Who Owns the Cottage When Mom Is Gone? Why a Family ADU Needs an Attorney Before It Needs a Builder

The parents sell the house they raised their children in, hand their daughter $180,000 from the proceeds, and move into the new cottage behind her house. Everyone is happy, and nobody writes anything down, because writing it down would feel like planning for something to go wrong. Four years later the father dies. The mother needs more care than the family can give. The daughter's marriage ends, and her husband's attorney lists the cottage as a marital asset built with marital labor on marital land. The son in Arizona asks, reasonably, where his share of the $180,000 went. The cottage is still standing. The family is not. Every one of those outcomes was foreseeable, and every one of them had a one-page answer that an attorney could have put in place before the foundation was poured.

The Building Is the Easy Part. The Agreement Is the Project.

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Builders, lenders, and designers are good at their jobs, and none of their jobs includes asking who will own the cottage in fifteen years. The general contractor builds what the drawings show. The lender underwrites the borrower on the deed. The building inspector confirms the structure complies. At no point in that pipeline does anyone ask the parent whether the money was a gift or a loan, ask the homeowner whether a sibling was promised anything, or ask either of them what happens if one of them cannot make decisions anymore.

That silence is not negligence. It is scope. Those are legal questions, and the only professional licensed to answer them is an attorney. The ADU Exchange's position is simple: on a family ADU, the attorney is not an optional add-on near closing. The attorney is the first professional in the room, because every other professional's work depends on answers only the attorney can produce.

This article is about the questions. For the four ways families structure ownership, read the companion guide on whose name goes on the deed. For what Medicaid can do to a parent's contribution, read the guide on the five year look-back. This piece covers the ground between them: the agreement itself.

Five Events the Family Did Not Plan For

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Every family ADU will eventually meet at least one of these. A good attorney drafts for all five at once, because the documents that handle them overlap, and because the cost of drafting for five is barely more than the cost of drafting for one.

The Money Has to Be Called Something

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When a parent puts money into a child's property, the law does not accept "it was for the cottage" as a category. The money is a gift, a loan, a purchase of an ownership interest, prepaid rent, or compensation for care. Each one has different tax consequences, different treatment in the parent's estate, and different exposure under the Medicaid rules. The attorney's first job is to pick one with the family and document it.

If it is a gift

For 2026, the federal annual gift tax exclusion is $19,000 per recipient, or $38,000 when a married couple splits a gift, and the lifetime gift and estate exemption is $15 million per person. A $180,000 contribution is well over the annual exclusion, which means a federal gift tax return is due the following April even though no tax is owed. Families skip that return constantly, and the omission surfaces years later in an estate administration or a Medicaid application. The attorney and the family's accountant make sure the return is filed and the lifetime exemption is tracked.

The federal number is not the one most New England families need to worry about. Massachusetts imposes its own estate tax on estates above $2 million, a threshold the Legislature set in 2023, and that threshold is reached by ordinary families with a paid-off house and retirement savings. A gift that moves value out of a parent's estate can help with that. A gift that is later unwound, or that was really a loan, can hurt. Which one it is depends on what was written down at the time.

If it is a loan

A loan needs a promissory note with a real interest rate, a repayment schedule, and ideally a recorded mortgage against the child's property. Without those, the IRS can treat it as a gift, a divorce court can treat it as marital property, and a Medicaid caseworker can treat it as a transfer for less than fair value. With them, the parent has a secured asset that survives every event in the table above.

If it buys an ownership interest

The parent goes on the deed, with everything that follows: exposure to the child's creditors and the child's divorce, a change to the homestead declaration, a possible due-on-sale question with the existing mortgage, and a share that passes through the parent's estate. Sometimes it is the right answer. It is never the default answer, and the deed guide walks through the alternatives.

If it is compensation for care

When the arrangement includes a child providing care, a written caregiver agreement that sets out the services and the compensation is what distinguishes legitimate payment from a disguised gift. Massachusetts elder law attorneys draft these routinely. Without one, every dollar that moved from parent to child in the five years before a MassHealth application is presumed to be a transfer that triggers a penalty period.

Your Parents Can Be Your Tenants

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This is the part that surprises families most. A parent living in a separate dwelling unit on a child's property, with their own door and their own kitchen, can acquire the legal status of a tenant whether or not rent changes hands. In Massachusetts, residential tenancies are governed by M.G.L. c. 186, and removal of an occupant goes through summary process under M.G.L. c. 239. There is no family exception. The daughter who needs to move her mother to memory care against her mother's wishes, or the son who needs the unit back after a parent's death to house his own family while a sibling objects, may find that the legal route runs through Housing Court.

None of that is a reason not to build. It is a reason to write an occupancy agreement before anyone moves in. A good one answers the questions a landlord and tenant would answer, in language a family can live with:

• Who has the right to occupy the unit, and is the right personal to the parent or does it extend to a surviving spouse, a caregiver, or a future partner?
• What does the occupant pay, if anything, and which utilities and maintenance belong to whom?
• What happens if the occupant can no longer live safely alone? Who decides, and on what basis?
• What notice does either side give, and what is the process if the family cannot agree?
• What happens to the unit, and to any money the parent contributed, when the parent moves out or dies?

One more thing to settle in the same document: whether the family ever intends to rent the unit to someone outside the family. The Massachusetts statewide ADU framework bars municipalities from requiring owner occupancy, but it leaves short-term rental regulation to the town, and the moment a stranger becomes the occupant, the full body of landlord-tenant law arrives: security deposit rules, lead paint obligations when a child under six moves in, and habitability standards under the State Sanitary Code. Rental is a legitimate future for many family ADUs. It should be a decision the family makes with counsel, not something it drifts into.

What Is Already on the Title

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Before the family changes anything, the attorney reads what is already there. Three items catch families off guard.

The mortgage

Nearly every residential mortgage contains a due-on-sale clause, and many contain covenants about alterations to the property and about who may be added to title. Adding a parent to the deed, recording a life estate, or placing a second lien in favor of the parent can each require lender consent. The attorney reads the note and the mortgage and tells the family what needs permission before it is done, rather than after a lender's attorney finds it.

The homestead

Massachusetts homestead protection under M.G.L. c. 188 shields a home from certain creditor claims, and the protection depends on who owns the property and who occupies it as a principal residence. Adding an owner, creating a life estate, or having a parent occupy a separate unit all raise the question of whether the existing declaration still does its job. An elderly or disabled owner may also qualify for an enhanced homestead. This is a recording-office task that takes an attorney minutes and that families almost never think of.

Easements, restrictions, and the lot itself

Recorded easements, deed restrictions, homeowner association covenants, septic covenants, and conservation restrictions can limit where a unit may be built or whether it may be occupied by someone other than the owner. The attorney pulls the chain of title; the surveyor confirms where the lines and the easements actually fall on the ground. On a family build, do both before the design, for the reasons laid out in the survey guide.

Siblings, Fairness, and the Will

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The quiet casualty of most family ADU disputes is a sibling who was not in the room. A parent contributes $180,000 to one child's property. The parent's will, written a decade earlier, divides everything equally. On the parent's death, the child with the ADU has a house that is worth more, and the other children have an estate that is $180,000 smaller. Whether the parent intended that outcome is irrelevant; what matters is whether the parent's estate plan says so.

The attorney's answer is an equalization provision, a specific statement in the parent's will or trust that the ADU contribution is an advancement against the recipient's share, or a gift that is not to be equalized, or a loan to be repaid to the estate. Any of the three is fine. Silence is what creates the lawsuit. The same meeting should update beneficiary designations, confirm the health care proxy and durable power of attorney, and, where a trust is the right ownership vehicle, settle who the trustee is and what the trust says about the unit.

For the homeowner child, the estate plan needs updating too. If the child dies first, the parent's right to stay must survive the child's estate and the child's surviving spouse. That is a sentence in a will or a recorded instrument. It is a crisis if nobody wrote it.

The Contractor Contract Is a Legal Document Too

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Families who have never hired a contractor for anything larger than a bathroom are about to sign the biggest construction contract of their lives, often with a parent's money. In Massachusetts the Home Improvement Contractor law, M.G.L. c. 142A, requires a written contract for residential work over $1,000, requires the contractor to be registered, caps the deposit at one third of the contract price except for special-order materials, and gives homeowners access to a guaranty fund and an arbitration program when things go wrong, but only if the contractor was registered and the contract was in order. Before the family signs, an attorney should read it. Thirty minutes of review catches the missing registration number, the deposit over the cap, the vague scope, the absent completion date, and the change-order clause that lets the price float. For the longer version, read what California's ADU fraud wave should teach New England.

One Family, Two Attorneys

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Parents and children in an ADU arrangement have interests that overlap and interests that conflict, and the rules of professional conduct are clear that one attorney cannot represent both sides of a transaction where their interests diverge without informed consent from everyone. In practice, the cleanest arrangement is one attorney for the homeowner and a separate attorney, often an elder law attorney, for the parent. It costs more than one attorney. It costs far less than one attorney whose work is later unwound because a court found the parent had no independent advice.

The Same Questions in All Six States

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Everything above is framed around Massachusetts because that is where most of our readers build, and because the Massachusetts statewide ADU framework has brought these arrangements to the surface faster than anywhere else in the region. The questions are the same in Rhode Island, Connecticut, New Hampshire, Vermont, and Maine. The answers are not.

• Estate tax. Massachusetts, Rhode Island, Connecticut, Maine, and Vermont each levy a state estate tax with its own threshold and its own rules. New Hampshire has none. A contribution that is estate-neutral in one state can create or avoid a tax in another, and the attorney must run the numbers in the state where the parent is domiciled, which may not be the state where the ADU sits.
• Medicaid. MassHealth, Rhode Island Medicaid, HUSKY in Connecticut, and the programs in the three northern states each apply the federal five-year look-back with their own asset rules, penalty divisors, and treatment of life estates and caregiver agreements. Elder law is state-specific; hire counsel licensed where the parent lives.
• Landlord-tenant and homestead. Every state has a tenancy statute, a summary process procedure, and some form of homestead protection, and no two match. The occupancy agreement and the title work must be drafted for the state where the property sits.
• ADU law itself. Owner-occupancy rules, rental restrictions, and whether a unit may ever be conveyed separately differ by state and by town. Confirm the current rule before the family builds a plan on it.

The Order of Operations

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Here is the sequence The ADU Exchange recommends. Steps can be combined in one or two meetings; what matters is that none of them happens after the design is locked.

1. Hold the family meeting with everyone, including the siblings who are not moving in. Put the money, the expectations, and the fears on the table. Write down what was said.
2. Engage the attorney, or the two attorneys, before any design work. Bring the deed, the mortgage, the parents' existing estate documents, and the written notes from the family meeting.
3. Choose the ownership structure. Joint ownership, a recorded lien, a life estate, or a trust, with the tradeoffs the deed guide lays out, matched to the family's goals and the lender's requirements.
4. Paper the money. Gift letter and gift tax return, or promissory note and recorded mortgage, or purchase documents, or caregiver agreement. One of them, chosen on purpose.
5. Sign the occupancy agreement before anyone moves in, with the five events built into it.
6. Update both generations' estate plans: wills or trusts with equalization language, health care proxies, durable powers of attorney, and beneficiary designations.
7. Review the title work: lender consent where needed, a refreshed homestead declaration, and a survey that confirms what the easements and restrictions mean on the ground.
8. Have the attorney review the construction contract before the deposit leaves the parent's account.
9. Revisit the documents at every life event: a death, a diagnosis, a marriage, a divorce, a sale, a move. The paperwork is a living plan, not a one-time filing.

What to Bring to the First Meeting

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An attorney can do a great deal in one hour if the family arrives prepared. Bring:

• The current deed and the most recent mortgage statement for the property where the ADU will be built.
• Any existing wills, trusts, health care proxies, and powers of attorney for both generations, even if they are old.
• A plain statement of where the money is coming from, how much, and what the family currently believes it is.
• The names of everyone who might have an expectation: spouses, siblings, step-relatives, and anyone who has been promised anything.
• The feasibility result and the municipal checklist, so the attorney knows what the town will require and whether rental is on the table.
• The contractor proposal, if one exists, and any deposit already requested.

Why This Comes Before the Builder

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A family ADU is one of the most generous things one generation can do for another. It is also the single largest financial decision many of these families will make together, and it is made at exactly the moment when the people involved are least inclined to think about how it ends. The attorney's role is to think about that for them, early, so the cottage can be what it was meant to be: a home for the people who built it, and not a dispute for the people they leave behind.

The ADU Exchange connects families with attorneys across New England through the Court House department. Start there, before the drawings.