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Welcome to Your Dream ADU by Cozy Nest Creators

Massachusetts Accessory Dwelilng Unit (ADU)

By Buz Artiano, CEO of Cozy Nest Creators

Cozy Nest Creators: Your Guide to Building an Accessory Dwelling Unit (ADU) in Massachusetts

A Bay Staters Guide To Building Their 1st Accessory Dwelling Unit, (also known as an ADU or Secondary Suite or In-Law Apartment)


Cozy Nest Creators has composed a comprehensive guide for Massachusetts homeowners interested in building an Accessory Dwelling Unit (ADU) on their property. This guide covers various aspects of ADU construction, including the definition of an ADU, recent changes in Massachusetts laws that make it easier for homeowners to build ADUs, determining if an ADU will t in your backyard, pro tips for first-time builders, cost considerations, choosing the right contractor, exploring ADU plans and designs, building codes and regulations, rental opportunities, and the importance of energy efficiency and environmental impact.

This guide emphasizes the benefits of building an ADU, such as providing extra living space for family members, generating rental income, and increasing property value. It also highlights the importance of working with experienced professionals who specialize in ADU construction to ensure compliance with local zoning laws and building codes. Additionally, the guide encourages homeowners to prioritize energy efficiency and eco-friendly materials to create a sustainable and cost-effective living space. With this comprehensive guide, Cozy Nest Creators aims to help Massachusetts homeowners navigate the process of building an ADU from start to finish.

What Is An Accessory Dwelling Unit?

ADUs offer a wide range of benefits, but did you know that they can also increase the value of your property?

Hi there from Massachusetts! If you own your home and want to find a way to truly use your property to its full potential, then maybe you have heard of or even looked into an ADU (“Accessory Dwelling Unit”). Let me explain what an ADU really is.

Simply put, it is a second building or space on your property. Examples would be a guest house, granny flat, mother-in-law quarters, or apartment. It can either be attached to the main house or a totally separate structure.

ADUs usually include the same basic rooms you would find in an apartment – bedroom, bathroom, kitchen, and living area. The size can range from a small studio unit, up to a spacious two-bedroom. Keep in mind, that the size of the ADUs will be dependent on the size of your property and the local zoning laws.

ADUs are popular because they are very versatile and can serve many purposes. Here are just a few:

      • A small comfortable home for elderly parents that is close and convenient
      • A long-term or short-term rental that provides a source of extra income
      • An office or studio
      • Or a comfortable, private space whenever you have guests.

ADUs clearly offer a wide range of benefits, but did you know that they can also increase the value of your property, while at the same time helping with the Massachusetts housing shortage?

Now that you understand ADUs a little better, let’s talk about the recent changes in Massachusetts laws that are making it easier for homeowners to build an ADU on their property.

ADUs usually include the same basic rooms you would find in an apartment – bedroom, bathroom, kitchen, and living area.

Learn More: Call ADU Contractor Cozy Nest Creators (781) 745-0000

Affordable Homes Act

Not only did this act remove the zoning restriction, it provided financial incentives for homeowners who want to build ADUs.

Healey Driscoll Affordable Homes Act

In January 2021, Governor Healey signed the Healey Driscoll Affordable Homes Act. Which was a huge step forward in dealing with our state’s housing crisis. This new Act includes several provisions that make it easier and more affordable for homeowners to build these ADUs on their property.

One of the main components of the act is to remove a lot of the zoning laws that prohibit ADU construction. Before this, there were many cities and towns that were unable to build ADUs because of the overly strict zoning laws. The new act requires cities and counties to allow ADUs “by right”(which means no special permit processes are required anymore) in single-family residential zones.

It also establishes a specific definition of ADUs, making the new laws more consistent throughout the state. By definition, an ADU is a self-contained housing unit with a separate entrance, kitchen, and bathroom, located on the same lot as a single-family dwelling.

Not only did this act remove the zoning restriction, it provided financial incentives for homeowners who want to build ADUs. It put into place a new loan program by MassHousing that offers low-interest loans to homeowners for the purpose of ADU construction. These are great loans because they can actually cover up to 100% of the cost of construction and have easy payment options as well. It is now easier than ever for homeowners to finance their ADU projects.

Now that you understand ADUs a little better, let’s talk about the recent changes in Massachusetts laws that are making it easier for homeowners to build an ADU on their property.

Furthermore, the act put in place a grant program to help low- and moderate-income homeowners cover all the costs of their ADU project, from design to construction. This program is extremely beneficial for those who may not have the upfront cash to build an ADU, but would greatly benefit from having one, either for extra income or an extra living space.

Since The Healey Driscoll Affordable Homes Act passed, Massachusetts homeowners now have so many more opportunities to be able to build ADUs on their property. By taking away building restrictions and offering financial assistance to many, this act has really paved the way for the construction of many new ADUs in the Bay State.

In the next section, we will discuss how to determine if an ADU will t on your property and things to think about when you are planning your project.

Photo courtesy Office of Massachusetts Governor Maura Healey

Questions: Call Accessory Dwelling Unit Hotline (781) 745-0000

Will an ADU fit in my backyard?

Now that you’re starting to get excited about building an ADU, you’re probably going to need to know if an ADU will actually fit in your backyard. Great question, let me get into some details.

Ok, let’s talk about sizes. In Massachusetts, ADUs can range from a small studio unit(around 400 sq ft), to a large two-bedroom unit(up to 1200 sq ft). The size of the ADU that you can build depends on how big your property is, zoning laws, and of course your personal preference.

When trying to determine if an ADU will fit in your backyard, here are a few things to consider as you look around and measure your property.

1. Most cities and towns require a certain amount of space between your ADU and the property lines. Be sure to check the specifics.

2. Zoning laws can limit the percentage of your lot that can be covered by structures. This would include the main house, an ADU, and any other buildings.

3. A lot of municipalities will require a dedicated parking space for each ADU.

4. Make sure you think about how you will connect all the utilities to the ADU(such as water, sewer, electric, etc). Depending on where these connections are on your property, it could limit where you can build your ADU.

5. Don’t forget to leave room for a nice outdoor space like a grassy area or a patio.

Sometimes it can be hard to make sure you are within all the guidelines. I would recommend reaching out to a local contractor who specializes in ADUs so they can walk you through assessing your property and decide whether it would be practical to build an ADU in your backyard.

But there is also another option, which would be to turn your garage into an ADU or even attach one to the house. For most people, converting a garage or carport is a very cost-effective way to go, and it conserves your yard space as well. The attached additions are great for the same reason, you don’t have to sacrifice limited backyard space.

Ultimately, there are some great options. Just remember, the size of the ADU you can build will depend on your property’s extra space and the local building codes. But you can determine the best option for you by working with a professional to assess your property and start bringing your vision to life.

Will it fit? Call Cozy Nest Creators To Find Out (781) 745-0000

Pro ADU Tips From First-Time Builders

First, have a very clear vision of what you want. Start with the main goals you have. Will it be a rental unit for extra income? Will it be for elderly parents or other family members? Perhaps a home office. Once you have established your goals, then you can move on to design and construction. This will make it easier to make decisions as the process moves forward.

Familiarize yourself with the town or city zoning regulations. Every city/county can have different laws, so you want to make sure to educate yourself on the ones where you live.

Building an ADU, especially for the first time, can be exciting and overwhelming at the same time.

Only hire licensed and insured contractors/professionals. ADUs can have unique challenges, so it is best to hire professionals who specialize in building them. Hiring the wrong people for the job will end up costing you in the end.

Remember that it is very important to communicate with the team of people you hire for the job. Be sure to check in frequently and make sure everybody is on the same page. That way, if there are issues, they can be dealt with quickly and efficiently.

Decide on a realistic budget, leaving plenty of room for unexpected costs. As I’m sure you can imagine, the costs of ADUs can vary quite a bit. Size, materials, and design are just a few things that factor into the cost of building an ADU. When making your budget, a few things to factor in are the cost of permits, labor, and materials.

Always consider the long-term. Think about your perfect ADU, and consider how it will be used now and in the future. Could it be adapted for other uses down the road? Simplistic designs can often be changed easily to create a more flexible space, and therefore be more valuable in the long run.

We’ve put together a few pro tips to help navigate you through the whole process.

Small things can often make a very big difference in how your ADU functions and looks. Every little thing can add to its appeal. Efficient storage spaces, LED lighting, energy-efficient appliances, modern décor, etc.

Be considerate of your neighbors. Things like construction noise and vehicles can really affect your neighbors. It is best to communicate with them about your plans so they can adjust accordingly and so you can help address any of their concerns.

How Much To Build An Accessory Dwelling Unit?

One of the most common questions homeowners have when considering an ADU is, “How much will it cost?”

As we mentioned earlier, cost is going to depend on a few main factors, which we will talk about. But as a general ballpark range, typical ADUs are going to be between $150,000 and $400,000. Here are the main things that are going to affect cost when building an ADU.


As with any construction project, the bigger it is, the more it will cost to build.


The quality of the materials you choose, such as flooring, paint, insulation, and windows, can vary quite a bit. Adding things like crown molding, custom cabinets, and other upgraded finishing touches can increase the cost of the overall project more than you think. Many people stick with more standard options to help keep within their budget.


The layout of your property can have a dramatic effect on the construction costs. For example, if there is a steep slope in your backyard that would require excavators and things like that, it will up your budget. Also, if you are going to need to upgrade the utilities or even put in a second septic system, that is going to increase costs as well.


Within Massachusetts, big city areas like Boston or Cambridge tend to have higher labor and material costs than other less populated areas.


The last thing on our list is fees and permits. You may need zoning and building permits, which can cost quite a bit. When you add in possible extra utility connection fees, you could be adding several thousand dollars to the overall budget.

Don’t forget that ADUs have huge financial benefits in the long term. The cost of building may seem a bit overwhelming, but it is an investment that can have significant returns in the future, such as increased property value and rental income. For the majority of homeowners, an ADU is a wonderful investment into their property and their future.

Picking The Right ADU Contractor

Choosing the right contractor is of the utmost importance when you are ready to break ground on your ADU. A contractor who has skills and experience will make all the difference in the overall process. You want it to go smoothly and efficiently, so here are some tips on picking the person for the job.



Always make sure a contractor is licensed, bonded, and insured in the state of Massachusetts. The Massachusetts Office of Consumer Affairs and Business Regulation can verify all that information for you. You also want to make sure that your contractor has liability insurance and workers comp as well. Accidents do happen.


Do your research on local contractors who specialize in ADUs specifically. Ask them questions about zoning laws, building codes, and permits to make sure they are knowledgeable and professional. Don’t forget to always ask for references for other projects they have done.


When talking to your contractor, be sure and clearly explain in detail your vision of the finished project and what you are hoping to accomplish by adding an ADU to your property. They should listen and offer helpful suggestions and really strive to achieve the vision you have in mind.

Building an ADU is a significant investment, so take your time when choosing a contractor. Do your research, ask a lot of questions, trust your instincts, and you will find the perfect person for the job.


Communication is key not only for your contractor but for your whole team. A building project like this requires everybody to be on the same page and to be very open with communication. You want a contractor who is responsive and easy to work with, as you will be collaborating with them for the entire project.


Make sure that you thoroughly read any contract given to you by your contractor before signing. Check for important details like work timelines, payments, warranties, or guarantees. Always ask questions if you’re not completely clear on anything. Request changes if need be as well.


Trust your instincts! When interviewing a contractor, if you feel like something is off or isn’t right, don’t ignore it. If something seems like it’s too good to be true it usually is. Get clarification on all points, and only choose someone you feel comfortable and confident with. References are a great way to see if they stand behind their work as well.

Explore Accessory Dwelling Unit Plans

Now that most of the boring stuff is out of the way, let’s talk about the fun part: coming up with and exploring all the plans and designs! There are endless options for every shape and size of ADU. Here are some popular plans and ideas. Keep in mind that any type of ADU can be decorated any way you like, from traditional, to farmhouse, to modern.

Detatched Studio

This is a very popular ADU and would be like a mother-in-law suite, or carriage house. If you do happen to have the backyard space and the budget for a larger project, a two-bedroom can provide an even wider range of benefits, such as more rental income, or extra space for family members. They run quite large, 800-1200 sq ft, and often have not only 2 bedrooms but 2 bathrooms as well, in addition to the kitchen and living area.

Garage Conversion

A lot of people go with this option because it cuts down on the cost and time of construction. Since the bones are already there, typically you would just add insulation, and utilities, and do the inside finish work(painting, carpet, etc). This is a great option if you do not have enough backyard space to add a new structure.

Above-garage Apartment

These are similar to a garage conversion, but without having to give up your garage space OR your backyard space. They include a staircase, bedroom, bathroom, kitchen, and living area.

Attached Apartment

Tend to be a little bigger than a studio space, maybe 600-800 sq ft. They usually have one to two bedrooms, living area, kitchen, and bathroom. People use them a lot for long-term rentals.

Attic or Basement Conversions

Attic and basement conversions are two excellent options for homeowners looking to add an ADU without sacrificing yard space. Both types of conversions transform existing space within the home into a cozy one-bedroom unit with a living area and bathroom. Attic ADUs typically range from 400-600 sq ft, while basement ADUs are slightly larger, ranging from 500-800 sq ft. Access to these units is usually through an interior staircase, although some basement conversions may feature a separate exterior entrance for increased privacy. While neither type of conversion usually includes a full kitchen, they may incorporate a small kitchenette with a microwave, mini-fridge, and sink.

ADU Building Codes For Massachusetts Cities

Before you delve too far into your ADU project, it’s very important to learn about the building codes and laws where you live.

The Healey Driscoll Affordable Homes Act has made it easier to build ADUs in Massachusetts, but every city and town still has its own regulations and requirements that you need to check into. Here are some of the most important things to check for.

To get the specifics on all these codes and guidelines, you will want to contact the local zoning officer or building department. They should be able to easily give you all the specific requirements that pertain to you and also provide information on permits you may or may not need.

It’s always better to work with local professionals who know the area and are familiar with local regulations. Someone with the right experience can help make sure that you are always in compliance with the city ordinances and make sure the permitting and construction process go smoothly.

Height Minimums
ADUs are pretty much limited to one or two stories, depending on the type. Sometimes detached ADUs have different height requirements than garage conversions or attached units.

We talked about this a little bit earlier on, but a “setback” says how far your ADU must be from the property lines. They can vary quite a bit depending on the size and type of ADU you are building, so make sure to double-check.

Your city or town might require you to provide a dedicated parking spot for the ADU. However, in densely populated areas that are near public transportation, sometimes it is not required.

In some places, it is required that the owner live on the property in the main house. The reason for these laws is to prevent investors from buying up multiple properties for the purpose of building ADUs to rent out.

ADUs must be connected to basic utilities (water, sewer, electric). You need to check with your city or town to see if you are able to connect your new ADU to the main utilities on the property, or if you have to put in separate connections.

In some places, there are specific guidelines pertaining to the look and style of your ADU. They might restrict certain colors, features, or materials that don’t complement the primary home.

Size Restrictions
Most places are going to have a maximum size allowed when you build an ADU. The average max is 800-1200 sq ft, but keep in mind that some laws have minimum size requirements as well.

Can I Rent My Accessory Dwelling Unit?

Building an ADU has many attractive benefits, but the one we are going to talk about is rental income! Many people in Massachusetts opt to rent out the ADUs as long-term or short-term rentals using sites like Airbnb or VRBO. Yes, there are tons of profits to be made, but before you get too excited you need to understand the regulations on renting and consider a few things.

First, let’s talk about long-term rentals. In most places in Massachusetts, you are allowed to rent out your ADU long-term. Which can of course provide a great steady stream of income and offset the cost of building it. If you go this route, you’ll need to make sure you follow the local landlord-tenant laws, which cover things like lease agreements, deposits, and evictions.

Now, short-term rentals are a little different. There are different regulations in every city with their own specifics dealing with short-term rentals. Some have almost no rules at all, while others have registration requirements, safety inspection requirements, and occupancy limits. You can find all this information at your local zoning office or building department. Don’t forget to check with your HOA to see if they restrict or prohibit short-term rentals.

If short-term rentals are allowed in your area, here are a couple of things to think about. Renting out an ADU short-term is much more involved and requires more management. There will be bookings to deal with, regular thorough cleanings, and any additional needs of your guests to consider. There can also be more wear and tear on your ADU if there are a lot of different guests coming in and out.

With these types of rentals, there can also be lodging or occupancy taxes. Be sure to add these to your budget and make sure you always abide by tax laws.

Even with all these things to think about, a lot of people still find that renting their ADU to short-term renters still turns out to be quite profitable at the end of the day. Much like a hotel, you can adjust your rates for the seasons or demand, and you control how often it is occupied by guests. On top of all that, a lot of homeowners say it turned out to be a fun and very rewarding experience.

Whether you decide to use your ADU for long-term or short-term rental will all depend on the goals you have and what your city or town allows. Just make sure to do your research and weigh all the pros and cons before deciding on a plan for your rental.restrict or prohibit short-term rentals.

Energy Efficiency & Environmental Impacts

As you are making plans for your ADU, you’ve already put a lot of thought into the financial benefits and the convenience of it, but what about the environmental aspects? Things like energy-efficient appliances or solar panels can make your ADU environmentally friendly, sustainable, and more cost-effective all at the same time. Here are some things that can impact your energy efficiency and carbon footprint.
Insulation Good quality insulation can make a huge difference in controlling temperature and reducing cost and energy use overall. You can use environmentally friendly materials like wool, cellulose, or denim to insulate walls, ceilings, and floors.
Windows and Doors Always choose Energy Star-rated windows and doors because they are great at preventing heat loss in the winter and keeping the heat out in the summer. You want to look for windows that are double or triple panes with low-energy coatings and air-tight seals. When designing your ADU, place windows where they will provide natural light and ventilation, this way you need less indoor lighting and cooling.
Heating and Cooling As with appliances and other materials, you want to get the systems that are the most energy efficient. There are many options from ductless mini-split heat pumps, to floor heating, to high-efficiency air conditioners that can keep your ADU temperature controlled while reducing your energy bills and having less impact on the environment as well. Don’t forget to use natural shade to reduce cooling needs as well.
Appliances and Lighting There are countless Energy Star-certified appliances you can choose from, such as refrigerators, stoves, dishwashers, and washer/dryers. You can also choose to use LED lights. All of these things will cut down on energy/water usage and costs.
Water To bring down your water consumption you can install only low-flow toilets, faucets, and showers. You can also add a greywater system, which recycles water from sinks and showers and uses it for landscape watering or toilets. Another great sustainable source of water, if you have the budget and space for it, is a rainwater collection system.

Materials Use sustainable materials that are recycled, renewable, or locally sourced. You can add things like bamboo flooring, recycled glass countertops, or reclaimed wood to reduce your impact on the environment while giving your ADU style and character. Some materials can actually put off harmful gasses(like VOC’s), which affect indoor air quality.

If you want to take your ADU’s sustainability to the next level, seek out a green building certification like LEED or Passive House. This can help to aid in construction that is highly energy-efficient and eco-friendly. These things can add to your initial budget but can save you a lot of money in the long run while making sure your ADU is a clean and healthy living environment.

By making these things a priority, your ADU will be comfortable, energy-efficient, and impact the environment as little as possible. Also, keep in mind that there are a lot of cities in Massachusetts that offer incentives and rebates for green building features. They would be worth checking into to see if your ADU would qualify.

About Cozy Nest Creators

Now you have a knowledgeable guide to building your first ADU, you understand the benefits and rules associated with making the right plans and hiring the right contractor.
Always take your time in making decisions and doing your research, and never hesitate to ask a professional if you have any questions at all. Plan carefully and your ADU will become a valuable and fun addition to your home and neighborhood.

Under the leadership of CEO Buz Artiano, Cozy Nest Creators specializes in crafting ADUs that are not only cost-effective but also environmentally sustainable and tailor-made to meet the unique needs of each client.

Cozy Nest Creators offer versatile Accessory Dwelling Units (ADUs) designed for various needs, such as accommodating families, rental income, or expanding living space. Their ADUs feature modern, durable construction with energy-efficient designs, and elegant finishes, and are equipped with essential appliances for immediate use. With over 40 years of experience and a skilled team, they ensure a seamless transition with a quick construction timeline. Their compact yet spacious ADUs come with customizable options, offering comfort and low-maintenance living.

Buz Artiano
CEO of Cozy Nest Creators

Transform Your Property Today with Cozy Nest Creators! Contact us to get started with the intial Zoom meeting now.

Discover the perfect blend of modernity, versatility, and efficiency with Cozy Nest Creators, where our Accessory Dwelling Units (ADUs) redefine comfortable living through new construction quality, energy efficiency, and thoughtful design, offering you an elegant and customizable space that truly feels like home.