ADU Regulations in Connecticut: A Comprehensive Guide

Does Bridgeport, CT, Allow ADUs?

Yes, Bridgeport, CT allows ADUs!

You can build attached or internal ADUs in Zones AAA, AA, R-3, R-2, A, B, and C. Detached ADUs are allowed on lots with at least two acres. Your ADU must be no larger than 40% of the main home’s floor area or 1,500 sq. ft., whichever is smaller, and must include one off-street parking space.

The owner must live in either the main home or the ADU. A permit, architectural plans, and full code compliance are required. Some areas may have extra rules, so check with the Bridgeport Zoning Department before starting!

Does Bristol, CT, Allow ADUs?

Yes, Bristol, CT allows the habitation of ADUs!

The city follows the International Residential Code (IRC) through the Connecticut State Building Code. As long as you follow the regulations, you’re free to occupy an ADU in Bristol, CT.

Your ADU must be located within or attached to a single-family home on an existing lot of record, and either the main home or the ADU must be owner-occupied. The ADU must be between 750 square feet and no more than one-third of the primary home’s living area, with a maximum of two bedrooms. It must meet all zoning requirements for single-family dwellings, including setbacks, height limits, and lot coverage, and provide one off-street parking space per bedroom. An interior door must also connect the main home and the ADU.

Additionally, you’ll need building permits and must pass all required inspections. Since local requirements can vary, we recommend checking with the Bristol Department of Land Use to make sure you have the latest information for your property.

Does Danbury, CT, Allow ADUs?

ADUs are permitted in designated residential areas in Danbury, as long as certain conditions are met. The ADU must be either attached to the main residence or located on the same lot. There are also size limitations and parking requirements that you’ll need to follow.

Because local regulations can change, it’s very important to check with the City of Danbury Planning and Zoning for the most up-to-date information and to make sure your project fully complies with all current rules before you get started!

Does East Hartford, CT, Allow ADUs?

ADUs are allowed in East Hartford, CT. By obeying the International Residential Code (IRC), which applies to Connecticut in its entirety, you’ll be able to live in an ADU in East Hartford!
In order to conform to the IRC, your ADU will need to meet the size requirement of 400 square feet or smaller and a ceiling height of 6’8.” Before construction takes place, you need to have a building permit. You will also need to pass inspections once the project is complete.

Some areas in East Hartford may or may not have harsher regulations. To learn more about a specific area in your town, check with the East Hartford Zoning Department.

Does Fairfield, CT, Allow ADUs?

Yes! Fairfield permits ADUs in specific residential zones, including AAA, AA, R-3, R-2, A, B, and C for attached units. Detached (free-standing) ADUs are allowed in Zones AAA, AA, and R-3, provided the lot meets setback and other design requirements.

The ADU must be no larger than 40% of the primary home’s floor area or 1,500 square feet, whichever is smaller. It must have its own kitchen, bathroom, and entrance, and at least one off-street parking space must be provided. The homeowner must live in either the primary residence or the ADU.

If you are building an ADU in Fairfield, you must first apply for a written permit and provide plans showing the proposed changes. The ADU must meet all applicable housing, building, fire, and health code requirements.

Local regulations can change, so we highly recommend contacting the Fairfield Town Plan & Zoning Department before starting your project to ensure you have the most accurate and updated information!

Does Greenwich, CT, Allow ADUs?

Yes! The Town of Greenwich, CT allows ADUs!

The rules declare that external ADUs must be a maximum of 800 square feet in size, but may be allowed up to 1,000 square feet with Planning & Zoning Commission approval. Only one ADU is allowed per single-family property, and it must remain clearly secondary to the main home, with no second front door visible from the street. Either the main home or the ADU must be owner-occupied, and at least one off-street parking space must be provided for the ADU.

Detached ADUs must meet setback requirements, and garage conversions are permitted if the lost parking is replaced elsewhere on the property. New driveways for ADUs are not allowed, and all ADUs must comply with state and local building, health, and zoning codes.

Before building, it’s important to consult with the Greenwich Department of Land Use to ensure your project meets all requirements.

Does Hamden, CT, Allow ADUs?

Yes, Hamden, CT allows ADUs.

The town follows the International Residential Code (IRC). As long as you follow the regulations, you can have an ADU in Hamden, CT.

Your ADU must measure at least 300 square feet with a maximum floor area of not less than 30% of the principal dwelling unit or 1,000 square feet, whichever is less, and a maximum of 2 bedrooms. The homeowner must live in either the primary residence or the ADU. You’ll also need to acquire building permits from the town and pass all necessary inspections.We always recommend that you check with the Hamden Planning and Zoning Department to learn about the zoning laws in your area.

Does Hartford, CT, Allow ADUs?

Hartford, CT, does allow ADUs!

You can build one internal, attached, or detached ADU per lot in most areas where single-family homes are permitted. The ADU must be no larger than 30% of the main home’s floor area or 1,000 square feet, whichever is less. Either the main house or the ADU must be owner-occupied.

You’ll also need to provide off-street parking, ensure the design fits the look of the main house, and limit occupancy to two people. Utility connections can be shared or separate, and short-term rentals are regulated.

Requirements can vary depending on your location, so we highly recommend you contact the Hartford Planning and Zoning Division for the most accurate and up-to-date information.

Does Manchester, CT, Allow ADUs?

Yes. Manchester allows ADUs that are attached, inside, or detached as long as they meet the 350–1,000 sq ft size range and stay under 30% of the main home’s floor area.

Your ADU must be located on the same lot as the primary residence, and either the main home or the ADU must be owner-occupied. 

The ADU must meet all zoning requirements for single-family dwellings, including setbacks, height limits, and lot coverage. You’ll need to provide at least one off-street parking space for the ADU, but curb cuts on the new driveway are not allowed. The ADU’s exterior access should be located at the side or rear of the dwelling to maintain the residential look from the street.

Additionally, some areas may have more strict rules, so we always recommend checking with the Manchester Planning and Zoning Commission for the most accurate information about your property.

Does Meriden, CT, Allow ADUs?

Yes, Meriden, CT allows the habitation of ADUs!

The city follows the International Residential Code (IRC) through the Connecticut State Building Code. As long as you follow the regulations, you can occupy an ADU in Meriden, CT.

Your ADU must be located on a lot with only one principal building and meet all lot size and bulk requirements. The unit must maintain the home’s original residential character, and exterior changes require approval from the Design Review Board.

Front yard parking is not allowed, and major structural changes are limited. You’ll also need building permits and must pass all required inspections. Additionally, some areas may have stricter rules, so we always recommend checking with the Meriden Planning and Zoning Department for the most accurate information about your property.

Does Middletown, CT, Allow ADUs?

Yes, Middletown, CT allows the habitation of ADUs!

The city follows the International Residential Code (IRC) through the Connecticut State Building Code. As long as you follow the regulations, you’re free to occupy an ADU in Middletown, CT.

Your ADU must be attached to a single-family home and connected through an interior doorway. It must not exceed 800 square feet and must share the same street address, utilities, and driveway as the main residence.

The homeowner must live in either the primary home or the ADU. You’ll also need to obtain building permits and pass all required inspections. Some areas may have stricter rules, so we always recommend checking with the Middleton Department of Land Use for the most accurate information about your property.

Does Milford, CT, Allow ADUs?

Yes, ADUs are permitted in Milford, CT.

The city is accommodating toward ADUs due to being compliant with the International Residential Code (IRC) which has rules regarding ADUs.

To meet IRC requirements, your ADU must be, at most, 400 square feet and have at least 6 feet and 8 inches of space between the floor and ceiling. You must obtain a building permit from the city and pass the inspections once your house is completed.Contact the Milford Planning and Zoning Office to find out if your area has any ADU-related restrictions, as some areas may have stricter laws than others.

Does New Britain, CT, Allow ADUs?

New Britain, CT, does allow ADUs!

However, they are subject to specific regulations. ADUs are only permitted on single-family lots and must be attached to the primary residence, detached ADUs are not allowed.

To build an ADU, the lot must be larger than 8,000 square feet. The ADU itself cannot exceed 800 square feet or 40% of the main home’s floor area, whichever is smaller, and it can have no more than one bedroom.

An ADU requires one off-street parking space, and the owner must reside on the property. It must match the main house in style and materials. Since regulations can change, we recommend you visit the City of New Britain Zoning and Planning Department for the most up-to-date information before moving forward with your project.

Does New Haven, CT, Allow ADUs?

Yes, you can build an ADU in New Haven, CT!

To qualify, your property must be located in an approved zoning district; specifically RM-1, RM-2, RS-1, or RS-2, and the lot must be at least 4,000 square feet. You must also be the homeowner and live on the property.

New Haven has specific zoning rules for ADUs, so it’s a good idea to check with the City of New Haven Zoning and Regulations Department to make sure your project meets all the requirements before getting started!

Does Norwalk, CT, Allow ADUs?

Norwalk, CT, does indeed allow ADUs.

Under local zoning regulations, ADUs are permitted on properties with single-family homes, whether attached to or detached from the main house. Detached ADUs can be up to 700 square feet, while attached ADUs can be up to 1,000 square feet. Property owners must live on the premises, provide at least three off-street parking spaces, and ensure the ADU matches the architectural style of the main home.

Detached units also require specific setbacks and landscaping buffers. Building permits and either zoning approval or site plan review are necessary, depending on whether the ADU is attached or detached. Since some neighborhoods may have additional requirements, it’s best to contact the Norwalk Zoning Regulations Department to make sure you have the latest information before starting your project.

Does Stamford, CT, Allow ADUs?

Yes, Stamford, CT allows ADUs, but with certain conditions!

In 2022, Stamford adopted its own ADU rules, opting out of the broader state regulations. You can build an ADU on a single-family lot that’s at least 10,000 square feet. The unit can be up to 800 square feet in size and house up to three people.

The property owner must live in either the main home or the ADU, and you’ll need to provide at least one off-street parking space. Short-term rentals like Airbnb are not allowed. Since Stamford’s rules are more specific than the state’s, we recommend contacting the Stamford Zoning Board to make sure you have the latest information before you start!

Does Stratford, CT, Allow ADUs?

Yes, Stratford, CT allows the habitation of ADUs!

The city follows the International Residential Code (IRC) through the Connecticut State Building Code. Stratford requires the occupants to be family members. The accessory unit must connect to the other unit via an interior doorway. It must be at least 400 square feet and cannot exceed 800 square feet or 25% of the total livable area of the overall residence, whichever is smaller. Since regulations may change with time, we suggest contacting the Stratford Office of Planning & Zoning for the latest information before starting your project.

Does Waterbury, CT, Allow ADUs?

Yes, Waterbury, CT, allows accessory dwelling units ADUs.

Waterbury adheres to the state’s default ADU regulations.​ Under these regulations, homeowners in Waterbury can add one ADU per lot, whether attached, detached, or internal to the primary residence. The unit must be no larger than 1,000 square feet or 30% of the main dwelling’s floor area, whichever is less. Importantly, towns cannot impose requirements such as age restrictions for occupants, mandates that tenants be related to the homeowner, or parking requirements exceeding one space per unit. ​

If you’re considering building an ADU in Waterbury, you should consult the City Planning, Zoning & Inland Wetlands Department for the most current permitting procedures and any local guidelines.

Does West Hartford, CT, Allow ADUs?

Yes, West Hartford, CT, does allow ADUs!

In single-family residential areas, one ADU is allowed per lot as long as it stays secondary to the main home.The ADU must have its own kitchen, bathroom, and sleeping facilities. It can be either attached or located in a detached accessory building. The maximum size of the ADU is limited to 1,000 square feet or 30% of the principal dwelling’s gross floor area, whichever is smaller.

Owner occupancy is required in either the main home or the ADU, and at least one off-street parking space must be provided for the ADU without reducing the parking available for the main house. Detached ADUs must meet specific side and rear setback requirements, and ADUs must maintain the one-family residential character through careful design, materials, and orientation. Regular affidavits confirming owner occupancy are also required if the unit is rented. As always, it’s best to check with the West Hartford Zoning and Planning Department for the latest regulations before starting your project.

Does West Haven, CT, Allow ADUs?

Yes, West Haven, CT allows the habitation of ADUs.

While the city has opted out of Connecticut’s Public Act 21-29, which standardizes ADU regulations statewide, West Haven permits ADUs under its own zoning regulations. These regulations may differ from the state law in aspects such as unit size, location, and parking requirements. Therefore, it’s essential to consult the city’s zoning code or contact the Planning and Zoning Department for specific guidelines applicable to your property.​

Your ADU must have a size limit of 550 square feet. It’s important that you have a proper building permit and meet the requirements to pass all the inspections.Keep in mind that zoning rules can vary within the city, so it’s best to contact the West Haven Planning and Zoning Commission before moving forward with your project.