Maine is the oldest state in the country. So more families here answer “where will Mom and Dad live?” with an in-law apartment in the backyard. Many also answer “where will the kids live?” the same way.
Maine’s median age was 44.8 in 2024, the oldest of any state.1 Anyone who’s had “the conversation” with a parent knows what that number means. The house is too big, the stairs are getting harder, and the driveway is a lot to plow in February. Yet nobody wants to move an hour away to a facility, away from friends, church and grandkids.
In fact, most older Americans feel the same way. AARP’s 2024 survey found that 75% of adults over 50 want to stay in their homes. Similarly, 73% want to stay in their communities. One in four older homeowners say they’d consider building an ADU. The top reason is to make space for a loved one who needs care.2
Three Maine families, three ways to use an in-law apartment
However, not every Maine in-law apartment works the same way.
Parents move into the ADU. In Falmouth, one set of parents moved into an 840-sq-ft attached ADU in the winter of 2023. Meanwhile, their daughter, her husband and their son live in the main house. “It’s priceless,” Mom told the Press Herald. Her daughter put it this way: “I raised my baby into a toddler with my parents next door.”3
The adult child moves into the ADU. In Cape Elizabeth, A single professional lives in a 750-sq-ft cottage in her parents’ side yard. Her father has the best line on how close is close enough: “Our daughter is 25 feet away from us, but we’re feeling like we’ve got an empty house.”3
A renter pays for staying put. In Yarmouth, one homeowner spent years trying to turn her 325-sq-ft studio into a legal apartment. The 2022 law finally settled it. As a result, the rent now helps her stay in the home she loves.3
What our neighbors are doing
The rest of New England is moving the same way, too. For instance, Massachusetts legalized ADUs by right in 2025 and approved 1,224 in the first year across 217 communities.4 In Sudbury, one couple, both 67, built a 900-sq-ft backyard home and moved into it. Then they sold the main house to their son at a discount. Now they help with childcare for their granddaughter. “I’ve had my friends go: ‘Aren’t you going to get on each other’s nerves?'” they told the Washington Post. “Yeah, probably, but that’s family.”5
Similarly, in Rhode Island, a 72-year-old has lived for nine years in a 408-sq-ft ADU at her daughter’s home. “My goal was never to live with my children,” she told AARP. She calls it “the smallest place I’ve ever lived and probably the freest I’ve ever felt.”6
Around here, that model fits a Standish or Windham lot even better than a Boston suburb. After all, there’s more land, fewer neighbors, and often a barn or garage already standing.
Design your in-law apartment for 20 years, not two
An in-law apartment should work for someone at 70 and still work at 88. For example, South Portland’s ADU guidebook recommends “single floor living, a bathroom on the main floor.”7 Here’s what we build into every in-law apartment:
- One level, no-step entry. A short ramp or a graded walk, not three porch stairs that ice up.
- Wide doors and clear turning space in the bathroom and bedroom, in case a walker or wheelchair ever comes into the picture.
- A curbless shower with blocking in the walls, so grab bars can go in any time.
- Lever handles, good lighting and outlets at a comfortable height. Small details that matter every day.
- A heat pump and a tight shell, so a fixed income doesn’t go to heating oil.
- A clear view of each other’s doors, but not each other’s windows. Close enough to help, far enough for privacy.
Have other conversations, too
The families who are happiest with their ADUs talked through the hard parts before they broke ground. Who pays for what? Is there rent? What happens to the unit later? Later, an in-law apartment built for Mom often becomes a college kid’s place, then a caregiver’s, then a rental. As one ADU builder told AARP, “You’ll be able to use it for parents first, and then kids coming home from college, and maybe a rental.”8 In fact, designing for all of those uses from the start costs very little extra.
State law is protecting that flexibility, too. By July 1, 2027, no Maine town will be able to require the owner to live on the property. Some towns, like Standish, already don’t.9
Thinking about bringing a parent closer? Kota’s free lot check will tell you what fits on your property and what it’ll take. See how Kota makes ADUs happen →
Sources
- Maine State Economist (DAFS), 2024 population estimates, July 9, 2025. maine.gov
- AARP Public Policy Institute, 2024 Home and Community Preferences Survey. aarp.org
- Hannah LaClaire, “Who is building ADUs in Maine?” Press Herald / Central Maine, May 6, 2026. centralmaine.com
- Mass. EOHLC, first-year ADU data, Feb. 2026. release (mirror)
- Julie Z. Weil, “For some families, the answer to the housing crisis is in the backyard,” Washington Post, July 5, 2026. via Yahoo
- Miriam Cross, “How ADUs Make Housing More Affordable for Older Adults,” AARP, updated Aug. 20, 2026. aarp.org
- City of South Portland, ADU Guidebook, April 2023. southportland.gov
- Patrick J. Kiger, AARP, Feb. 10, 2022. aarp.org
- 30-A M.R.S. §4364-B(4)(E), added by P.L. 2025 c.385; applied to all towns from July 1, 2027 by P.L. 2025 c.733. chaptered law
