The New ADU Law in Massachusetts: What It Means for Senior Homeowners

Massachusetts has just taken a major step toward solving our state’s housing crisis—and senior homeowners may be among the biggest winners.

With the implementation of the Massachusetts Affordable Homes Act in early 2025, most homeowners in single-family zoning districts now have the legal right to build an Accessory Dwelling Unit (ADU) on their property. This new law opens the door to flexible living arrangements, multi-generational housing, and potential rental income – without all the red tape and restrictions that have long made ADUs difficult or impossible to construct in most of the Commonwealth.

As both a real estate broker and attorney, and as someone who has spent nearly 30 years guiding homeowners in Franklin MA and the Greater I-495 region, I want to help you understand what this change could mean for you – especially if you’re over 55 and thinking about your next move.

What Is an ADU and Why Should Seniors Care?

An Accessory Dwelling Unit (ADU) is a smaller, self-contained residential unit located on the same lot as a single-family home. It can be detached, attached, built over a garage, or created inside an existing home – such as in a finished basement or attic.

Under the new ADU Massachusetts law, these units are now allowed by right in most single-family zones. That means:

• No special permits
• No restrictions that limit occupancy to family members
• No automatic bans on rentals

Why is this important for seniors? Because it provides a new and creative way to stay close to family, downsize safely, and unlock the value in your home – without being trapped by the high prices and low inventory that dominate today’s housing market.

Massachusetts Affordable Homes Act: A Closer Look

The Massachusetts Affordable Homes Act, which took effect in February 2025, is a landmark piece of legislation in the Bay State. It encourages housing flexibility by legalizing ADUs across the Commonwealth, provided certain requirements are met:

• ADUs must comply with current building codes, including egress, ceiling height, and safety standards.
• Local zoning boards may require site plan review, especially for detached or external additions.
• If the home is on a septic system, adding an ADU may require a system upgrade.
• Municipalities can still regulate ADUs, but those regulations must not be unreasonably restrictive.

This means while you have the right to build an ADU, you’ll still need to navigate your town’s permitting process – and possibly face resistance from local planning departments. That’s where having the right professional guidance makes all the difference.

Three Powerful ADU Scenarios for Seniors

Here are three common scenarios where the new ADU law can help senior homeowners like you:

1. Move Closer to Family Without Sacrificing Independence

If you’re living in a large home that no longer fits your lifestyle, but you want to stay near your adult children, this law makes that possible. Your child can build an ADU on their property, and you can sell your home and move into the new unit. You’ll be close to family while maintaining your independence.

2. Swap Roles With Your Children

Let’s say your children have outgrown their current home and are looking for more space. You can sell your home to them and have them build an ADU on the same property. You move into the ADU, and they move into your former home. It’s an elegant, affordable solution that keeps the family close and makes good use of existing housing.

3. Support Your Child’s First Home Purchase

If your adult child is struggling to buy their first home, consider adding an ADU to your property. They can live in the ADU while saving for a future purchase—or eventually, the two of you can switch homes as your needs change.

Rental Income for Homeowners

For many seniors, an ADU can provide an additional stream of income. If you’re not planning to use the ADU for family, you can rent it out and use the proceeds to supplement your retirement income or help cover living expenses.

While investors may find it hard to make ADUs profitable—because Massachusetts law doesn’t currently allow for condo conversion of the ADU and main home—homeowners have a big advantage: they already own the land. If you can create a legal, livable ADU for a reasonable cost, rental income can make a lot of sense.

ADU Options and Size Limits in Massachusetts

The new law allows for various types of ADUs, including:

• Detached backyard units
• Attached side additions
• Finished attic apartments
• Basement conversions
• Units over a garage
• Converted barns or garages

However, there are size limitations. An ADU can be no larger than 900 square feet or 50% of the home’s gross floor area—whichever is less. If your home is 1,800 square feet or larger, you can build the full 900 sq ft. Some towns may allow more flexibility.

Advice and Guidance Under the New ADU Law in MA

Determining whether an ADU is feasible for your home isn’t always straightforward. That’s why it’s so important to work with a real estate professional who understands both the law and the market.

As a Senior Real Estate Specialist® (SRES), I’ve been specially trained to guide homeowners over 55 through complex real estate decisions. I also bring my legal background to the table—so I can help you spot potential zoning issues, permitting challenges, and financial risks before you invest time and money.

My process begins with a free ADU consultation where I assess your property, explain your options, and connect you with experienced contractors and professionals if needed. If an ADU is not right for you, I’ll help you explore other options like rightsizing or multigenerational housing.

Let’s Talk About Your Options

If you’re curious whether an ADU in Franklin MA or elsewhere in the Commonwealth is a viable option for you or your family, I encourage you to reach out. This is a real opportunity to create flexibility, preserve independence, and plan ahead for a lifestyle that works better for your current and future needs.

📞 Call or text me at 508-561-6259 to schedule your free ADU consultation.

And when you do, I’ll send you a copy of my Rightsizing Strategy Guide—a practical, Massachusetts-specific resource for homeowners 55+ who are ready to take control of their next chapter.

You can also contact me via the form below – Let’s start the conversation!