Massachusetts ADUs: One Year Later—What Have We Learned?

Last summer, we wrote about Massachusetts' new Accessory Dwelling Unit law and the opportunities it created for

homeowners to add a

smaller, independent living unit to their property. At the time, the big question was simple: Would homeowners actually take advantage of the new law?

One year later, we have an answer: Yes—but building an ADU may not be quite as simple as the new law makes it sound.

The Interest Is Real:

The early numbers are encouraging. According to a recent report examining the first year of the law, Massachusetts communities reported receiving more than 1,600 ADU permit applications and issuing more than 1,200 permits. Those numbers are likely understated because not every municipality responded to the state's survey.

In other words, homeowners are clearly interested.

And it isn't difficult to understand why. An ADU can provide housing for an aging parent, an adult child trying to get established, or a caregiver. It can also create rental income or allow a homeowner to downsize into a smaller unit while remaining on the property.

The Right to Build Doesn’t Mean Easy to Build:

Here's the biggest lesson from year one: the right to build an ADU and the practical ability to build one are two different things.

The state law generally allows one qualifying ADU by right in a single-family zoning district. But homeowners still must navigate building, fire, septic, wetlands, stormwater, energy and other requirements—and those requirements can vary significantly from town to town. A recent statewide review specifically identified these overlapping local requirements and construction costs as major obstacles to ADU development.

For many homeowners, Title 5 remains a particular concern. If an ADU adds bedrooms to a property served by a private septic system, the existing system's capacity needs to be carefully evaluated. Wetlands, setbacks and other site-specific issues can also turn a seemingly straightforward project into a much more complicated one.

Help May Be on the Way:

Recognizing that cost and planning remain significant barriers, Massachusetts has begun rolling out additional ADU resources. The Massachusetts Housing Partnership has developed a statewide program intended to help eligible homeowners evaluate the feasibility of an ADU project. MassHousing has also introduced an ADU construction loan program offering eligible homeowners financing of up to $250,000 for detached ADUs and $150,000 for attached ADUs.

These programs are a good sign that the Commonwealth recognizes the obvious: changing the zoning law was only the first step.

Thinking About an ADU? Start With Due Diligence:

Our advice today is much the same as it was last summer—but perhaps with an extra exclamation point.

Before you hire a contractor or start drawing plans, find out what you’re dealing with. Check your local requirements. Understand your septic capacity. Determine whether wetlands or other land-use restrictions may affect the project. And develop a realistic budget.

The new ADU law has created a real opportunity for Massachusetts homeowners. The first year shows that people are taking advantage of it—but it also shows that good planning on the front end can save a lot of time, money and frustration later.

If you’re considering an ADU, a good place to start is the Commonwealth’s official Accessory Dwelling Units resource page, which provides additional information about the law, regulations and available resources:

Massachusetts Accessory Dwelling Units Information

And, as always, if you’re buying or selling a property with an existing ADU, be sure to raise it with your real estate attorney as early as possible in the transaction.

📞 Have questions? Reach out anytime: www.vanderveen-law.com

***This article is intended for general informational purposes and should not be construed as legal, tax or other professional advice. Prior to acting on any information in this article, you should seek legal, tax or other relevant professional counsel.***