'Making  Room for America' at the National  Building Museum in Washington

In the majestic redbrick Italian Renaissance National Building Museum on F Street NW in Washington,  an area that includes the National Gallery and other tourist destinations, a colorful display opened last month that helps Americans come to grips with the country's changes in housing needs.

The "Making Room for America" exhibit is displayed in a colorful, high-ceilinged hall on the second floor of the museum, with orange and green signs proclaiming its message, which is that housing in the United States is based on the needs of a small percentage of the population that has changed dramatically since 1950, when most families consisted of a mom and a dad and their children, the nuclear family.

After World War II, the combination of urban flight, VA loans, available automobiles, a proliferation of highways, and the baby boom worked together to make the single-family home the most popular type of housing in the country.

The problem is that most housing in the U.S. is still  constructed to accommodate nuclear families in single-family dwellings, but the percentage of nuclear families has diminished.

According to census reports, in 1950, 43 percent of U.S. households were made up of nuclear families.  In  2016, that figure was 19 percent.  In addition, in 1950, 9 percent of households were made up of people living alone.  Last year,  that figure was 28 percent.

Despite this, there are now twice as many single-family homes as multi-family ones, and many people cannot find suitable places to live.

In the exhibit, a 1,000-square-foot model house shows three successive solutions to the problem. Each type of housing includes two living arrangements that can be linked or separated by movable walls to accommodate a private area.

The first, the current display, shows housing for roommates.  Many people can afford housing that is more expensive if they have roommates.  About 20 percent of U.S. households consist of adults living with other adults.  In addition, 28 percent of 18- to 39-year-olds share apartments with at least one roommate. The apartment exhibit features a fold-away table, a wall bed, which can save 32 square feet, and storage space built into the walls.

The second display, which will start in a few months, will show an apartment for an extended family featuring a movable wall that creates separate bedrooms for  parents and  children.

During the day, the wall disappears and the room becomes a single living area.  There is a private space with an open bathroom reserved for a parent.

Finally, three months later, the model will show a living space that can accommodate retirees.  The display will show figures indicating that the U.S. senior population is expected to double by 2060.

The senior apartment will feature adaptable and accessible counters and showers with walls that can be folded for seated bathing.  The motorized wall beds are easy to operate.  In addition, the unit would feature a micro-studio to rent to supplement income or accommodate a caretaker.

Chrysanthe Broikos, curator of the exhibit, said, "There needs to be more interest in housing needs for today."

She said the exhibit,  organized by Sarah Watson, deputy director of the New York Citizens Housing and Planning Council,  tries to create an awareness of today's lifestyle and interest in current housing needs.

About  3,000 people have visited the exhibit since it opened Nov. 16. It will close on Nov. 16, 2018.

The National Building Museum is at 401 F St. NW, Washington. It is open from 10 a.m. to 5 p.m. Monday to Saturday and from 11 a.m. to 5 p.m. Sunday.