Accessory Dwelling Units — What They Are, What They Can Do

An accessory dwelling unit, or ADU, is a small house or apartment that exists on the same property lot as a larger, single-family residence. As an independent living space, an ADU is self-contained, with its own kitchen or kitchenette, bathroom and sleeping area.

• Because an ADU is built on a single-family lot as a secondary dwelling, it typically cannot be partitioned off to be sold separately.

• ADUs are a practical option for people seeking small, affordably priced rental housing.

• ADUs are found in cities, in suburbs and in rural areas, yet are often hidden from view because they’re positioned behind or are tucked within a larger home.

• As an adaptable form of housing, ADUs provide flexible solutions for changing needs.

Spread the Word

Download and share the handout Accessory Dwelling Units — What They Are, What They Can Do, a one-page PDF adapted from The ABCs of ADUs, a free publication by AARP.

Learn More: AARP.org/ADUs

"The ABCs of ADUs"

Community Benefits

• ADUs offer a way to include smaller, relatively affordable housing in established neighborhoods with minimal visual impact and without adding to an area’s sprawl.

• ADUs provide a more dispersed and incremental way of adding homes to a community than other options, such as apartment complexes or multistory apartment buildings.

• Since ADUs are custom designed and created, they’re able to fit discreetly into all sorts of locations, including suburban subdivisions, walkable towns, urban neighborhoods — and, of course, large lots and rural regions.

• ADUs can provide young people with rental housing in areas without apartment options.

• ADUs used as rental housing are typically managed by homeowners who live on the premises. Such landlords are less likely to tolerate a destructive tenant.

Livable Lesson Videos

Watch informative videos hosted by Eli Spevak (pictured), an ADU expert and co-author of The ABCs of ADUs.

Eli Spevak

Courtesy photo

Homeowner and Household Benefits

• ADUs can generate rental income to help homeowners cover mortgage payments or simply make ends meet.

• For homeowners looking to downsize, an ADU can be a more appealing option than moving into an apartment or, if they’re older, an age-restricted community.

• Families with young children can use an ADU as housing for a nanny or au pair — or even a grandparent or two, who can help raise their grandkids and be assisted themselves as they age.

• Homeowners can use an ADU as housing for a family member who isn’t yet financially independent (such as new high school or college graduates) and needs temporary housing or has disabilities but can live independently if relatives reside nearby.

• If a homeowner or loved one can’t live alone or is in need of regular care, an ADU can be a viable alternative to a costly assisted-living facility.