Following World War II, the combination of urban flight, cheap V.A. loans, reliable automobiles and highways, and the Baby Boom conspired to make the single-family home the most common type of housing in America. And the trend has endured. According to a Census report, in 2015 roughly 76 percent of all housing was single-family.

But household formations have changed considerably since the postwar era. In 1950, nuclear families—defined as a married couple living with one or more children—made up 43 percent of all households. Last year, they made up only 19 percent. In 1950, 9 percent of households consisted of one adult living alone. In 2014, that figure was 28 percent. Despite these demographic shifts, housing development seems frozen in time. Last year, there were more than twice as many new single-family homes built as multi-family units.

The discord between the way people live and the type of housing being built contributes to the United States’ housing crisis. “Not only do we not have enough housing, but we don’t have the right housing,” says Chrysanthe Broikos, curator of Making Room: Housing for a Changing America, an exhibit at the National Building Museum in Washington, D.C., meant to spotlight answers for today’s lifestyle needs.

“We need to be true and realistic about how we are living, and provide a menu of options for how people are living,” says Sarah Watson, deputy director of the New York City nonprofit Citizens Housing and Planning Council (CHPC) and one of the show’s organizers.

The exhibit explores the possibilities of what those typologies might look like. Its centerpiece is the “Open House,” a 1,000-square-foot mock apartment that can be reconfigured to meet the needs of three household formations underserved by the country’s housing stock. Making Room runs Nov. 18, 2017, to Sept. 16, 2018.

The Roommates

It’s no surprise that renters can save money by getting a roommate. These savings, combined with increased student loan debt and a trend toward delayed marriage, help explain why 20 percent of U.S. households consist of adults living with roommates or adult relatives, according to CHPC. The arrangement below is meant to be shared by two individual adults and one couple.

The Extended Family

In 2014, 60.6 million people, or 19 percent of the U.S. population, lived in a multigenerational household. In this scenario, movable partition walls create separate bedrooms for a child and a parent at night. During the day, these two rooms become a single living area. The private space with its own bathroom is reserved for a grandparent.

The Retirees

Some 10,000 Americans turn 65 every day, with the senior population, now numbering 46 million, projected to more than double by 2060. Open House’s retiree mock-up is designed to be especially adaptable and accessible, with wheelchair-friendly features like a height-adjustable kitchen counter.