Where Should Accessibility Blocking Be Installed in Your Massachusetts ADU?

By Buz Artiano, BuildX | February 2026

When we install blocking in an ADU, we have to think about every time someone might need to reach out for a support grab. Not just in the obvious places. Think about the hallway when you are carrying groceries. Or the back door when your hands are full. Even the kitchen when you have been standing too long and need a rest.

Most builders focus only on the bathroom. They install one grab bar, call it accessible, and then move on. But anyone who has helped a parent or family member in their home in real life knows that is nowhere near adequate. You need support in the places where you spend time and live your life.

At BuildX, after building dozens of ADUs across Massachusetts, we always keep one very important principle in mind: future-proof everything. We put blocking throughout the whole ADU so that years from now, when you call us and say you need grab bars installed, we can put them anywhere you need in the home and it only takes about 10 minutes. No exaggeration, just ten minutes, because the blocking is already there behind the walls.

Where Does Blocking Need to Go?

Installing blocking during construction typically adds $200 to $500 to your total cost, depending on the size of the ADU and number of rooms. Adding it after the drywall is up costs $500 to $1,500 per spot because you would have to do a lot of cutting, patching, and repainting of the walls. Which is exactly why we include blocking everywhere from the start.

The bathroom is probably the most important, but blocking really needs to go in every room where someone might need a little extra support. Here is where we install it in every BuildX ADU:

Bathrooms: Both bathrooms get blocking on every wall. Around the toilet, along the shower walls, beside the vanity. There's no reason to guess where someone will need support. We just make sure they can put a grab bar anywhere it might be needed.

Hallways: Every hallway gets continuous blocking along at least one wall. When you are walking through the house, especially at night or when you are tired, having a hand rail that is solid to reach for makes a huge difference.

Entryways: The main entrance and back door both need blocking. When you are coming in from the back door, especially if you are carrying something or coming up from the yard, you will always need a good support rail to be available to you.

Basement access: If there is a door to basement stairs or a utility area, blocking goes on both sides of that entrance because moving from room to room is when falls happen the most.

Kitchen: Along areas where someone might need to stand for long periods of time. Such as next to the stove, beside the sink, and along the counters.

Bedrooms: Very important in the main bedroom. Especially important to have near the bed, on the way to the bathroom, or beside the closet.

The rule we follow is simple: if you find yourself walking into a space and putting your hand out like you want to grab something, that spot needs blocking.

What Is Blocking and Why Does It Matter?

Blocking is horizontal wood installed inside the wall that is designed to support grab bars and handrails. Wall studs are normally spaced 16 inches apart, which means a grab bar might be needed where it will land between studs with nothing solid to attach to.

We use two-by-eight or two-by-ten lumber installed flat, set at 32 to 36 inches high depending on the situation. The blocking runs in long lengths so that a grab bar can be installed anywhere along the wall, not just where the studs are.

If there is no blocking installed, grab bars get attached with toggle bolts into drywall, which is very dangerous. If someone is actually falling and grabs onto a bar installed this way, it will rip it right out of the wall. Now not only is the person still falling, but they also have a big piece of metal coming down with them. We have seen what results from this and it is absolutely not worth the risk.

How Do You Know Where Blocking Is Later?

We use software called Matterport to scan every property once the framing is complete, before the drywall goes up. This gives us a 3D record of exactly where all the blocking is installed.

Two years from now, you can call us and say you are ready for a grab bar, and all we do is pull up the scan. We can see behind the walls to show you exactly where the blocking is and ask where you want the bar. Then we have you put your hand out so we can see what height to install it. The bar gets installed at exactly the right spot for you, and the whole process takes about ten minutes because we know exactly where the solid backing is.

The Matterport scan also shows wire locations, plumbing, and anything else in the walls. If you ever want to mount a TV, install a medicine cabinet, or add shelving, we can tell you exactly what is behind that section of drywall with our handy scan.

Why Install Blocking Now Instead of Adding Grab Bars Later?

Blocking costs almost nothing if you install it during construction. It's only a few extra pieces of lumber and a few extra minutes of labor. Once the drywall is up, adding the blocking later for a grab bar means cutting into the wall, installing it, patching the drywall, and repainting. That turns a ten-minute installation into a half-day project.

We don't have to install the grab bars on day one. We just need the blocking in place so that when the time comes, adding them becomes very simple. The blocking sits there behind the drywall, invisible, waiting. You might not need a grab bar for years, but either way, you are ready.

How Are Grab Bars Positioned for Each Person?

Grab bar placement is fully custom to your needs. What works for one person does not work for another. Height, angle, and location all depend on the person who will be using them.

When it is time to install grab bars, we come over and have the person go into the space and move around naturally. Do things like walk in and out of the shower, sit down and stand up from the toilet, and reach out where they would naturally reach. We watch where their hands go, then mark those spots.

Sometimes grab bars go at an angle. Sometimes we use L-shaped bars that provide both vertical and horizontal grip. The vertical part gives you something to grab when stepping in, and the horizontal part is great once you are already standing. You have more grip strength pulling vertically than horizontally, so doing it this way usually works better than just a single straight bar.

Because we have blocking everywhere, we can put the bar exactly where it makes sense for that specific person. No compromises based on stud locations.

What About Shower Enclosures?

The one-piece shower units we install come with three-quarter-inch Baltic plywood bonded to the fiberglass on all sides and the back. Because of the way the plywood is actually molded to the unit, you can put a grab bar anywhere because there is solid backing already built in.

The grab bars we install are so solid we can do pull-ups on them. When someone actually needs to grab one, they will not pull anything out of the wall, the installation holds strong.

For finishes, we pretty much always stick with white and brushed nickel. Black looks good on day one, but soap scum shows up almost immediately and you will be cleaning constantly in order to make them look nice. White and nickel stay looking clean without extra work.

Is Blocking Right for Every ADU?

Blocking comes standard in every BuildX ADU, but that doesn't mean it's always necessary. The truth is if you are building a short-term rental unit where accessibility is not a priority, and you are certain that your ADU will not house someone with mobility issues down the road, blocking may be excessive for your situation.

That being said, we have yet to meet a homeowner who regretted having blocking installed. The cost during construction is next to nothing, and circumstances can always change. The parent who visits occasionally today might move in next year. A healthy 55-year-old might need a knee replacement at 60 and have problems getting around for a while. Blocking is insurance that costs almost nothing.

Does Blocking Add Significant Cost?

Blocking during construction adds minimal cost. The wood itself is inexpensive, and the labor to install it during construction is not even worth calculating. Compared to the cost of going back and installing it later, or worse, dealing with an injury from a grab bar mounted with those bolts we talked about, the investment is very small and so worth it.

Every BuildX ADU includes blocking as standard. We do not treat it as an upgrade or an optional add-on. It's just part of how we build because it's the right way to do things.

Ready to Future-Proof Your ADU with Proper Blocking?

Blocking is a construction decision, not one to make after the fact. It happens at framing, long before we get to choosing cabinets or paint colors. That is why we include it in every project from the start.

If you are starting to speak with ADU builders, always ask about blocking. Ask where they install it, what material they use, and how they document the locations. If the answer is just in the bathroom or wherever the grab bars go, they are not thinking about the future.

Want to learn more about aging-in-place features for ADUs? Download our accessibility planning checklist to see everything we include as standard.