Accessory Dwelling Units (ADUs) are becoming increasingly popular in Massachusetts. Maybe you’re a homeowner thinking about adding some extra living space for family or rental income, or perhaps you’re a builder or remodeler looking to tap into this growing market. 

Either way, understanding the laws, costs, and planning associated with ADUs can feel a little overwhelming.

To get clear, reliable information about ADUs, rely on trusted experts who’ve done the research and have experienced the ADU industry firsthand. This way, you feel confident that you’re making the best decisions for your home or business.

Koopman Lumber recently hosted a community event to help clarify what’s new, what’s required, and what’s possible. Watch our Brews & ADUs event below, where professionals share key insights, valuable tips and answers to common questions. Then, keep reading for more guidance and resources to help you take the next step with your ADU project.

Recapping The Event: Meet the Experts

In this recap, we’ve gathered the event’s most valuable insights from a panel of esteemed industry professionals, including:

Jason Linsky

Jason is the Owner of Mason Sky, a trusted general contracting business. Jason is also a local building inspector serving Millbury, Sutton, Auburn, and Northbridge. With hands-on experience in both construction and code enforcement, he offers practical insights into building safe, compliant, and cost-effective ADUs.

Eric Sampson

Eric is Koopman Lumber’s Vice President of Inside Sales, Estimating, and EWP Design. He has years of experience in ADU design and insights into the Massachusetts building industry. 

Glen Travis

Glen is the Owner/Principal at GMT Home Designs. He and his company work predominantly in the design-build model, where they partner with builders and contractors to build dream homes for the Massachusetts community. 

Bill Forte

Bill is the Deputy Building Commissioner in the city of Brockton, Massachusetts. He has been a Certified Building Official in Massachusetts for around 15 years and was a former general contractor and residential homebuilder.

ADU Massachusetts Laws: One Law to Rule Them All Faces Growing Pains

About eight years ago, Massachusetts replaced a patchwork of local ADU rules with a single statewide law. Sounds simpler, right? Well, yes and no.

Eric explains that communities used to have their own zoning bylaws for things like in-law apartments or family suites. Now, they all have to follow the same ADU law. However, sometimes those old local rules clash with the new statewide law, and it creates confusion.

When towns can’t quickly sort it out, the Attorney General’s office steps in. They have 90 days to respond, but because so many communities are involved, it often takes longer.

Bottom line? Patience is key. These rules are in place to protect you and your neighbors, and sometimes that means waiting for the right answers.

The ADU Opportunity: A Huge Opportunity for Housing and Local Builders

Eric points out that the state expects to see about 8,000 to 10,000 new ADUs in the next five years. That’s a significant increase.

Unlike massive housing developments that only big builders can handle, ADUs are small individual projects perfect for local builders, suppliers, and architects. Everyone gets a chance to be part of it.

For homeowners, this means more options. For builders, it’s a growing market with plenty of room to innovate.

To capitalize on this opportunity, smart planning is key. Glen explains that smart planning involves understanding the specific needs of the consumer and ensuring that any added space blends seamlessly with the existing home’s architectural style. 

The goal is to design in a way that makes the addition look like it was always part of the original structure.

ADU Massachusetts Costs: Why Pricing ADUs Isn’t as Simple as It Seems

Homeowners often wonder how much an ADU will cost them.

Here’s the truth: It depends. Eric shares that ADU prices can range widely from under $100 per square foot for basic projects to $700 or more for custom high-end finishes.

Even though an ADU is smaller than a regular house, you still need walls, a roof, plumbing, and wiring. While the smaller size means less empty space, the building parts don’t get much cheaper.

Choosing the right materials and finishes carefully and working with a trusted contractor can make a big difference in your budget.

A Contractor’s Take: What Most Homeowners Miss About ADUs in Massachusetts

Jason mentions that many homeowners don’t realize an ADU is considered a brand-new dwelling unit under the law. That means fire safety rules, zoning setbacks, multiple exits, and utility connections all have to be met. It’s not just slapping on an extra room.

Knowing this upfront can save you headaches and unexpected costs down the road.

Watch Out for Utility Surprises

According to Jason, another thing homeowners don’t always expect is that utilities can get tricky and expensive.

For example, if your new ADU is far from the main house, the electric company might require costly upgrades like new poles or transformers to provide power.

Water and sewer hookups are usually shared with the main house, but if you’re on a septic system, adding an ADU might mean upgrading it to handle more occupants.

Being prepared for these potential costs helps keep your project on budget.

Fire Safety Isn’t Just Paperwork, It’s Serious Business

When adding an ADU to a single-family home, fire sprinkler systems usually aren’t required. On the other hand, if your addition turns your home into a multi-family dwelling, sprinklers might be mandatory throughout the building, which can get pricey.

It’s important to talk to an architect or building professional early on to understand what rules apply to your project.

The Bottom Line: Plan Ahead for a Successful ADU Massachusetts Project

Adding an ADU can be a fantastic way to increase your property’s value, provide housing for loved ones, or earn rental income. However, it takes more than good intentions. You need to follow the rules, understand costs, and plan carefully.

Work with reliable professionals who know the code, zoning, and utilities, and be sure to ask questions early and often. Here at Koopman Lumber, we are happy to work with professionals and homeowners alike to help bring ADU visions to life. With our experience and guidance, your ADU project can be a success that adds value, comfort, and pride to a property for years to come. Contact our team to start tackling your ADU project today.