Multigenerational ADUs in the Pacific Northwest
Pew + Generations United data, plus what we have learned designing for three generations under one address.

The demographic backdrop
Pew Research documents that the share of U.S. households containing two or more adult generations has roughly quadrupled since 1971. Generations United's own surveys show the trend is voluntary as often as financial — adult children value proximity to aging parents.
ADUs are the most flexible physical answer to that demand: they preserve household autonomy while collapsing distance to zero.
Design implications
Two distinct entrances. Sound separation between sleeping zones. Accessible bathroom in the ADU regardless of current resident age. Galley or single-wall kitchen in the ADU, not because the resident does not cook but because the primary kitchen is already next door.
AARP's Public Policy Institute tracks the caregiving load that drives many of these design decisions.
Sources:AARP Public Policy Institute
What clients tell us 18 months in
The single most common feedback: the unit feels too small for the way the family ended up using it. Multigen households spend more time together than they planned. If the budget allows, build to 1,000 sq ft, not 600.


