What Can Massachusetts Homeowners DIY to Save Money on an ADU?

By Buz Artiano, BuildX | February 2026

We never discourage anyone from doing their own work, DIY stuff can be great, but we have watched so many homeowners start a DIY ADU project with excitement and enthusiasm and then call us three weekends later saying it is too much and they are overwhelmed. Nine hundred square feet of flooring sounds like a manageable task until you have been on your knees for 15 hours and you're not even halfway done.

It is important to save money, especially nowadays, so we understand. An ADU is a no small investment, and cutting costs where you can feels like the responsible thing to do. The real question is not whether you can do some work yourself. The real question is whether the savings justify the time, the risk, and headaches.

At BuildX, we have built dozens of ADUs across Massachusetts, and we have had this conversation countless times. Some homeowners really do save money by handling certain things on their own. Other people spend months on work that would have taken our crews days, only to find out they didn't really save that much money. Here is what actually works and what typically backfires.

Which DIY Tasks Actually Save Money?

If you are going to do anything yourself, flooring and painting are what we recommend to save the most money with the least headache. Installing your own flooring and handling interior painting can save you around $5,000 in labor.

That being said, we have had homeowners commit to installing their own flooring only to realize what 900 square feet actually means. One couple in Plymouth wanted to do all their interior finish work themselves. The wife insisted her husband could handle it, but one weekend in, they called and asked us to take over because it was just too much. Once they were actually doing it, they started to see how much work it really was.

If you are skilled in one particular trade, then that is a great conversation to have. A homeowner who installs flooring professionally is different from someone who watched a YouTube video. But just know that you are only saving the labor portion. You still need to buy the flooring, the paint, the materials. The savings are real, they are just often much smaller than people expect.

What Can You Provide Without Doing the Work Yourself?

The easiest way to keep costs down is by providing items that we install for you. No labor on your part, but you choose the products and prices.

Appliances: We don't supply appliances. You buy whatever appliances you want and we just install them. This includes refrigerator, stove, dishwasher, washer, dryer, and anything else. We stopped doing appliance allowances because everyone either thought the allowance was too cheap or too generous. So now you pick exactly what you want, it works much better this way.

Shower doors: Are not included in our standard package because they start at $850 and go up from there, and a lot of people choose to use shower curtains instead. If you want a shower door, we connect you with our shower door vendors so you meet them on site, choose what you want, and then we just supervise the installation.

Accessories and finishes: TV mounts, TVs, window shades, mirrors, towel bars, robe hooks, toilet paper holders and whatever else you'd like to bring us, we install for you. We walk through with you, put tape on the wall wherever you want things, and our crew hangs everything before you move in. Our goal is that when you walk through on move-in day, there is no work left for you to do.

What DIY Approaches Typically Backfire?

The problems usually start when homeowners try to become their own general contractor or bring outside vendors onto the job site.

Bringing your own subcontractors: The problem here is that we can't warranty work we did not do or supervise, and we can't manage the schedule around unknown trades. When a homeowner brings in a friend who is a plumber or a family member who does electrical work on the side, we lose the ability to coordinate the project effectively. If that work causes problems later, there's nothing we can do about it.

Subcontractors charge you more: A lot of people don't know this. When a subcontractor works for a homeowner instead of an established builder, the usual rate is 20% more. They don't know you and they don't know if the job will be ready when they show up. So they want to make sure they are getting paid. That extra 20% eats into any savings you thought you were getting.

Taking over part of the build: We only do complete projects. We have had people ask us to just do the foundation, then they will take over from there, but we don't do things that way. The coordination, liability, and quality control issues make partial builds impractical for everyone involved.

We are not saying this to keep you dependent on us. We tell you this because we have been doing this a long time and have watched it happen over and over again. Homeowners who bring their own subs almost always end up paying more, waiting longer, and not knowing who to call when something goes wrong. The math rarely works out the way people hope.

How Much Will You Actually Save?

Interior finish work, if you did all of it yourself, might save around $20,000 in subcontractor labor. But you still have to buy the cabinets, the paint, the flooring, and the fixtures. Materials can often be more expensive when buying them as a consumer and not a contractor.

The time investment is the biggest thing. Do you want to spend six to seven months building this, or do you want it done in 100 to 110 days? If you have 20 hours a week to spend on construction, it might be worth it to you, but most people don't have that kind of extra time.

People sometimes think they are going to save $100,000 by doing things cheaper. The reality is closer to $10,000 or $15,000 in actual savings, and if you end up cutting corners and using cheaper low quality products to get to that savings, you will regret it for the next 30 years. The house is a long-term investment. Cutting corners in construction does not pay off the way you might think it does.

Are There Other Ways to Reduce Costs Without DIY?

You can find bigger savings in site conditions rather than labor.

If your property allows you to tap into the existing water service instead of running a new connection to the street, that takes a decent chunk out of the cost. Connection fees and trenching add up fast, so using existing infrastructure where possible makes a difference.

Skipping the shower door and just putting up a curtain saves a few hundred dollars per bathroom. Some people prefer the look and feel of curtains anyway. You can also add the door later once you are actually living in the space and have a better sense of what you want.

Post-construction additions like decks can be done by family members after we are finished. If someone you know builds decks, there is no reason for us to do it. We build to the point where you have a finished, livable ADU, and whatever you want to add afterward is your call, as we are not responsible for warranty on post-additions.

If you are still early in the process and want to understand what your specific property might cost before deciding what to take on yourself, our site evaluations give you that clarity.

Making the DIY Decision for Your ADU

The DIY question comes down to this: Are you actually skilled at the trade, or do you just think you could figure it out? You must have weeks of time to dedicate, it can't be done in a few weekends. Doing your own flooring and painting works for some people and can save you a little money, so does providing your own appliances. But trying to be your own general contractor creates problems that cost more than they save.

Want to discuss which tasks make sense for your situation? Schedule a consultation with BuildX to review your ADU project and identify where your involvement could actually save money without derailing the timeline.