Gabriel Metcalf loves cities.

He loves the diversity of people, and the organic ways they can find others like them, while at the same time, being constantly exposed to those who aren’t. He loves walking or hopping on a bike to get where he needs to go. He loves the way cities buzz with energy.

It’s why he’s so disappointed in what he calls “exclusionary policies” that make it so expensive to live in the Bay Area. As president and CEO of SPUR, the region’s preeminent urban planning think tank, Metcalf, a San Francisco condo owner, has been at the forefront of advocating for smarter housing and transportation policies. He was a co-founder of City CarShare, one of the first car-sharing organizations in North America, and a founding member of the San Francisco Housing Action Coalition, a nonprofit that advocates for more housing at all levels of affordability.

He’s stepping down from SPUR after more than 20 years, including 13 as its president and CEO, to take a new job at The Committee for Sydney, another urban planning think tank. This news organization spoke with Metcalf about the ways in which the Bay Area has changed over his tenure at SPUR, what challenges lie ahead and what opportunities await. The conversation has been edited for clarity and length.

Q: How did you first become interested in cities and urban spaces?

A: One starting place is the experience of moving around as a young person, living in Denver, living in suburbs, living in a college town, and viscerally feeling how much place matters. Boulder provided a really wonderful experience of small college-town urbanism in the sense of a very walkable, compact place where you could get everywhere by bike. It has a very healthy public space culture, where people spend time on the street and in the parks. So, some of that interest in cities began as just a lived experience of the quality of life in different places. And, from early on, I knew I wanted to live in a bigger city and get into a bigger world than where I grew up.

Q: How did you end up in San Francisco?

A: My girlfriend and I went to Seattle for a couple of years, and then we moved to San Francisco in 1996 in maybe one of the last years when it was still possible to come here without a job and figure it out, before the city got so expensive that that became impossible. It was a dream to get to live in such a great city. There was so much happening, so many different kinds of people, and I really had the sense that it was a place where it was going to be possible to experiment politically to do things that wouldn’t be possible in other parts of the country.

Q: What makes cities great places to live, in your mind?

A: Cities are a vessel for holding human difference. That’s what a city is. And that essential purpose of holding human difference becomes a platform for a lot of other really interesting things. Cities end up fostering creativity of all kinds because they bring so many different kinds of people together. That shows up in political movements, it shows up in artistic movements, and it shows up in economic innovation, as well. And, it also turns out cities are incredibly ecologically efficient. The city with the smallest carbon footprint per capita in the United States is New York. The essence of the ecological genius of cities is, by concentrating people at high densities, we make it possible to get around by foot, by bike or by transit. So, cities do a lot of different things for us.

Q: How have the cities in the Bay Area changed in the past two decades you’ve been living here?

A: Physically, it has not changed very much. And I think that’s de facto been the choice we’ve made. We’ve decided to keep most of the physical form intact, but at a price of losing a lot of the social fabric.

The most important mistake in the Bay Area is our decision that nothing should ever interfere with the comfort and convenience of people who currently own their homes, that they should not have to be troubled with taller buildings anywhere in their line of sight. If we were willing to make some very small sacrifices, essentially to allow tall buildings to be built, we could make this region less expensive.

Q: Why are people so resistant to seeing taller buildings, or physical change in general, in the Bay Area?

A: This is one of the great ironies of the Bay Area, that attitudes that are clearly exclusionary got labeled “progressive” by some people. The attitude that single family neighborhoods should be able to keep out higher density apartment buildings forever. It’s attitudes like that are clearly harmful to low-income people or immigrants. And, I don’t know why that happens.

Q: Is that the biggest challenge facing the Bay Area right now?

A: It’s one of the challenges. Another big challenge for the Bay Area is transportation. The generation after WWII did an extraordinary thing by planning and funding and building BART. This was in an era when much of the country was still building highways. The Bay Area looked so ahead of the game in the mid ’70s when BART opened, but since then, we’ve really rested on our laurels and have not kept up. We’ve skipped two generations of expanding our transit system, and so today we live with that legacy of under-investing in regional transit. At the same time, we built out so much of the region in the form of low-density sprawl, which means transit does not work there. So, we now face the twin challenges of retrofitting our low-density neighborhoods to become more compact and walkable, while at the same time playing catch up on transit investment.

Q: Is there any hope for us?

A: There is hope. We actually have everything we need to solve these problems. We have such high levels of education. We have such high levels of wealth. We have a very idealistic population. The greatest danger for us is a form of fatalism, where we start to believe these problems are permanent and there is nothing we can do. That is simply not true. We have the ability to solve them. But, we need to come together as a region to change course on housing and transportation.

Gabriel Metcalf

Age: 48Position: CEO of SPUREducation: Antioch College; Institute for Social Ecology; Department of City and Regional Planning, U.C. BerkeleyResidence: San FranciscoFamily: Two boys; partner

Five things to know about Gabriel Metcalf