Do You Need Additional Insurance For Your ADU in Massachusetts?


Carlos Vargas | Jan 29 2026 10:00

What is an ADU — and does your homeowners policy cover it?
If you’ve added a backyard cottage, in-law suite, garage apartment, or another type of accessory dwelling unit (ADU) to your Massachusetts property, you may be wondering what type of insurance protection it needs.

Will your standard homeowners policy extend to your ADU — or do you need a separate policy entirely?
ADUs are increasingly popular across Massachusetts as more families create multi-generational spaces or explore rental income options. But insuring them properly can be complex — and the wrong assumption could leave you dangerously underinsured.

Here’s what you need to know:
In this article, we’ll break down what an ADU is, how insurance typically applies, and the steps you should take to ensure your property — and everyone on it — is protected.

What is an ADU?

An accessory dwelling unit (ADU) is a secondary living space located on your property that has its own kitchen, bathroom, and sleeping area. Common ADU types include:

  • A finished basement or attic apartment
  • A garage conversion
  • A detached guest house or backyard cottage
  • A newly built stand-alone unit

With recent zoning updates across Massachusetts, ADUs are becoming more accessible — but whether yours is rented out, occupied by family, or empty most of the year, it must be reviewed for proper insurance coverage.

Does Your Homeowners Policy Automatically Cover an ADU?

Not necessarily. Most standard homeowners policies are designed for single-family homes, not multi-unit living or rental structures.

Your ADU’s coverage depends on several key factors:

  • Attached vs. Detached: A detached ADU may fall under “Other Structures” coverage — typically limited to 10% of your dwelling limit. That’s often far too low to rebuild a fully finished ADU.
  • Rental Use: Renting the ADU (short- or long-term) may require a landlord policy that covers liability, property, and loss of rental income.
  • Family Occupancy: Even if a family member lives there, the ADU still represents an additional household on your property — something that must be disclosed for accurate coverage.

Common Gaps in ADU Coverage

Here are some of the most frequent issues we see when homeowners assume their ADU is automatically included:

  • Underinsured structures: “Other Structures” limits rarely match the rebuild cost of a fully finished ADU.
  • Liability gaps: Injuries inside or around an undeclared ADU may not be covered — especially if renting to tenants.
  • Loss of rental income: If your ADU generates income, a standard homeowners policy usually won’t reimburse rental losses after a covered claim without added protection.

What Should You Do if You Have (or Plan to Build) an ADU?

Whether you’ve already built one or are in the planning stage, follow these steps:

  1. Call your insurance agent early. Before construction or conversion, let us review how your policy should be structured.
  2. Determine the rebuild cost. Get an updated value so we can confirm whether your current Other Structures limit is sufficient.
  3. Clarify how the ADU will be used. Family residence? Long-term tenant? Short-term rental? Each requires a different coverage approach.
  4. Never rely on assumptions. Builders and contractors often misunderstand insurance requirements — always confirm with your insurance professional.

Make Sure You’re Covered, Not Just Comfortable

At Vargas & Vargas Insurance, we’ve seen how assumptions about ADU coverage can create costly gaps — especially when claims occur. As Massachusetts insurance specialists, we’re here to help you protect every square foot of your property, including new or updated living spaces.

Have questions about insuring an ADU or recent updates to your home?
Let’s make sure your coverage keeps up with your lifestyle — not just your original homeowners policy.

Call us today at (617) 298-0655 or email customerservice@vargasinsurance.com for a complimentary policy review.