Do You Need a Real Estate Attorney Before Building an ADU?

By Buz Artiano, BuildX | June 2026

Watch: Bill Sims: What Builders Get Wrong About Real Estate Law | BuildX Podcast #24

You have done the research. You know what an ADU costs, so you have a pretty good idea of where it will be put on your lot, and you are ready to talk to a builder. But most families have a question that bothers them about this time. Do they really need to get an attorney before any of the ADU building starts? It seems like an unnecessary expense, especially when you already have to pay for a project that will cost you six figures. So you are tempted not to do it, to do the paperwork yourself, or wait until something goes wrong. But there is a risk to that.

My name is Buz Artiano, and I am the founder of BuildX. We've built dozens of ADU projects across Massachusetts, mostly around the South Shore and Plymouth County areas. We are the only team you need, we handle design, permitting, and construction. So we see every phase of a project from the first site visit up until you move in. We deal with septic constraints, zoning issues, and the state's new ADU laws. And after years of watching families try to shortcut the legal side, I can tell you this for sure: the attorney conversation should be the first conversation, not the last one.

This article will explain exactly why legal counsel needs to be at the first of your ADU project, what an attorney actually does for you, and what can happen when families skip that step. We will also tell you how to decide if the attorney you are thinking about hiring is the right one for you. If you are building an ADU for an aging parent, paying for it with family money, or putting an ADU structure on property that will have more than one person with a stake in it, getting an attorney isn't optional. It will be the thing that keeps your investment together in the future.

Why Should You Hire an Attorney Before You Hire a Builder?

The best answer is that an ADU is not just a construction project, it is a legal project that involves title, ownership, zoning, estate planning, and sometimes even eligibility for Medicaid. We tell every prospective client the same thing, and that is that you need a team to build an ADU, and that team starts with an attorney who understands trusts, beneficial interests, and the regulations for an ADU.

Most families think all the legal work comes at the end when the building is completed and it's time to close or transfer ownership. But thinking like that creates what is called a deferred liability. So everything looks fine on the first day, but ten years later, when a parent passes away, a family member wants their share, or there is a divorce that divides the property, not having the right legal documents can turn the family project into a courtroom fight.

The attorney's job isn't to slow down your project. The attorney's job is to make sure the ownership, the financing, and the family issues are figured out before you pour the foundation. At BuildX, we tell you plainly that the attorney conversation is the first thing, not the last thing.

What Does a Real Estate Attorney Actually Do for an ADU Project?

A real estate attorney who works on an ADU project deals with several different areas that the builder, surveyor, or even a financial advisor can't. Here is what they actually do.

Title and ownership review. The attorney checks who holds the deed, whether there is a mortgage, and what will happen if the property owner can't pay the mortgage. If a parent is paying for the ADU on a child's property, the attorney figures out how to protect the parent's investment when the parent does not hold title to the land.

Trust and beneficial interest structuring. For families with more than one generation, the attorney might advise you to put the property into a revocable trust with all the beneficial interests spelled out. This gives the parent a legal stake in the property's value, even if it is the child who holds the deed. How much the parent's interest will be can be negotiated and doesn't have to be the same amount as their financial contribution.

Zoning and permitting guidance. Massachusetts lets homeowners build one ADU by right under the Affordable Homes Act. You can review all the rules at mass.gov. But local building code, health code, and dimensional requirements for size still have to be followed at the city level. An attorney who knows the zoning board in your town can tell you whether you will have to have setback variances, special permits, or other local approvals.

Estate planning coordination. If the ADU is for aging parents, the attorney reviews how the way the legal documents are worded will work in the whole estate plan. This includes questions about what happens when the parent passes away, which sibling will inherit and how much, and if it will cause there to be Medicaid look-back issues. Also, the attorney can advise if the deed should be for a joint tenant or a tenants in common situation.

Financing and mortgage review. If the property already has a mortgage, the attorney will review the mortgage paperwork to decide if the ADU construction has to have lender approval, if a new mortgage or HELOC is necessary, and whose name should be on the financing. This is especially important when a parent is putting up the money but the child holds the mortgage.

What Happens When Families Skip the Attorney?

The most common thing that we see is when a daughter owns the main house. Mom sells her home, takes the money, and pays for the ADU to be built on the daughter's property. Mom moves in and everyone is happy. But mom owns nothing because the transfer of property in Massachusetts is always tied to the actual real estate, not the ADU. In legal terms, the ADU is considered an improvement to the daughter's property. Mom has no title, no deed interest, and no legal claim to the ADU even though she paid for it.

Now suppose the daughter gets divorced or she defaults on the mortgage. Or perhaps the daughter and her husband decide they want to sell. The investment that mom put in, which could be $300,000 to $500,000, is for a property she doesn't own. If she doesn't have a trust or a beneficial interest agreement set up, or some other legal document, mom has no way to make any decisions about the ADU.

We have seen this situation enough times to make it a company guideline. Every BuildX client gets the same advice, which is while the building project goes ahead, you need to get guidance on all things that affect your family. The attorney doesn't just protect the investment, they protect the family relationships.

After years of working with families through every part of the ADU process, we estimate that a typical ADU project falls apart for three reasons: about 50 percent are family issues, 25 percent construction decisions, and 25 percent involves permits. This surprises most homeowners, who think that the building process itself is the hardest part. Actually that is the straightforward part. The family relationships, questions about ownership, conversations among siblings, and issues with the estate are the things that cause projects to fall apart most often if they are not dealt with early. That is why we insist on talking to an attorney before the architect. The legal part needs to be done before the first design meeting, because who will own the property affects everything that comes later, from whose name is on the permits to how the ADU is financed to what happens when things change in the family.

How Much Does a Real Estate Attorney Cost for an ADU Project?

The first time you meet with most real estate attorneys who do ADU work is free. We confirm this with the attorney we recommend to our clients. We always check this with the attorneys we recommend to our clients. The first consultation, where the attorney hears your situation and tells you what help you need, costs you nothing. After that first meeting, the attorney will give you a rough estimate of the legal costs based on how much work is involved.

The amount of work varies. To represent a seller on a real estate transaction in town is usually a flat fee. Trust work, planning the estate, going before a zoning board, and dealing with Medicaid issues are charged on an hourly rate. Some things you will have to pay upfront for and some you won't. The attorney can give you a budget once they understand the details of your family, your property, and what BuildX is proposing to build.

The important comparison isn't the attorney's fee compared to no fees. The comparison is the attorney's fee compared to how much it will cost to straighten out a legal mess years later. A difference of opinion on the trust, a sibling buyout, or a foreclosure that comes as a surprise to a parent who paid for the ADU, all those problems cost tens of thousands of dollars and cause serious problems in families. The legal work up front is a fraction of that cost.

What Should You Look for in an ADU Real Estate Attorney?

Not every real estate attorney is able to work with an ADU project because they have to deal with so many legal issues that only apply to an ADU. The attorney you want must have specific experience with trusts and beneficial trusts, as well as zoning and permits for towns in Massachusetts. They also need to be familiar with planning estates when more than one generation is involved and dealing with construction financing.

We tell all of our clients that if you don't like someone on our referral list, go find an attorney who handles these types of cases all the time. You need someone who does this work every day, not someone who has to figure it out as they go. You take the same risk in working with an attorney who dabbles in ADU law as you do working with a builder who dabbles in ADU construction. The things that they miss become your problem.

The red flags to look out for are simple. If the attorney has never set up a trust for a family that is building an ADU, that is a red flag. If the attorney is not familiar with the zoning laws in Massachusetts for ADUs, that is also a red flag. If the attorney can't tell you the difference between joint tenants and tenants in common and why the difference is important for your family, then you should find someone else.

A qualified attorney will also have a list of people he can refer you to for specific things. If you need a Medicaid estate planning specialist, a tax attorney, or a specialist in zoning beyond what they can handle, then the right attorney will help connect you with the right people rather than someone they have not worked with in the past.

Is an Attorney Necessary for Every ADU Project?

Not every ADU project has the same legal issues. If you own your property outright, you are building the ADU for yourself, there are no other family members involved, or problems with the mortgage, and no estate planning, then there won't be much legal work to be done. You might still want to have an attorney review the zoning laws to make sure you are complying, as well as the construction contract, but you won't have any trust work or beneficial interest structuring.

Where the attorney becomes essential is when there is family money involved, when the property has more than one stakeholder, when aging parents are involved, or when the ADU is being financed with a combination of equity, savings, and family contributions. These types of situations can cause legal issues that can't be handled by the builder, financial advisor, or a search engine. Bill Sims, who has practiced real estate law for 42 years, says: don't do it alone. Don't try to piece together answers from the internet. The information you find may not apply to Massachusetts.

Your ADU Team Starts Before the First Shovel

The families who don't have legal problems with their ADU are not luckier than the ones who do, they are just more prepared. They have put together the right team before the project started and they've had difficult talks about ownership, inheritance, and about what happens if circumstances change in the future. They did their work with an attorney who understood what was at stake from the beginning. The first step is not choosing a floor plan. The first step is choosing the team that protects your family and your money for the foreseeable future.