The Grandparent ADU: Why Massachusetts Boomers Are Building to Be Closer to Family

Baby boomers control $19 trillion in housing wealth. A growing number are using it to build ADUs — and it's changing the housing conversation in Massachusetts.

It usually starts with a conversation at the kitchen table. Maybe it's after a holiday visit that felt too short, or after a grandchild's first birthday when the drive home took three hours. A parent turns to their adult child and says: What if we were just… closer?

It's not a hypothetical. According to the National Association of Realtors, the number one reason Americans move is to be closer to family. And in Massachusetts, that conversation is turning into construction permits — in an estimated 900,000 backyards across the Commonwealth.

Since the Affordable Homes Act went into effect in February 2025, homeowners across the state can build an accessory dwelling unit — an ADU — by right on single-family lots. No special permits, no zoning variances. And while the law was designed to address the state's housing crisis broadly, one group is uniquely positioned to act on it: grandparents.

The numbers tell the story

Baby boomers — Americans born between 1946 and 1964 — hold an estimated $19 trillion in real estate wealth, roughly 40% of all housing assets in the U.S. They control about half of the nation's $34.5 trillion in home equity. And with over $85 trillion in total assets, they represent the wealthiest generation in American history.

Most of that wealth is locked in their homes. But unlike previous generations of retirees, today's boomers aren't rushing to sell. They're staying put. Nearly 12,000 Americans turn 65 every day, and the so-called "silver tsunami" of home sales has been more of a slow drip. Boomers aren't looking to downsize into a condo in Florida. They're looking for ways to stay connected to family — on their own terms.

Meanwhile, a Boston University study predicts that 96,000 residents could leave Massachusetts due to housing costs. ADUs offer a way to retain families by creating affordable living options on land that's already owned — no new subdivision required.

An ADU gives them exactly that.

What a "grandparent ADU" actually looks like

The concept is simple. A grandparent builds (or funds) an ADU on their own property or their adult child's property. The result: independent living, a few steps from the people they love most.

In Massachusetts, ADUs under 900 square feet can now be built by right in any single-family zoning district. That means a converted garage, a finished basement apartment, or a new backyard cottage. No special permit required.

Think of it as a triple option hiding in plain sight on properties across the state — like the old school football play where every path leads to a gain. Here's what it looks like in practice:

Scenario 1: Grandparents build on their own lot. They stay in their home and rent or offer the ADU to a family member — or move into the ADU themselves and let their adult child's family use the main house. Either way, the grandkids are steps away.

Scenario 2: Grandparents fund an ADU on their child's property. The adult child may not have the cash or equity to build. But their parents do. A boomer grandparent with $300,000+ in home equity can tap a HELOC to fund a $150,000–$250,000 ADU build on their child's lot. The grandparent gets a place to stay when visiting — or eventually, a place to live.

Scenario 3: Aging in place, with backup. A grandparent builds an ADU as a future caregiver suite. When the time comes, a family member or aide can live on-site. This avoids or delays assisted living, which in Massachusetts averages over $6,000 per month. That's over $72,000 a year — money that could instead go toward everyday essentials, family needs, or simply staying independent longer.

Massachusetts is making it easier

The state isn't just allowing ADUs — it's actively encouraging them. Governor Healey's administration has specifically highlighted the aging-in-place benefits of the new law.

By-right permitting means no special permit hearings, no zoning board approval, and no neighbor veto for ADUs under 900 square feet. The state estimates 8,000 to 10,000 ADUs will be built over the next five years as a result.

No-interest financing is available through state programs for residents building an ADU for people with disabilities or those over 60. That's a direct incentive for the grandparent use case.

The ADU Incentive Program, run through the Massachusetts Housing Partnership, is providing outreach, technical assistance, and financial support to homeowners looking to build. MHP has a long track record of creative housing solutions in the state — dating back decades to programs like its original Homebuyers Club grants.

And the data is already showing momentum. According to the EOHLC's February 2026 survey, 1,224 ADU permits have been approved across 217 Massachusetts towns since the law took effect — with an overall approval rate of 68%.

Why this matters for your family

If you're an adult child in Massachusetts wondering whether your parents would ever consider this — they probably already are. A Freddie Mac survey found that three-quarters of boomer homeowners plan to pass their housing wealth to their children. But only 9% plan to use their home equity to fund retirement. That means there's a massive pool of capital sitting in boomer-owned homes, waiting for a purpose.

An ADU gives that capital a purpose that benefits everyone. The returns go well beyond the personal:

And if you're a grandparent reading this? You already know. The holidays aren't long enough. The FaceTime calls aren't the same. And your equity isn't doing anything sitting in your walls.

Where to start

Check your town's ADU status. Not all 217 towns are moving at the same speed. Some have detailed permit processes in place; others are still figuring it out. Use ADU Pulse's town tracker to see how your town — or your child's town — is handling permits, what the approval rate looks like, and how it compares to neighbors.

Talk to your family first. The best ADU projects start with a kitchen table conversation, not a contractor bid. Figure out whose lot makes more sense, who's funding it, and what the living arrangement looks like.

Understand the costs. Detached ADUs in Massachusetts typically range from $150,000 to $400,000. Attached conversions (basement, garage) can come in between $80,000 and $200,000. ADU Pulse's cost estimator can give you a rough sense based on real permit data.

Save money by building together. You're probably not the only family in your town thinking about this. ADU Pulse's ADU Club groups homeowners by town so you can unlock 15–20% group discounts from vetted builders. When a builder can do five ADUs in the same town instead of one, shared permitting knowledge, bulk materials, and crew efficiency all drive costs down. Join your town's group — it's free, and we'll only reach out when there's a real deal to share.

Explore financing options. HELOCs, FHA 203(k) renovation loans, and the state's no-interest financing program for homeowners over 60 are all worth investigating. Boston's ADU Pilot Program also offers up to $50,000 in grants for income-qualified homeowners.

If you're a builder or contractor, the demand is real and growing. ADU Pulse connects builders with pre-qualified, geographically clustered homeowner leads — not scattered one-offs. Join the builder network to see where interest is building in your region.