The biggest challenge facing developers hoping to create high-density, livable communities is not always bureaucracy or funding—it is often the people in the neighborhood, Peter Calthorpe told attendees at the 2015 ULI Fall Meeting.

“NIMBYism is the biggest issue we have to confront,” said Calthorpe, head of Calthorpe Associates, during a panel discussion. Concepts like building dense public housing and taller buildings are often “scary to the people in the U.S.,” the new urbanism advocate said in his opening remarks.

In a far-ranging and lively discussion, the panel—moderated by John Fitzgerald, chief executive officer of ULI Asia Pacific, and Lisette van Doorn, chief executive officer of ULI Europe—provided a broad rundown of the issues inherent in and obstacles to creating denser, more walkable neighborhoods. But the dialogue repeatedly came back to the public perception of high-density projects and the objections found in many communities.

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“One of the problems is we tend to adjudicate these problems one project at a time,” Calthorpe said. The flaw is “not in urban design, it’s regional planning,” he told the audience.

If communities are planned on a regional level, illustrating the big-picture consequences and impacts, then community leaders are often more open to high-density projects, he said.

“When asked to judge one block at a time, the locals shows up,” Calthorpe said. “So I think you need to change the methodology by which we come to these conclusions.”

In Melbourne, Australia, the government went through a process of privatizing utilities to raise money, and then embarked on public/private partnerships to develop infrastructure, including rail, transit nodes, and new roads, said John Carfi, group executive, residential development, for the Mirvac Group. Higher-density development was promoted as a way to capitalize on the value of infrastructure and promote jobs.

“The way they did it was a public campaign linking jobs, infrastructure, and general economic prosperity and growth to density in the city,” Carfi said.

But the panelists made it clear that issues vary around the world and from city to city, emphasizing that not all approaches are appropriate for all cities.

In Asia, Singapore and other cities are embracing high-density development to help sustain the growing populations moving from rural to urban areas, said Scott Dunn, managing director of AECOM. “One thing Singapore did was link public housing to the overall plan,” he said.

However, in Europe, “the rural-to-urban migration ended long ago,” said Alice Breheny, global cohead, research, TIAA Henderson Real Estate. In Europe, there is a “bit of complacency,” she said.

“I think changing the perception on density depends on how the city is performing,” Breheny said. “In London, it is thriving and we have a real NIMBYism thing there and people don’t want more infrastructure if more people are coming in.”

A high-speed rail connection linking London with Birmingham has been opposed in London, but supported in Birmingham, a city in need of a boost. “So they [Birmingham] recognize the benefits of densification,” Breheny said.

Calthorpe threw a twist into the debate when he suggested, “I don’t think high density is the issue. Good urbanization can exist in any density.”

His comments quickly drew a response from Michael Spies, senior managing director, Europe and India, Tishman Speyer, who argued that “density is very relevant” to long-term planning decisions. Most plans, for example, do not distinguish if development is within walking distance of transit.

Density analysis gives planners the opportunity to “avoid bad planning decisions,” Spies said. The real question is about “appropriate density,” which can be defined differently from city to city, depending on the long-term goals.

“Most cities don’t have a handle on where they want to be 100 years from now,” Spies said.

Ultimately, funding is the key issue going forward for many cities, panelists agreed. Seventy percent of the necessary infrastructure in cities will need to be financed by the private sector, Dunn said. In Asia, mass transit projects are already underway in Jakarta, Ho Chi Minh City, Bangkok, Manila, and Kuala Lumpur, he noted.

“There is a lot of opportunity for groups to get involved,” Dunn said. “The challenge will be how that private/public partnership works, in terms of building the infrastructure.”

Carfi agreed that funding infrastructure will be one of the key issues as cities begin to embrace new concepts. But it is not enough to simply build roads and transit systems, he emphasized.

“Investing in infrastructure has to be compatible to high density,” Carfi said.

Other issues on the horizon must be considered, from street lanes to accommodate autonomous cars to the appropriate use of tall buildings. To many, tall-building housing is still synonymous with the vertical ghettos found in many cities.

“You can have super tall [housing] if you have amenities to support it, you have an urban framework that is connected, and you have opportunities for socializing,” Dunn said. “That’s where you add vibrancy to community and life of city.”

But ultimately, many of the issues fall into human behavior and convincing a community of the value of high-density development. In many cases, “part of the education” is convincing people they may have to walk more to reach stores and mass transit, Carfi said.

“The public needs to think bigger-picture, longer-term,” Breheny said. “You have to think it is for the children, really.”

Any successful effort to increase density and develop public/private partnerships must start with convincing the public of the importance of connected, interrelated designs, panelists agreed.

“Ultimately, it really comes down to everyone’s sense of citizenship,” Spies said. “How do we get people to think forward? Ultimately on the individual level, maybe even if they are only thinking of their own descendants.”