Cities are our greatest hope.

They are our greatest inventions, and the most important things we will ever build. Most of the people on Earth now live in cities.

They also offer our best hope for long-term survival—and not just survival, but success. For life as we know it.

As Denis Hayes, President of the Bullitt Foundation, says, “Cities offer the best chance to dramatically reduce carbon pollution, provide shelter and community for the world’s growing human population, and protect rural habitat for species in decline.”

Hayes isn’t one to talk without action. Under his leadership, the Bullitt Foundation built and operates the greenest office building in the world, the Bullitt Center. (He also, not incidentally, coordinated the first Earth Day in 1970).

But for cities to “go green,” we’re going to need to push the envelope and change our notions of what’s possible.

At six stories, the Bullitt Center is certified under the Living Building Challenge, the most rigorous benchmark of sustainability in the built environment. It produces as much electricity from solar panels on the roof as it uses in a year—in ever-so-gray Seattle. In fact, in 2014 it produced 60 percent more electricity than it used, making the building net positive energy. And it is 100 percent leased.

The Bullitt Center website says, “The goal of the Bullitt Center is to drive change in the marketplace faster and further by showing what’s possible today. The era of harm reduction, half steps, and lesser evils is behind us. As a society, we need to be bold in ways that were once unimaginable.”

The point of the Bullitt Center is to inspire. To challenge. Can you build something better?

Here are five ways you can beat the Bullitt Center at its own game—which would be a win for all of us.

1. Design for your natural environment.

Your building doesn’t exist in a black hole. It exists in a specific climate, a certain ecosystem. It is crazy to create the same building in Atlanta as in Seattle. Build for your local environment.

“We must recognize that cities—and people—are part of nature and subject to the same laws as the rest of nature,” Hayes explains. “Homes in the American Midwest once sported good insulation for the winter and screened ‘sleeping porches’ for the summer. In the Southwest, thick adobe walls kept dwellings cool during the day, and heat stored in the walls served as a thermal flywheel to keep the homes warm at night.”

Looking to nature for inspiration is an idea as old as Leonardo da Vinci’s sketches of wings from birds. And in 1997, when Janine Benyus released Biomimicry: Innovation Inspired by Nature, a movement was born.

On her website, Benyus describes biomimicry as “learning to live gracefully on this planet by consciously emulating life’s genius. It’s not really technology or biology; it’s the technology of biology. It’s making a fiber like a spider, or lassoing the sun’s energy like a leaf.”

Plus, biomimicry is hot.

The Bullitt Center is built with big windows to maximize natural daylight, given Seattle’s temperate climate and lack of sun. Your environment will have different considerations.

Consider them.

2. If you want to build an ecosystem, you have to think like an ecosystem.

That’s an airy way of saying, “work together.”

Traditional building processes frequently treat design, engineering and construction as different stages. Developers, architects, engineers, contractors are commonly hired separately and touch the plans at different points.

To build the Bullitt Center, they did things differently. The entire development team was assembled before the project began, including the general contractor. Many team members were selected because of prior working relationships.

And then the entire team met weekly for years, through design and construction.

That’s right.

Representatives of Point32 (development and owner’s rep), Miller Hull Partnership (architecture), PAE Consulting Engineers (engineering), Schuchart (construction), and the University of Washington’s Integrated Design Lab met with Hayes every Friday for months.

They solved problems. They presented hypothetical scenarios. They made adjustments depending on new information and recent decisions. They revised decisions they thought were made. They made allowances for the needs of the other group members’ requirements.

They planned in concert.

3. Get creative with the rules.

Chances are likely that at some point in the project, you’ll come up against the proverbial immoveable object—such as your city’s permitting process. This is when you have to be an irresistible force.

Before it was built, many elements of the Bullitt Center were considered illegal. Or rather, as the Urban Land Institute’s case study more delicately puts it, “almost every element of the building had a legal or code-related hurdle to overcome.”

Luckily, the City of Seattle was a willing partner in the project, balancing public safety and energy goals with citywide values around environmental performance and innovation.

Nonetheless, since they had not been tried before, the proposed solar panels that hung over public sidewalks were illegal. The consumption of rainwater was illegal. The graywater filtration in an urban bioswale couldn’t be permitted. The use of compositing toilets in commercial buildings was forbidden.

To make room for the Bullitt Center—and future living buildings—Seattle’s Department of Planning and Development created the Living Building Pilot Program to help identify code barriers and advance green building in the city.

Seattle City Light helped in a number of ways, including partnering with the Bullitt Center to create an innovative “metered energy savings” model to finance energy efficiency. Seattle Public Utilities, Seattle-King County Public Health, and the Washington State Department of Public Health supported efforts to mitigate storm water and infiltrate grey water onsite.

As far as the overhanging solar panels go . . . the city recommended classifying the panels as a sky bridge. This would have required much more structural support than the panels needed and would have greatly increased costs. Hayes and Point32 argued that the 75-foot-high panels formed an awning, and there’s an existing permitting process for awnings. The solar panels went up.

The Bullitt Center has one challenge that is yet to be solved: to use the filtered and potable rainwater from the harvesting system, the building manager has to be certified to operate a public water district. Two years after the building’s completion, the Bullitt Center is seeking approval from the Washington State Public Health Commission to drink ultra-filtered rainwater. The process has involved meetings with the U.S. Environmental Protection Agency, the Washington State Department of Ecology, the Washington State Department of Health, the Seattle-King County Department of Public Health, and Seattle Public Utilities.

Sometimes irresistible forces are slow moving, but they keep going no matter what.

4. Build on what’s come before you.

The Bullitt Center is very transparent about the process of the project and results. Many resources can be found on its website, including the as-built product list and the financial case study.

The development team has spoken freely and openly about the project to many publications, including The Seattle Times and The New York Times.

The International Living Future Institute offers rich resources on its website to guide future developers through the planning and certification process of the Living Building Challenge.

The point is, while you’ll be lauded for beating the Bullitt Center, no one expects or wants you to reinvent the wheel. Build on what’s come before.

5. Act different.

Apple famously asked people to “think different.” Denis Hayes wants us to act different. He wants us to be different.

In an editorial for The Huffington Post, written in 2012—a year before the completion of the Bullitt Center—Hayes wrote, “With a mix of vision and pragmatism, our goal is to do everything right.”

Two years past its opening, it seems the mix of vision and pragmatism worked. The Bullitt Center earned its Living Building Certification. The building is outperforming its energy goals (which always far exceeded code requirements).

But “act different” doesn’t mean “act differently exactly like we did.” Perhaps your living building will harness wind energy. Perhaps it’ll be seven stories tall, or ten. Perhaps it’ll be in a central business district or a neighborhood commercial zone. Maybe you’ll build a complex of energy-sharing buildings, or an eco-district.

The Bullitt Center showed that it could be done. The question now is how to answer Denis Hayes’ call to get the greenest office building in the world replicated a thousand-fold . . . a million-fold. Fast.