With London’s population projected to soar past 10 million in the next 20 years, an expert panel at a recent ULI United Kingdom conference in London predicted that new development must go outward as much as it goes up, particularly as newcomers to the capital city find affordability to be their greatest challenge.

While London’s aging population is unlikely to move out of the city center anytime soon, 3,500 members of the creative class are expected to leave London by 2020, said panelist Lee Polisano, president of PLP Architecture. Such a loss would have a significant impact because the presence of artists and other creative workers is an important part of establishing affordable areas such as Shoreditch, which is considered a hip new center, he said.

From left: Adrian Penfold, Baroness Jo Valentine, Lee Polisano, and Sir Stuart Lipton

“Every major city relies on the 23-to-35-year-old generation for its energy, its creativity, and its startups,” Polisano said. “They may get here and have a great time, but it’s useless if they can’t afford it.” His prescription? “Polycentrism. A key component of successful placemaking lies in dispersing London’s institutions to the capital’s emerging centers in areas of severe deprivation.”

With any new space sorely needed to ease the pressure on prices, Polisano said new centers like Old Oak Common would be critical in turning back the tide of the capital’s exodus of the creative class. An earlier panel highlighted several regeneration case studies such as King’s Cross, Old Oak Common, and Birmingham New Street, all of which illustrate the potential of transit nodes to be new mixed-use centers with plenty of developable land.

Baroness Jo Valentine, chief executive officer of London First, took a macro-level view of the systemic challenges facing London, sounding an alarm for what could go wrong if the United Kingdom voted to exit the European Union in the Brexit referendum (which it, in fact, did on June 23). Valentine spoke of a city potentially crippled by Brexit, under which students and tourists would be put off by increased visa regulations.

Paris and Berlin have already surpassed London as go-to spots for retail and technology, respectively. Plans for new rail and airport infrastructure have also stalled. Valentine’s key takeaway: the potential loss of talent and spending could leave the capital’s public realm an investment-starved haven of congestion. While not quite expressing such a bleak view of the future, fellow panelist Adrian Penfold, head of planning at British Land, reinforced Valentine’s point that London needs money—specifically £1.2 trillion (US$1.6 trillion) for new infrastructure.

In addition, London will need more than 1 million new homes in the next 25 years. “Yet already there is no comparison for another city that has increased its population as much as ours without expanding its boundaries,” Penfold said. “We will either need to change the social experiment of the Green Belt [green space that serves as an urban growth boundary around London] or find a way of planning beyond boundaries.”

ULI trustee Sir Stuart Lipton, partner at Lipton Rogers, recommended building out East London to match West London’s density. “Before, [our projected population growth] meant an increase in the number of households of 3.5 million. Now I can see that being hugely surpassed. There is not enough land elsewhere. The infrastructure is there; the opportunity is there,” he said.

And the model for how to do this? The village green is the solution, Lipton said. The historical precedent for mixed uses offered by university, market, and cathedral towns sets a template for redevelopment, he noted, adding that off-site manufacturing could meet the speed of development needed. “Take an interesting town square and build good-quality civic amenities around it. It’s quite simple,” he said.

“This is all nothing new. It just needs to be done with style and quality,” he added. “We just need to work out how we can afford it.”