The days of large single-family homes on generous lots in big developments may be coming to an end.

The latest data from the American Institute of Architects’ Home Design Trends Survey found that its members are seeing a growing demand for smaller, simpler homes in walkable neighborhoods.

Interest in small, custom-designed homes with simpler exteriors was reported by roughly a third of the survey’s respondents, up from about 1 in 4 respondents a year ago. More than half of respondents reported increased demand for higher-density developments and multigenerational housing. Interest in walkable neighborhoods, mixed-use facilities in neighborhoods and better access to public transit is also up.

“Given the increasing problem of housing affordability, building smaller, simpler homes with greater density and accessible to public transit is essential. As a result, the increasing preference for urban infill locations over far-flung exurbs continues to reshape our neighborhoods,” said Kermit Baker, the association’s chief economist, in a release. “Whether nestled in bustling cities or quieter suburbs, people increasingly seek communities that seamlessly combine convenient public transit access, walkable streets, proximity to employment hubs, vibrant retail options, and generous open spaces – all fostering a well-connected and enriched lifestyle.”

Tri-City housing experts have noted that more townhomes and multifamily homes are being built, particularly in open lots scattered throughout the cities. That’s what may allow millennials, the next generation of homebuyers currently entering their prime earning years, to finally get into the housing market as current homeowners stay put in existing homes, they say.

“If you can get into a townhome for two-thirds the cost of a detached single-family home, you’re going to do it. It gets you in the door,” Jeff Losey, executive director of the Home Builders Association of the Tri-Cities, told the Tri-Cities Area Journal of Business in December.