Designing an ADU for Aging Parents: What to Think About Before You Build
If you're thinking about building an ADU for your mom or dad — or both — you're in good company. Multigenerational living is one of the top reasons New Yorkers are exploring ADUs right now.
But designing a space for an aging parent isn't quite the same as designing one for a young renter or a recent college graduate moving back home. There are a few specific factors to consider that can make the difference between an ADU that works beautifully and one that becomes a source of frustration.
Think About Accessibility from the Start
This is the big one. Even if your parent is completely healthy, they will likely have mobility challenges as they get older, and your ADU needs to account for that. Some things to consider:
Single-level layout — No stairs if you can avoid them. Everything on one floor.
Wide doorways — At least 32 inches, ideally 36 inches, to accommodate a wheelchair or walker if needed
Step-free entry — A ramp or flat threshold at the entrance, not steps
Grab bars in the bathroom — Easy to install, makes a huge difference
ADA-compliant door handles — Lever-style handles are easier to open than round knobs
You don't have to design for a wheelchair from day one, but building with future accessibility in mind means you won't have to tear things apart later.
Keep It Close, But Give Them Space
The whole point of an ADU is that your parent is close — but has their own home. That means the ADU needs to feel like a real, independent living space. Their own front door. Their own kitchen. Their own bathroom. Their own life.
At the same time, proximity matters. A backyard cottage is great because it's steps away, but far enough that everyone has privacy. A basement apartment can work too — though be mindful of stairs and accessibility.
Safety Features Matter
Aging parents may need extra safety considerations built in:
Good lighting — Brighter than you think, especially in hallways and the bathroom
Non-slip flooring — Especially in the bathroom and kitchen
Emergency call system — Could be as simple as a video doorbell or intercom to the main house
Think About Their Daily Routine
What does a typical day look like for your parent? Do they cook? Do they have hobbies? Do they need space for medical equipment or a caregiver to visit?
The design should reflect how they actually live. If your mom loves to cook, a real kitchen matters. If your dad mostly reheats leftovers, a kitchenette might be fine. If they have a caregiver who visits regularly, think about whether there's space for two people to move around comfortably.
Location on the Lot
Where the ADU sits on your property makes a difference. Ideally, it should be close to the main house (so you're nearby if they need help), but not so close that it feels like you're living on top of each other. It should also be positioned so it gets natural light and feels welcoming — not like an afterthought tucked into a dark corner of the yard.
More Than a Building
Designing an ADU for aging parents is as much an emotional decision as a financial one. You want them close and safe while ensuring they still have their independence and dignity. Thoughtful design can make all of that possible.
Let's Create Something That Works for Your Family
At Second Key, we've helped families navigate these exact decisions. A free assessment will help you figure out what's possible — and what design choices make sense for your parent's needs.