The two largest generations, Baby Boomers and Millennials, total more than 150 million people combined. And these two demographics—typically childless and therefore less interested in the suburbs—are having a multiplier effect on the movement toward urban living.

The needs and wants of these demographics are already shaping the design and development of the next generation of housing, according to “Urban Wonk” Kaid Benfield, co-founder of LEED for Neighborhood Development, writing in The Atlantic Cities.