As housing costs soar and space becomes a premium, more homeowners are turning to Accessory Dwelling Units (ADUs) as a solution.

ADUs offer a versatile, cost-effective way to add living space, whether for family members, rental income, or simply maximizing your propertyโ€™s potential.

But before you dive into building one, there’s a first step: understanding what states allow ADUs.

ADU regulations are patchwork across the United States. They are all over the place.

adus welcome

Eventually, (fingers crossed) all states will become ADU-friendly.

In this article, we’ll break down which states fully embrace ADUs housing, where you might face some hurdles, and which areas make it much harder.

Side Note: The list in this article is based on current legislation and the research I have compiled. There may be some that do not entirely agree. ๐Ÿ‘๐Ÿป

Letโ€™s take a closer look at where your state stands.

Info

As Legislation continues to evolve and adapt to ADUs, this article may become outdated.
Help us keep it updated by emailing any changes you see that need to be updated. I appreciate you!

Key Takeaways
  • The ability to build an ADU varies significantly by state and local regulations.
  • States like California and Oregon are leading in ADU-friendly legislation, making it easier to add these units.
  • Other states may allow ADUs with specific conditions, such as owner-occupancy requirements or design restrictions.
  • Some states remain restrictive, making ADU development challenging or nearly impossible.
  • ADU laws are evolving, driven by the growing need for affordable and flexible housing solutions.
  • Researching and understanding state and local regulations is essential before planning an ADU.
  • Your state could dictate what type of ADU you can build.

Disclosure: This post may contain affiliate links, meaning I can earn commissions. If you decide to purchase through my links, it is at no cost to you.

The Legal Landscape of ADUs

grayscale photo of concrete building

ADU Regulations: A Patchwork of Laws

ADU regulations are far from uniform across the United States.

Some states have embraced ADUs as a solution to housing shortages and affordability crises, while others have placed significant restrictions on their development.

This variability means that even if your state allows ADUs, you may still face challenges at the county/parish or city level.

State vs. Local Control

While state laws often set the framework for ADU regulations, local governments typically have the final say in how ADUs are implemented.

Some states have passed laws to override restrictive local ordinances, ensuring that ADUs are allowed statewide.

Other states leave the decision entirely to local jurisdictions.

which states allow adus

States That Fully Embrace ADUs

The_Most_ADU_Friendly_States

This list of states that allow ADUS and are the most ADU-friendly includes:

California

California is a pioneer in ADU-friendly legislation. The state has passed several laws to:

  • Reduce barriers to ADU construction
  • Remove parking requirements
  • Allow ADUs in single-family zones
  • Streamline the permitting process

These changes have made California one of the most accessible states for ADU development.

Note

In some parts of California, you can sell an ADU separately from the main property as an ADU Condo.

Connecticut

Connecticut encourages ADUs through state legislation that simplifies the approval process and supports local efforts to increase housing availability.

Hawaii

Hawaii supports ADU development as a way to address its significant housing shortages, particularly on the more densely populated islands.

Maine

Maine has adopted state laws that promote ADU development, particularly in urban areas where housing shortages are most acute.

Massachusetts

Massachusetts has taken steps to support ADU development, with some cities and towns offering incentives or reduced restrictions to encourage homeowners to build ADUs on their properties.

New Hampshire

New Hampshire has passed laws that require municipalities to allow ADUs on any property where a single-family home is allowed, making it easier for homeowners to add an ADU.

Oregon

Oregon has followed Californiaโ€™s lead by enacting statewide laws that support ADUs.

The Oregon stateโ€™s legislation allows ADUs in most single-family zones and includes provisions to encourage their development, such as reduced fees and relaxed design standards.

Rhode Island

Rhode Island permits ADUs with relatively relaxed restrictions, especially in areas facing housing shortages.

Vermont

Vermont has big plans for ADUs even though it is such a small state.

The state has adopted legislation that encourages the development of ADUs by simplifying the approval process and offering financial incentives for homeowners who build them.

Washington

Washington has embraced ADUs as a solution to the stateโ€™s housing challenges.

Cities like Seattle have been leaders in promoting ADU development through relaxed zoning laws and streamlined permitting processes.

States with Conditional ADU Allowance

ADU_with_Conditional_Allowance

Arizona

Arizona permits ADUs in certain zones, particularly in urban areas.

However, the conditions for building an ADU can vary significantly between municipalities.

Colorado

Colorado allows ADUs, but the stateโ€™s regulations come with several conditions.

For example, many cities require that the property owner lives on-site or that the ADU meets specific design criteria.

These conditions can make it challenging to build an ADU in some parts of the state.

Florida

Floridaโ€™s approach to ADUs is generally positive, but the state has left much of the decision-making to local governments.

In some areas, ADUs are welcomed, while in others, restrictions on size, occupancy, and parking can limit their feasibility.

ADU Zoning Resources for Florida
ADU Zoning for St. Petersburg

Georgia

In Georgia, cities like Atlanta have embraced ADUs, but statewide, the regulations are inconsistent.

Local ordinances play a significant role in determining whether an ADU is feasible.

Illinois

Illinois allows ADUs in some cities, particularly in urban areas like Chicago, but local zoning laws can present challenges depending on the specific location.

Indiana

Indiana allows ADUs in some urban areas, but local zoning laws and restrictions can pose challenges for homeowners looking to develop an ADU.

Iowa

Iowa allows ADUs in some cities, but local zoning laws and conditions can significantly impact the feasibility of ADU development.

Kansas

Kansas permits ADUs in certain cities, particularly in urban areas, but local regulations can vary significantly, making it important to consult with local planning authorities.

Maryland

Maryland permits ADUs in some jurisdictions, such as Baltimore, where local governments have recognized the potential for ADUs to increase affordable housing options.

Michigan

Michigan allows ADUs in certain areas, particularly in urban environments, but local zoning restrictions can limit where and how ADUs can be developed.

Minnesota

Minnesota allows ADUs in some cities, but with significant local restrictions that can make the development process complex and time-consuming.

Missouri

Missouri allows ADUs in some areas, such as St. Louis, but local zoning laws often impose strict conditions on their development.

Nevada

Nevada permits ADUs, particularly in urban areas, but there are often conditions related to lot size, design standards, and parking requirements that vary by municipality.

New Jersey

New Jersey permits ADUs, but the stateโ€™s approach is highly dependent on local ordinances, which can vary significantly from one municipality to another.

North Carolina

North Carolina allows ADUs, but the specific regulations depend heavily on local zoning laws.

Some cities are more ADU-friendly than others, making it important to research local requirements.

Ohio

Ohio permits ADUs in some cities, particularly in urban areas, but homeowners may face significant local restrictions that complicate the development process.

Pennsylvania

Pennsylvania allows ADUs in some urban areas, particularly in Philadelphia, but local regulations can vary widely, affecting the ease of development.

Texas

In Texas, ADU regulations vary widely depending on the city.

While Austin has been a leader in promoting ADUs, other cities in the state have placed significant restrictions on their development.

This conditional allowance highlights the importance of checking local ordinances before planning an ADU.

Utah

Utah allows ADUs in some areas, but there are often local regulations and conditions, such as owner-occupancy requirements and design standards, that must be met.

Wisconsin

Wisconsin permits ADUs in cities like Milwaukee, where local governments have recognized the need for more affordable housing options.

States with Restrictive ADU Policies

States_with_Restrictive_ADU_Policies

Alabama

Alabama is another state where ADUs face significant hurdles.

Local zoning laws and community opposition often prevent homeowners from adding ADUs to their properties, making it one of the more challenging states for ADU development.

Alaska

Alaskaโ€™s zoning laws vary widely by municipality, but in general, the state has restrictive policies that can make ADU development challenging.

Arkansas

Arkansas has strict zoning regulations that make it challenging for homeowners to build ADUs.

Local governments often impose significant restrictions on ADU development.

Delaware

Delaware has restrictive zoning laws that limit the development of ADUs, particularly in suburban and rural areas.

Idaho

Idaho permits ADUs in certain municipalities, but statewide adoption of ADU-friendly policies is limited, making it important to check local regulations.

Kentucky

Kentucky has restrictive zoning laws that limit the ability to build ADUs, particularly in suburban and rural areas.

Louisiana

Louisianaโ€™s local governments have generally taken a restrictive approach to ADUs, with zoning laws that often prohibit or severely limit their development.

Mississippi

Mississippi has some of the most restrictive zoning laws in the country, making it difficult to build ADUs in most areas of the state.

Montana

Montana allows ADUs in some areas, but restrictive zoning laws and local opposition can make it challenging for homeowners to develop these units.

Nebraska

Nebraska allows ADUs in some urban areas, but restrictive zoning laws and local opposition often limit their feasibility.

New Mexico

New Mexico allows ADUs in some cities, but the stateโ€™s overall approach is restrictive, with many areas imposing significant conditions on their development.

New York

Despite the stateโ€™s housing needs, New York has some of the most restrictive ADU regulations in the country.

Zoning laws in many parts of the state, particularly in suburban areas, make it difficult to build ADUs.

Homeowners often face significant challenges in navigating these restrictive policies.

North Dakota

Similar to South Dakota, North Dakota has restrictive ADU policies, with limited opportunities for homeowners to develop these units.

Oklahoma

Oklahoma has restrictive zoning laws that limit the development of ADUs, particularly in suburban and rural areas.

South Carolina

South Carolina has restrictive zoning laws that limit the development of ADUs, particularly in suburban and rural areas.

Homeowners may find it challenging to navigate these regulations.

South Dakota

South Dakota has generally restrictive policies regarding ADUs, with few areas allowing their development without significant conditions.

Tennessee

In Tennessee, ADUs are rarely permitted, with many local governments enacting zoning laws that effectively prohibit their development.

This has led to limited opportunities for homeowners looking to build ADUs in the state.

Virginia

Virginiaโ€™s ADU policies vary significantly by locality, but in general, the state has restrictive zoning laws that can make it difficult for homeowners to build ADUs.

West Virginia

West Virginiaโ€™s zoning laws are generally restrictive regarding ADUs, with limited opportunities for development in most areas.

Wyoming

Wyoming has restrictive ADU policies, with few municipalities allowing their development without significant conditions.

Recent Changes and Trends in ADU Legislation

A Shift Toward More Permissive ADU Laws

In recent years, there has been a noticeable shift toward more permissive ADU laws across the country.

States like California and Oregon have led the way, but others are beginning to follow suit.

permits submitted
ADU Permits in California

Many states are in the process of modifying their regulations. It is a slow process sometimes.

This trend is driven by the increasing need for affordable housing, the desire for more flexible living arrangements, and the growing recognition of ADUs as a practical solution to these challenges.

As more states confront housing shortages, we see legislative changes aimed at making it easier to build ADUs.

These changes often include:

  • relaxing zoning laws
  • streamlining the permitting process
  • eliminating or reducing parking requirements

Some states are even incentivizing ADU construction through grants, tax breaks, or reduced fees.

This evolving landscape means that homeowners may have new opportunities to add ADUs, even in previously restrictive states.

Key States to Watch for ADU Reform

While California, Washington, and Oregon remain leaders in ADU legislation.

These states are actively working to update their housing policies, recognizing the potential of ADUs to provide much-needed housing options.

The_Top_3_Most_Friendly_ADU_States

The Role of Local Governments on ADUs

Even as state laws become more favorable, local governments play a huge role in implementing these changes.

Homeowners should stay informed about both state and local regulations, as local ordinances can still impose significant restrictions, even in states that are generally supportive of ADUs.

Looking Ahead to adu advancement

The trend toward more permissive ADU laws is likely to continue as housing pressures increase and the benefits of ADUs become more widely recognized.

Homeowners considering an ADU should keep an eye on legislative developments, as new opportunities may emerge that make it easier to add an ADU to a property.

Final Thoughts on What States Allow ADUs

Navigating the maze of ADU regulations can feel overwhelming, but the rewards of adding an ADU to your property can be well worth the effort.

Whether youโ€™re looking to create additional income, provide a home for a family member, or simply make better use of your space, knowing where your state stands on ADUs is the first critical step.

As more states recognize the potential of ADUs to address housing shortages and offer flexible living solutions, we may see more permissive laws in the future.

But for now, do your homework, consult with local planning departments, and understand the specific regulations in your area before moving forward.

Frequently Asked Questions

ARE ADUS ALLOWED IN LOUISIANA?

ADUs are allowed in some parishes in Louisiana. Read more on ADU Rules in Louisiana.

How far can an ADU be from the main house?

Most ADUs will need to be at least 10 feet away from the main house.

What is a good size ADU?

A good size ADU with 1 bedroom is between 500-700 square feet.

What is the smallest ADU allowed?

150 square feet is the smallest ADU allowed.

Author
  • Erin Hybart Headshot Home

    Meet Erin, a real estate enthusiast with a wealth of knowledge and an insatiable curiosity for all things Real Estate and living with intention. She passionately advocates for alternative, affordable, and eco-friendly housing solutions. She believes in pushing the industry's innovation boundaries and thinking outside the box. As a licensed real estate agent in Louisiana, Erin dedicates herself to assisting clients in buying and selling properties and mentoring fellow agents to succeed in their own Real Estate businesses. In addition to her professional pursuits, Erin channels her expertise into captivating house-flipping adventures.

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