Living urban lives within compact communities is what makes possible the shift from greener structures to truly low-carbon homes and workplaces.

How? Homes in compact communities tend to be smaller. Smaller homes take fewer resources to build and use less energy to live in comfortably. The shared walls of multi-unit buildings make them more efficient. Better-designed larger buildings can also take less work to maintain than a comparable number of stand-alone houses, which translates to lower emissions. People living car-free lives don’t need parking, either, meaning the buildings they live in don’t need parking structures. This can save $10,000–$30,000 in costs for each unit, and shave as much as 10 percent off the building’s carbon footprint. A study for the EPA found that multi-unit homes in compact communities used half the energy, on average, of large-lot suburban homes — without using any different materials, technologies, or designs.

Just as importantly, we live differently in more moderately sized city homes, as well. A home stocked with smaller appliances and less furniture has a smaller carbon footprint. People with less storage space think twice about purchases they’re about to make, and, trend-watchers say, tend to buy fewer things overall. (At least they do on average — some people pack small homes to the rafters!) The shared services in a compact neighborhood are more sustainable than multiple individual versions; for instance, a 500-building neighborhood with one large gym is more sustainable than 500 buildings with individual home gyms. We’ll come back to this different way of living — and the ecological implications of different patterns of consumption — in the next chapter. For now, it’s enough to note that density and green living work nicely together.

Density makes the systems connected to the buildings work better, too. The infrastructure serving each building works more efficiently when the homes and offices in those buildings are more modestly sized. The United Nations’ State of the World’s Cities report makes no bones about it: “The concentration of population and enterprises in urban areas greatly reduces the unit cost of piped water, sewers, drains, roads, electricity, garbage collection, transport, health care, and schools.” Green homes in compact communities make the existing infrastructure do more work, more efficiently. They can do something more, though: They can make it realistic to change the kind of infrastructure we use.

District systems

When communities densify quickly, they encounter an opportunity to upgrade the systems that serve them. In a low-density area, with few new homes, there’s little reason or financial justification for local governments to go to the huge expense and trouble of digging up existing pipes, wires, and sewers and replacing them with the latest alternatives. In some cases, replacing old systems in spread-out communities costs more energy and money than the financial and ecological benefits of the new system are worth. Upgrading sprawl is often not cost-effective.

But when an area is both compact and rapidly changing, that equation is tossed on its head. The density of the community means more people using the systems, and thus more users to pay for the cost of upgrades (and more efficiencies in operation, as I explained above). The amount of new construction, meanwhile, means that a certain amount of digging, repair, and infrastructure development is going to happen anyway, as a natural part of the construction process in a city. People-focused neighborhoods with a lot of new buildings give local governments and utilities the motive and the opportunity to innovate.

District solutions arm them with the means. District solutions are infrastructural improvements that work for a number of buildings in the same area, helping them all get better-performing infrastructure at the same time, without having to rebuild the entire city’s urban systems all at once to do it. Done right, they are relatively fast, cost-effective, and transformative.

Perhaps the classic example is district energy. A common and successful form of district energy is a local combined heat and power (CHP) system. CHP often involves producing electricity with a steam turbine (commonly by burning relatively eco-friendly biomass like wood pellets) to make electricity while capturing the extra “waste heat” thrown off in the process and using it to warm local buildings as well.

What is waste heat? We all encounter it on a regular basis. If you’ve ever driven a car and noticed the hood was hot after you got out, you’ve encountered it. Burning gasoline releases an enormous amount of concentrated energy, but internal combustion engines can only use so much of that energy in actually propelling the car — the rest simply heats up the engine. It serves no purpose (unless you’re one of those folks who likes to cook food wrapped in tinfoil on top of your engine while you drive). It is wasted heat. Waste heat is also what makes an incandescent light bulb hot. Waste heat is always a sign we could be doing better.

Capturing waste heat can provide warmth in an extremely efficient manner. Waste heat can even be stored, using underground liquid “heat sinks” and systems of pumps; these in turn can be linked together with geothermal systems that use the more constant temperatures underground to heat (or cool) the buildings above it.

District energy and smart grids

But heating and cooling are not the only services district systems can offer: They can also introduce intelligence and adaptive capacity into dumb infrastructure. Many of us probably know about “smart grids,” electrical systems that let energy flow both into and out of buildings, measured and controlled by computerized systems. We’ve probably all heard how smart grids can cut down on inefficiencies, and can help route around problems, making blackouts and crashes less likely.

But what we might not have thought about is how many possibilities smart systems offer at the local level. Let’s start with power production. Though it’s certainly possible to put up your own solar roof tiles or wind helix turbine or whatever, numerous problems persist. You may not live in a building that’s well sited to make use of these. You may not use power at the right times to make optimal use of the system. You may lack the money to buy adequate storage. Or, your regional utility may not buy the power you generate back at a rate that covers your installation and maintenance costs. A whole field of companies has sprung up, trying to solve the problems of home-energy systems, and lots of progress is being made; but the fact persists that single home systems hooked up to large utilities are not as easy, cost-effective, or efficient as they might be.

But take a number of homes, a number of local energy systems, and a smart grid, and you’ve got the pieces for quickly improving the local energy infrastructure. A number of supplies and a number of users makes syncing supplies and needs more efficient, and offers the ability to build energy storage at a larger scale and lower cost. If the cars that remain in the neighborhood are electric vehicles, their recharging stations and batteries can become part of that storage capacity. If appliances with jobs that can wait (like a dishwasher) are linked to the smart system, then demand management gets easier, since the appliance can be programmed to do a task (like start the wash cycle for the dishes) only when supply is high and demand is low. Finally, smart systems allow the users to monitor their electricity use directly, and people use things differently when they measure them.

My favorite example of the last point is the Prius Effect. The story goes that if you take two cars that are in every way identical, except that one of them has a mileage meter and the other does not, the car with the mileage meter will get better mileage. At first, this seems dubious: If the cars are the same, how could one get better mileage than the other? The answer is that as drivers note their mileage on the meters, they get a constant stream of feedback on their driving. They notice that when they floor it as the light turns green, driving fast and braking to a stop, their mileage drops; it rises again when they accelerate more gradually, drive a bit more slowly, and brake less frequently. In effect, the car teaches them how to be better drivers.

This same kind of metering effect holds true in all sorts of systems. Feedback makes us smarter. For instance, multiple studies have shown that home energy use drops when energy meters are brought into the home and put in a prominent place, even when no other actions are taken. And we’re not talking about a minuscule drop, either — the reductions in energy use range in studies from 7 percent to 12 percent. Comparing usage between different people or households has an even stronger effect. Several projects have shown that when high-volume users are shown that their energy or water consumption is higher than their neighborhood average, they become more willing to invest in energy- and water-saving improvements, and may become more conscious of their behavioral choices.

More visible information may also make clear just how much energy we can save without in any way impacting the quality of our lives. Consuming less energy will not make us poorer. Huge amounts of power are wasted every day — we generate that power, move it, and consume it, yet it does absolutely no good for us at all. Squeezing the energy waste out of our communities — and this is a matter of systemic design to eliminate stupid, repetitive waste, not choosing to shiver in the dark; it is an engineering problem more than a behavioral one — would make a modest yet meaningful dent in our buildings’ carbon footprints just by itself. Better yet, it would free up money and time for more important things. All those efficiencies mean savings, and those savings add up quickly.

At larger neighborhood scales, these systems can be even more cost-effective, particularly when the local governments expedite work to avoid costly delays, and neighborhood businesses and residents purchase products and services together in order to leverage the best deals. Communities can encourage cultural collaboration and experimentation of a kind and intensity that society as a whole can’t match. A whole neighborhood of people who were excited to go “net zero” might find themselves happily taking steps that might feel onerous if they were acting on their own; they might, for example, be more likely to slim down to an electric car, buy more-efficient appliances, and be a bit more competitive about turning off unneeded lights. These steps, in turn, could make the whole smart system work better and more effectively.

The electric car angle is worth noting. We must change cities so few people need to drive (see the section on electric cars in chapter 3). That said, smart grids offer us an even stronger incentive to see the cars that remain converted quickly to electric vehicles. Electric cars are essentially battery packs on wheels, and since most cars, even in auto-dependent suburbs, stay parked in one of a few places for more than 20 hours a day, having a lot of electric cars means having a lot of batteries plugged into the grid. Since charging stations are programmable, cars can easily be fully charged when they will be needed, but store and feed energy back into the grid when they’re not. This means that the “peak load” of power usage can be met in part by stored-up energy created at other times, a very useful thing when dealing with renewable energy sources that are intermittently available. (We don’t want to buy EVs just for their batteries, though. Simply building more storage capacity into local systems is a better economic and ecological bet than buying electric cars to fill that role.)

What’s true for energy systems is also true for water. “Smart pipes” is a buzzword for various monitoring and measuring systems designed to do for our water use what smart grids do for our energy use. Many water-saving measures (like low-flow showerheads) are already available, of course. Adding smart-pipe systems allows the demand for water to be handled more intelligently. Why talk about water at all in a climate discussion? Because water is energy intensive: It takes energy to capture water, to store it, to pump and purify it, to deliver it to homes and businesses, and to treat the resulting wastewater. And since every one of those steps can be done in more intelligent ways, and every part of these systems can incorporate a variety of water supplies, alternate water uses, and ways of treating wastewater (as we’ll see later), smart pipes might mean a leap in water conservation.

Innovation zones

We have tons of design and technology innovations left to discover in every one of these fields, both in principle and practice. We need to learn a lot about applied innovation in an urban context, and we need to learn it quickly. We need experimentation, risk-taking, new approaches, and just plain creative weirdness. Most of all, we need permission to fail.

And there’s the rub. Most cities have elaborate codes, accreted case by case over decades, designed specifically to avoid failures, almost at all costs. Now, overall, most of the original intentions behind these codes were unimpeachable. Bureaucrats compiled them to protect citizens from known hazards and unscrupulous landlords, contractors, and developers. They compiled them because people sickened or died, were cheated or injured by the practices the codes are designed to prevent. Many of them remain in force for two reasons: First of all, the inherent dynamics of government make it far more likely that someone will be inspired or pressured to add something to the code than to spend time eliminating unneeded parts of that same code. Secondly, property owners are inherently conservative about their property values and often believe that these codes protect those values; therefore, they view change as an economic threat. (Because they allow safely awful projects, codes in actual practice in most cities rarely protect anything of importance. If the average property owner realized what monstrosities are generally within the permitted range of most codes, they would rest less easy, but that’s a story for another time.)

So while these codes often sprang from a desire to protect the public, many of these same codes are out of date. Many are full of contradictions; many are needlessly inflexible. Anyone who’s been around sustainable urbanism for a while can tell you stories of great projects, projects everyone — the neighbors, the builders, the banks, the bureaucrats, everyone — likes getting wrapped up, mummy-like, in red tape. In timid, corrupt, or conservative local governments, code is often actively used to discourage and delay innovative projects, for any of a variety of reasons. Even in communities with forward-looking and well-run local governments, innovation in the built environment is often a matter of figuring out how to permit a practice despite the code. For some projects, these kinds of costly delays simply cut into the profit margin and disincentivize risk-taking; other projects are rendered financially untenable. The most interesting experiments are often the ones that are most entrepreneurial and novel, but these same projects are often the ones with the most tenuous financing. For these projects, red tape means death.

And yet it is precisely these kinds of projects that expand the range of possibilities in our cities, that bring new solutions into play, that help change the thinking of professionals throughout their whole fields. To lose scrappy, start-up attempts by architects, planners, engineers, and place-based businesspeople is to lose your edge. Without an ecosystem of small risk-takers expanding the boundaries of the possible, the projects bankers are willing to invest in will change very slowly, if at all. Successful examples make the best arguments.

One solution? Create specific, legally defined areas where codes and regulations are stripped to their minimums, and bold thinking is actively encouraged. Projects in these special innovation zones would need only prove that they avoid very basic hazards — public health risks, unsound structural engineering, toxic pollution, fire — and that they meet larger legal standards that the city is powerless to change (for instance, that no explosives are produced, all appropriate professionals are licensed, and that no racial discrimination is practiced). Beyond that basic set of strictures, they would have the capacity to challenge constraints, try new things. They might even be able to experiment with financial models, looking to crowd-funding or microbanking, for instance.

Every city needs a place where innovators are encouraged to try new things and take chances, and at entrepreneur’s pace — not the normal glacial pace of bureaucratic process. Currently underutilized or abandoned areas can be turned over to small- and mid-scale experiments in carbon zero work, commerce, and living. Think of them as seedbeds for new urban ways of life. Such zones could quickly become hothouses for growing the kinds of urban innovation carbon zero cities need. If they bloom, they will certainly draw the kind of creative young people every city hankers for — what many of the brightest of the next generation want most of all is to participate in making a better future. Done right, these innovation zones could change the economy of their entire region, as well as greatly accelerate climate-friendly technologies, designs, and start-up businesses. The ability to create innovation zones might even prove a new advantage struggling cities have when competing with more prosperous ones.

But it’s not just buildings and infrastructure we need to reinvent. How we live within our cities also demands reexamination, and there, the possibilities prove even more unexpected, as we’ll see in the next chapter.

Read on: Consumption: Sharing capacities to cut carbon