Making Your ADU Accessible: Complete Aging in Place Guide

By Buz Artiano, BuildX | October 2025

When someone asks us about building an ADU for aging parents or adult children with accessibility needs, they always want to know if we can make an ADU accessible without feeling like it's a hospital room. We get it, nobody wants to live in a home that feels like some kind of medical facility. The good news is that there are tons of modern design options that make accessibility features basically invisible when they are done right.

At BuildX, we build ADUs across Massachusetts with accessibility built into every single one from the very start. After building countless ADUs with the purpose of "aging in place" for families on the South Shore and Cape Cod, we've figured out that the best time to add accessibility features is always during construction, not later on or when someone has a fall or an incident.

What Are the Essential Accessibility Features for an ADU?

The accessibility features we always recommend make up five categories that deal with real mobility issues without compromising your dream design.

Covered entryway with zero-step access. At least one entry needs weather protection with decking that is completely flush to the doorway. This lets you put in a ramp later without tearing anything up. We do a covered entry way here to prevent moisture from pooling where the deck meets the door.

Wide interior doorways. Every interior door should be 36 inches wide, or at least 32 inches as the bare minimum. The standard 30-inch doors cause major problems for wheelchairs and other mobility devices.

Accessible bathroom layout. The bathroom needs to have plenty of clearance between the toilet and other items to allow easier transfer from wheelchairs. Roll-in showers with zero-step entry should be installed as standard, not an upgrade.

Blocking throughout walls. We install two-by-eight or two-by-ten boards that go flat against the wall framing at 32 to 36 inches high. This creates a nice solid surface to mount grab bars to anywhere they are needed, without having to try and find the studs.

Natural light and ceiling height. Large windows and nine-foot ceilings can make such a difference in how an accessible space feels. They are for comfort and not code requirements, but they make a big difference in your daily life.

Why Should I Install Blocking for Grab Bars Now?

Blocking solves a problem most people don't think about until later when it's very expensive to fix. Standard wall construction has studs inside that are 16 inches apart, which almost never end up being where grab bars actually need to go. Toggle bolts in sheetrock cannot support someone who is falling, so these are not an option.

We install blocking in bathrooms, hallways, entryways, basement access points, kitchens, and anywhere else that someone might instinctively reach for support. The blocking material runs horizontally behind the sheetrock, giving you solid wood for mounting grab bars anywhere you'd like.

Trust us, this matters. When you call us two years from now needing a grab bar, we can install it in 10 minutes instead of having to open walls and tear things up. We scan every project with Matterport 3D imaging at the stages of framing, mechanicals, and then completion. That scan shows us exactly where the blocking is behind the walls, so we can mount grab bars at the exact height that works for whoever will be using them.

The installation process is very simple. We have that person stand where they will be using the bar, put their hand out naturally, and tape that spot on the wall. So all of our grab bars are mounted at custom height, not the preset heights from a code book.

How Much Do Accessibility Features Cost?

Adding accessibility features during the construction is much cheaper than retrofitting later. Here's what to expect for most projects in Massachusetts.

Just to give you an idea, assisted living in Massachusetts averages $17,000 per month or more for people who need special memory care or skilled nursing. A $7,500 investment during construction is what only two weeks at a facility could cost you. That's a huge difference.

What Shower Options Work Best for Accessibility?

Roll-in showers should be standard in every ADU bathroom we build. We use one-piece acrylic showers from a company out of New York that come with several much needed features.

The shower unit has plywood backing behind the acrylic shell, which lets us install grab bars anywhere. It also gets glued to the floor so you don't have that hollow sound that the cheap fiberglass units have. The entry threshold is about five-eighths of an inch, which is low enough for wheelchair access without causing water pooling issues that the completely curbless designs have.

We include grab bars with every roll-in shower installation, but we wait to do that until you can physically stand in the finished space. Having the person actually put their hand out tells us the right height, we're not going to guess or assume.

Why Should Stairways Be Four Feet Wide?

Standard stairways are three feet wide. By adding an extra foot during the construction, you make sure there is plenty of space for a future chair lift on one side without sacrificing normal foot traffic space.

The cost difference is only about $800 during construction. But if you try to go back and widen the stairway later, it becomes a huge construction job that can cost you $15,000 or more. Wider stairs also make moving furniture easier and makes it feel much roomier.

When Might Universal Design Not Be the Right Approach?

We build every ADU with accessibility features included, but that doesn't absolutely have to be the case.

If you are building a rental unit with no family members who might need accessibility features down the road, you may not want to spend the extra money on them. Standard construction meets all the code requirements, and if you have future tenants with accessibility needs, it's often a situation where they need something very custom, and what you installed may not be right for them anyway.

But also if your property has limited space for the ADU, some accessibility features like five-foot turning radiuses in bathrooms may not even be possible without sacrificing other space you need.

For people who are building ADUs specifically for aging parents or relatives with mobility challenges, it changes things. The small investment that they make at the beginning prevents huge costs later.

Who Benefits Most from Accessible ADU Design?

Most of the people who are considering ADUs fall into 3 categories. Parents moving in with adult children is the biggest one by far. But the exact reversed situation comes in second, where adult children are moving into the ADU to help aging parents. The third category is adult children or relatives with mobility or health needs that require family to be nearby. Rental income is almost never the main reason someone wants to build an ADU.

That means that for almost every situation it makes sense to install all the accessibility features from day one. Maybe the person living there doesn't need grab bars, wide doorways, or roll-in showers today, but needs are always changing, and planning ahead for that will save you thousands down the road.

Ready to Build an ADU That Works for Everyone?

Accessible design does not mean it has to look like a hospital. When done correctly, accessibility features are invisible to visitors, but still provide support for the people who need them. Wider doorways just feel better. Roll-in showers look nice. Grab bars mounted at personal heights blend into bathroom aesthetics.

If you have questions about accessibility features for your ADU project, we are happy to walk through options during a site visit. If you're ready to start the design process, our Massachusetts team can assess your property and discuss how accessible features fit your specific situation.