The multigenerational household: what's actually driving the trend, and what to plan for

Sharing a household across generations — grandparent, parent, and grandchild under one roof — has gone from a less common arrangement to a genuinely mainstream housing choice. The number of Americans living in multigenerational households has roughly quadrupled since the 1970s, and it’s now common enough that homebuilders are treating it as a design category in its own right, not an edge case (NPR).

What’s actually driving the trend

Two motivations show up consistently in the research, and they’re frequently intertwined rather than separate:

Cost. Sharing a home divides largely fixed costs — the mortgage or rent, utilities, property taxes — across more income earners. Roughly a third of recent multigenerational homebuyers cite cost savings as their primary reason for the arrangement.

Caregiving, in both directions. A notable share of recent multigenerational homebuyers — around 41% — say the primary driver was wanting to care for or support aging parents. The same arrangement frequently runs the other way too: grandparents providing childcare for grandchildren, which connects directly to the scale of contribution described in the grandparent economy.

Builders have noticed: multigenerational features — accessory dwelling units (ADUs), wider doorways, curbless showers, and other aging-in-place adaptations — are now a named priority in home design trends, and listings for multigenerational-friendly properties get measurably more views than comparable listings without those features.

What tends to go well

The research on existing multigenerational households is notably positive on balance. The large majority of families already living this way — in one widely cited study, 98% — describe the arrangement as a successful solution overall. The benefits that show up most often:

• Closer day-to-day awareness of an older family member’s health, mood, and safety, which can catch a developing issue earlier than periodic visits would
• A genuine, mutual support network — grandparents assisting with childcare, adult children handling tasks that have become harder for a parent — rather than support flowing in only one direction
• Real cost savings on housing, utilities, and often groceries, freeing up money that would otherwise go toward maintaining two or three separate households

What tends to cause friction

The same research is honest about the other side: roughly three-quarters of people in multigenerational households also report that the arrangement contributes to stress at times, even among those who consider it successful overall. The recurring friction points:

• Privacy. Even a large home rarely offers as much separation as two fully independent households would.
• Decision-making around money and household responsibilities. Whose name is on the mortgage, who pays for what, and how unplanned costs get split are all worth deciding explicitly rather than assuming everyone has the same expectation.
• Generational differences in habits and values. Differing views on parenting, daily routines, or household rules surface more often when everyone shares a kitchen than when visits are occasional.
• Coordinating schedules. Work, school, and social commitments across three generations rarely line up neatly, and that takes ongoing flexibility rather than a one-time plan.

What helps before moving in together

Families who report this working well tend to share a few specific habits, not just good intentions:

• Setting clear expectations in advance — particularly around shared costs and decision-making authority — rather than letting them get worked out informally after moving in
• Defining roles and responsibilities explicitly, especially around caregiving and childcare, so contribution doesn’t quietly default to whoever’s most available (the same dynamic covered in who handles what, which applies just as much inside a shared household as across separate ones)
• Holding regular family check-ins once living together, not just during the initial planning conversation, since needs and friction points tend to shift over time
• Building in some structural privacy where possible — a separate entrance, a private bathroom, a defined “own space” — even within a shared home

Whether a multigenerational arrangement makes sense for a given family is a personal and financial decision with no universal answer — stay, downsize, or move covers the broader framework for thinking through a parent’s housing situation, of which this is one specific option among several.