With no end in sight to the nation's housing shortage, occupants are increasingly turning to doubling or tripling up to get more out of the space they have. Traditional single-family homes are especially scarce, and along with them traditional single families. At present, the trend in housing is toward "multi": multifamily, multipurpose and multigenerational.

Despite improvements in the economy and employment, growing demand and rising home values, inventories of single-family homes for sale are at near-record lows. The just-released National Association of Home Builders/First American Leading Market Index report of the third-quarter activity finds single-family permits "the weakest element of the index," running at just 56 percent of normal activity.

The National Association of Realtors reported last month that total housing availability of existing homes in September was 6.4 percent below where it was the year before. Shortages are most acute where they are needed the most — at the more affordable and entry-level end of the market.

Colliding demographic shifts also are putting intense pressure on the housing market:

• Younger millennials entering the job market tend to gravitate toward major cities that already are struggling to keep up with high density, increasing demand, gentrification and soaring rents and home prices.
• Older, married millennials are looking to move out of the city and into the suburbs in search of safer neighborhoods, better schools and more green space. But the vast majority of suburban homeowners are opting to stay put rather than sell and buy up or out.
• Older, more affluent baby boomers are considering downsizing or relocating back to an urban environment but have difficulty finding suitable, age-friendly properties.
• The parents of younger baby boomers and Gen Xers are now at or approaching the age when caregiving will become an issue.
• Last May, the Pew Research Center stated its analysis showed that more young adults (ages 25 to 35) were living at home than in any other previous generation.

With lots, materials and labor at a premium, builders have sought to address the shortage crisis with more multifamily units. In recent years, occupancy in multifamily units has reached record highs, but in some cities there now are now more units available than demand for them.

Based on recent projections, Dodge Data & Analytics predicts multifamily construction will retreat next year by 8 percent in dollars and 11 percent in units, stating, "This project type appears to have peaked in 2016, helped by widespread growth across major metropolitan markets."

Yet multifamily in many cases is still the only option for those who choose or must rent, or who prefer an urban lifestyle.

One of the fastest-growing areas in housing at present is the multigenerational home. A recent article for website Realtor.com states, "Nearly 1 in 5 Americans is now living in a multigenerational household — a household with two or more adult generations, or grandparents living with grandchildren — a level that hasn't been seen in the U.S. since 1950."

A number of factors, economic and demographic, are contributing to this trend. Builders and remodelers have responded by offering homes especially designed to accommodate multiple generations that provide a variety of amenities and both communal and private spaces.

The American Institute of Architects' Home Design Trends Survey for the second quarter of 2017 found multigenerational living options growing in popularity as requested home features, up 2 percent from last year. These include accommodations for aging — such as wider hallways, on-grade entries and ramps or elevators — as well as for communal living — such as multiple laundry rooms and universal design features.

In a variation on the multigenerational household, The Washington Post reported recently on a growing trend in which empty-nester baby boomer homeowners who want to keep their current home can make additional income renting out rooms to millennials who can't afford to buy or pay the high rent for an apartment of their own.

An offshoot of the multigenerational trend is the shift toward multipurpose and adaptable spaces. These may be rooms that can double either as sleeping quarters or support some other activity, such as a home office, exercise or yoga/meditation space, or craft or hobby workshop.

An on-site extension or cottage can house guests, aging parents or be offered as a vacation rental property. Young families with aging parents are already thinking ahead, requesting first-level bedrooms and designing nurseries that later can be easily converted into a living area for an elderly occupant.

Americans are coping with the housing shortage in a variety of innovative ways depending on their means and their needs. We can expect to see more multi-pliers in the year ahead as they look to maximize the space they have.