Across Indiana, homeowners are taking a closer look at Accessory Dwelling Units (ADUs) as a way to expand their living options without relocating. If it’s adding space for extended family, creating a long-term rental, or carving out a separate living area on the same property, ADUs are becoming part of the conversation in both urban neighborhoods and outlying communities.
Indiana approaches ADUs through local zoning rather than a single statewide standard, which means the rules can shift from one city or county to the next. Some municipalities have embraced ADUs with clearer guidelines, while others still regulate them through accessory-structure or special-use provisions. Understanding how your local planning department defines and permits an ADU is an important first step before moving forward.
This guide is designed to help Indiana homeowners understand how ADUs are regulated across the state and what to expect during the planning and approval process. Zook Cabins is here to provide clarity and support as you explore whether an ADU is the right addition to your property.
Are ADUs Allowed in Indiana?
Yes, ADUs are allowed in Indiana, and the state has increasingly modernized its approach to secondary dwellings to help property owners maximize their land. While Indiana does not have a single statewide mandate that applies to every city, many of its major jurisdictions and rural counties have established clear paths for adding a small secondary home on a single-family lot. This local-led approach means that while most areas are welcoming to ADUs, homeowners should be prepared to review the specific zoning details and procedures for their particular town or county.
Indiana’s framework for ADUs is built on a foundation of local control, where each city or county determines its own rules for size, setbacks, and height. In many municipalities, ADUs are now treated as a permitted use in specific residential zones, while others may require a special exception through the Board of Zoning Appeals. Most local codes also require that the ADU remain subordinate to the primary home and that the property remain owner-occupied in at least one of the units. This local flexibility allows each community to ensure that new housing fits the character of existing neighborhoods.
If you are considering adding an ADU in Indiana, this guide walks through the key details for homeowners and highlights what you can expect in different parts of the state.
What Is Considered An ADU in Indiana?
An Accessory Dwelling Unit is defined as a secondary, self-contained residence that shares a single-family lot with a primary home. Often referred to as a carriage house or a guest suite, these structures are designed to function as independent living quarters, featuring their own dedicated spaces for sleeping, cooking, and sanitation. While they are built to the same high standards as a standard house, they are legally recognized as subordinate units that add versatility and value to a property.
A legal ADU in Indiana typically includes:
- A separate entrance (interior or exterior)
- Its own kitchen or kitchenette
- A private bathroom
- A dedicated living/sleeping area
- Full compliance with residential building code, fire safety, and utility standards
Homeowners have several options for adding an ADU, including converting internal spaces like basements or attics, adding an attached addition, or building a standalone cottage in the backyard. Most communities across the state recognize these diverse configurations as long as the project follows local development standards, such as height limits, setback requirements, and density rules. While specific details like maximum square footage often vary by city or county, the general goal remains consistent: providing a fully functional, subordinate living space that blends with the existing neighborhood. This local flexibility allows property owners to choose the setup that best fits their lot while ensuring the new unit meets all state and local building safety codes.
Can Park Model ADUs Be Used As ADUs?
In Indiana, the qualification of park model homes as ADUs depends on how the structure is built and installed according to the Indiana Residential Code. While the state officially recognized tiny homes in 2020 by adopting specific residential standards, these rules primarily apply to units designed for permanent living rather than recreational use. Because of this distinction, a traditional park model built to RV standards and kept on wheels is typically classified as a recreational vehicle rather than a legal dwelling.
To qualify as a legal ADU in most Indiana jurisdictions, a unit must be placed on a permanent foundation and meet the same life-safety, structural, and utility requirements as a standard home. This means that while a park model may look like a small cottage, it will only be accepted as an ADU if it is built to the state’s residential building codes and is permanently affixed to the ground. Units that are built to these higher standards and include the necessary kitchen and bathroom facilities have a much clearer path to being approved as detached secondary residences.
Local zoning ordinances often play the final role in determining whether a park model-inspired structure is allowed on your lot. Many Indiana cities and counties have specific square footage minimums or maximums and may require the unit to share utility connections with the primary house. It is essential to consult with your local planning department to verify that your chosen model meets the specific definition of a permanent residential structure and complies with the zoning district’s height and setback rules.
Can Log Cabins Be Used As An ADU?
Log cabins can serve as ADUs if they are designed and built to the same residential and zoning standards required for any other permanent home on a property. Because Indiana relies on localized planning commissions to manage housing density, a cabin must be constructed as a legitimate dwelling rather than a temporary or recreational structure. This ensures that the unit complies with the state’s building codes while fitting into the residential character of the community.
To be recognized as a legal ADU, a log cabin must function as a fully independent living space. This includes having a dedicated bathroom, a kitchen setup, a sleeping area, and permanent utility connections that are inspected and approved by local authorities. As long as the cabin is placed on a permanent foundation and follows the local residential permitting process, it is generally treated as an acceptable detached secondary residence in jurisdictions that allow for accessory units.
Log cabins built solely to RV or seasonal campground standards are typically not permitted as permanent ADUs in Indiana. Since most local ordinances exclude recreational vehicles from being used as long-term dwellings, a cabin on wheels or one without a residential-grade foundation will likely be classified as an RV. If you are planning a log-style ADU, it is important to confirm with your local building department that the specific model you have in mind meets the structural requirements for a permanent residential building.
Can Modern Cabins Be Used As An ADU?
Modern cabins are a popular choice for Indiana homeowners looking to add an ADU, provided they are constructed to meet the state’s residential building standards for permanent housing. Indiana law does not restrict the architectural style of a secondary dwelling, meaning a sleek contemporary cabin, minimalist studio, or modern modular home can all qualify as long as they function as independent residences. To be legally recognized, these units must feature their own dedicated kitchen, bathroom, and sleeping areas, and they must be installed on a code-compliant, permanent foundation with fixed utility connections.
Since Indiana operates under a “home rule” system, the specific permitting and inspection procedures are managed by your local city or county planning department. This means that while the state allows the use of modern cabin designs, local rules regarding setbacks, building height, and maximum square footage will vary depending on your specific zoning district. Some Indiana municipalities also have design compatibility requirements, which may influence the exterior materials or roof pitch of your modern cabin to ensure it fits the look of the neighborhood.
As long as your modern cabin is built to the Indiana Residential Code and you adhere to your local community’s permitting process, it can typically be approved as a detached accessory dwelling. Many cities across the state are increasingly welcoming these high-quality, modern structures as a way to provide flexible living space while maintaining the integrity of the property.
What is the Difference Between a Prefab ADU & a Modular ADU?
The term “prefab” acts as a broad umbrella for any secondary residence constructed in a factory setting before being transported to your property. However, it is important to distinguish between general prefab structures and true modular ADUs, as the two are treated very differently under Indiana building codes. While prefab can describe everything from panelized kits and shed-style buildings to tiny homes on wheels, many of these options fail to meet the “industrialized residential structure” standards required for permanent year-round living.
A modular ADU is a specific type of high-quality prefab construction. Unlike some prefab products that are built to temporary or recreational standards, modular units are constructed in sections, certified during the manufacturing process, and then permanently affixed to a foundation on your site. Because they are built to the same rigorous criteria as a traditional “stick-built” home, they are the most reliable path to securing a certificate of occupancy in Indiana. Check out our guide to prefab vs. modular homes to learn more.
What is the Minimum Size for an Accessory Dwelling Unit?
There is no single statewide minimum square footage that applies to every accessory dwelling unit. Instead, the size of a secondary home is governed by a combination of the Indiana Residential Code and local zoning ordinances. While the state building code focuses on safety and habitability, requiring every unit to feature a dedicated space for sleeping, cooking, and sanitation, individual cities often set their own specific floor area boundaries to ensure the unit remains subordinate to the primary residence.
In many Indiana jurisdictions, such as Indianapolis or South Bend, you will find that a secondary dwelling typically needs to fall between a minimum of 220 square feet and a maximum of 800 to 1,000 square feet. Some cities also use a percentage-based rule, where the unit cannot exceed 50% or 75% of the primary home’s total living area. These numbers ensure the unit is large enough to provide a high quality of life while maintaining the traditional look and feel of the neighborhood.
Can My ADU be Bigger Than My House?
The size of an accessory dwelling unit in Indiana is specifically managed to ensure it remains secondary to the primary home. While the state does not have one universal size mandate like Arkansas, many local jurisdictions follow a similar logic to keep these units proportional to the main residence. In cities like Indianapolis or South Bend, the common standard requires an ADU to be smaller than the principal house, with maximum size limits often capped between 800 and 1,000 square feet.
Many Indiana communities also use a percentage-based limit, where the secondary unit cannot exceed 50% or 75% of the primary home’s total floor area. These restrictions are designed to maintain the residential character of the neighborhood while still providing enough room for a comfortable, self-contained living space. Because these rules are set at the local level rather than by a single state law, the exact cap can vary depending on whether you are building in a dense urban area or a more rural county.
How Close To My House Can I Build An ADU?
The minimum separation between an accessory dwelling unit and the main home is primarily dictated by the state’s residential building codes and the local zoning rules of your specific city or county. Because Indiana uses a home rule system, there is no single statewide distance requirement. Instead, the gap between buildings is usually managed through fire safety standards and local yard setbacks.
Under the Indiana Residential Code, a common standard for fire separation is a minimum of 6 to 10 feet between detached structures on the same lot. If an ADU is positioned closer than this, the building department may require specific fire-resistant materials, such as one-hour fire-rated walls or limited window openings, to prevent the spread of flames between the two buildings.
Local zoning ordinances also play a major role in where you can place a unit. Many Indiana cities, like Bloomington or South Bend, require detached accessory dwellings to be situated behind the front line of the primary house and maintain specific side and rear yard setbacks.
Do You Need A Permit For An ADU in Indiana?
Securing a formal permit is a mandatory requirement before you can begin work on an accessory dwelling unit. Since Indiana operates under a home rule system, the responsibility for managing and issuing these approvals lies with your specific city or county building department. Every ADU is categorized as a residential structure, which means it must undergo a thorough evaluation process to ensure it complies with both local zoning laws and the Indiana Residential Code.
The permitting journey usually starts with an improvement location permit to verify the placement of the unit on your land. From there, you will need a structural permit along with separate trade approvals for electrical, plumbing, and mechanical systems. For homeowners in cities like Indianapolis or Bloomington, this process also involves submitting detailed site plans, drainage evaluations, and floor layouts to ensure the new unit doesn’t negatively impact the surrounding infrastructure.
If you choose a modular or factory-built ADU, the unit itself is often certified at the manufacturing plant through the state’s industrialized building systems program. However, you are still required to obtain local permits for the foundation, site preparation, and the final hookup to utilities. Local inspectors will visit your property to verify that the installation meets all safety standards before the unit can be legally occupied.
Are There Any Incentives or Grants for ADUs in Indiana?
Homeowners in Indiana will find that there are currently no state-sponsored grant programs available to fund the building of an accessory dwelling unit. While some parts of the country have introduced specific financial incentives for ADUs, Indiana’s state housing resources are primarily allocated toward neighborhood-wide infrastructure, first-time homebuyer assistance, or emergency repairs for low-income seniors. This means the total cost of adding a secondary suite or backyard cottage remains the responsibility of the individual property owner.
Local governments across the state also lack dedicated ADU funding or specialized grants for residential expansion. In cities like Indianapolis or Bloomington, municipal housing grants are almost exclusively reserved for addressing critical safety hazards, such as lead removal or structural stabilization, rather than new construction. Consequently, most Indiana residents look to traditional private financing routes, such as using home equity through a HELOC (Home Equity Line of Credit) or securing a specialized construction-to-permanent loan, to cover the investment.
The only significant local incentive currently available in Indiana is found in the City of Bloomington, which invested in several pre-approved ADU designs. While this is not a direct cash grant, it can save homeowners thousands of dollars in architectural fees and help speed up the local permitting process. Aside from these types of administrative perks, those looking to build an ADU in Indiana should plan to fund the project through personal savings or standard bank lending.
Are Zook Cabin’s ADUs Built to Code?
Every Zook Cabins ADU is manufactured to high residential standards and engineered to align with Indiana’s building regulations. Our team is well-versed in local permitting requirements, designing each unit to ensure that safety codes and zoning expectations are met from the start. From the structural frame to the interior finishes, we focus on providing high-quality dwellings that allow for a smooth and efficient approval process with your building department.
Can an ADU Have Multiple Bedrooms and Bathrooms?
Yes, in Indiana, an accessory dwelling unit is permitted to have more than one bedroom or bathroom, provided the design stays within the size constraints set by your local municipality. Since these regulations are managed at the local level, it is important to check the specific room and floor area limits for your city or county.
Many Indiana communities allow for units with one or two bedrooms as long as the total square footage does not exceed the local cap, which often ranges between 800 and 1,000 square feet. This flexibility makes multi-room designs like the Grove, Luna, or A-Frame excellent options for property owners who need extra space while still meeting local residential standards.
Are ADUs A Good Investment?
Building an accessory dwelling unit is a strategic investment for Indiana property owners. These structures offer the unique ability to produce reliable rental income, raise the overall market value of your real estate, and provide a flexible space for multi-generational living or lifestyle shifts.
In Indiana’s growing markets, such as Indianapolis or the surrounding suburbs, homeowners often see a significant boost in equity after completing an ADU. Because the land is already owned, the potential return on investment for a rental unit is particularly high, helping to offset mortgage costs or fund retirement. Whether your goal is to house aging family members nearby or to build long-term wealth through a secondary suite, an ADU remains one of the most effective ways to maximize the utility and value of your Indiana property.
What Counties in Indiana Allow ADUs?
Does Adams County, Indiana, Allow ADUs?
Yes, you are allowed to build an accessory dwelling unit in Adams County, where they are classified as secondary residential structures on a lot with an existing primary home. All construction must comply with the 2020 Indiana Residential Code, requiring a permanent foundation and fixed utility hookups. For smaller units under 400 square feet, the county applies Appendix Q standards, which allow for more flexible loft and stair designs. Before construction, an Improvement Location Permit is required to ensure the unit meets all setback and flood map requirements.
Does Allen County, Indiana, Allow ADUs?
You are permitted to add an ADU in Allen County under 2025 regulations that cap the size of the unit at 700 square feet of gross floor area. To be legally recognized, the unit must include its own kitchen and bathroom, though the county explicitly prohibits using shipping containers or old vehicle bodies as dwellings. While integrated units are often permitted by right, freestanding ADUs in residential zones usually require a Special Use permit through a public hearing. The county has also eliminated minimum off-street parking requirements to make these units easier to build.
Does Bartholomew County, Indiana, Allow ADUs?
In Bartholomew County and the City of Columbus, accessory dwellings are allowed but are treated as conditional uses that require a case-by-case review. In residential districts, these units must be between 400 and 1,000 square feet and cannot exceed 65% of the primary home’s size. Agricultural zones offer more flexibility, allowing a unit to reach 75% of the main home’s area. All ADUs must share the existing driveway of the primary residence and be situated on a permanent foundation.
Does Benton County, Indiana, Allow ADUs?
Yes, Benton County allows for accessory dwelling units as long as they are on the same parcel as a legally established single-family home. Under the 2025 code, an ADU is restricted to a maximum of 900 square feet of habitable space and no more than two bedrooms. The structure must be built within 200 feet of the main house and utilize the same road approach. The county also mandates that either the main house or the ADU be occupied by the owner, and neither unit can be used as a short-term rental.
Does Blackford County, Indiana, Allow ADUs?
Blackford County permits the construction of accessory dwelling units, provided you secure an Improvement Location Permit from the Area Planning and Zoning office. You must submit detailed site and building plans for review, a process that generally takes about three business days. All residential units are subject to mandatory inspections to ensure they meet state building codes; buildings without a permit can lead to fines or a requirement to remove the structure. While minor interior remodeling is exempt, any new residential footprint must be fully permitted.
Does Boone County, Indiana, Allow ADUs?
In Boone County, accessory dwelling units are allowed as secondary living spaces on properties with an existing single-family residence. These units must contain a full kitchen and bathroom with a separate outside entrance and are assigned their own unique address. Depending on your specific zoning, the unit may be permitted by right or may require a special exception from the Board of Zoning Appeals. The county’s 2025 standards prioritize that the ADU remain subordinate in size and appearance to the primary home.
Does Brown County, Indiana, Allow ADUs?
Yes, you are allowed one accessory dwelling unit per lot in Brown County, with a required minimum size of 400 square feet. The maximum floor area is capped at the lesser of 1,300 square feet or 75% of the primary building’s total area. The unit must be supported by an approved sewage disposal system and must remain under the same ownership as the main house. While long-term rentals are allowed for periods of 31 days or more, Brown County explicitly prohibits using ADUs as short-term tourist rentals.
Does Carroll County, Indiana, Allow ADUs?
Carroll County allows accessory dwelling units as long as they strictly comply with the regulations of the specific zoning district. The county views these units as accessory uses that are customarily incidental and secondary to the main residence. No residential structure can be built or altered unless it meets local standards for safety, light, and air. It is highly recommended to contact the Zoning Administration Office to verify your lot’s eligibility and specific subdivision rules before beginning your project.
Does Cass County, Indiana, Allow ADUs?
In Cass County and the City of Logansport, accessory dwelling units are permitted as a way to increase local housing variety. To protect the character of existing neighborhoods, the county requires that there be no visible change to the exterior of a structure when an accessory apartment is added. All new construction or improvements must be officially permitted and must take local flood maps into account for safety. These units are designed to provide homeowners with extra income while maintaining the community’s single-family residential feel.
Does Clark County, Indiana, Allow ADUs?
Clark County permits accessory dwelling units, with specific rules based on whether you are in an urban growth area or a rural zone. In urban settings, you can build up to two ADUs per lot, provided they stay under 1,000 square feet. In rural areas, the unit must be attached to the primary home and is limited to 1,500 square feet or 40% of the main home’s area. All units require a building permit to ensure safety, and rural projects must get health department approval for septic and water connections.
Does Clay County, Indiana, Allow ADUs?
Yes, accessory dwelling units are permitted in Clay County, provided the primary residence is owner-occupied and homesteaded. Only one ADU is allowed per parcel, and it must be subordinate in location, height, and square footage to the main house. The unit’s floor area must be at least 375 square feet and cannot exceed 1,000 square feet or 40% of the primary dwelling’s area, whichever is smaller. Furthermore, the lot must be at least 15,000 square feet, and you are required to provide one off-street parking space specifically for the ADU.
Does Clinton County, Indiana, Allow ADUs?
In Clinton County, you are allowed to build an accessory dwelling unit, though they are primarily regulated under “Medical Hardship” or “Family Care” provisions. These rules allow for a secondary unit to house a family member with documented medical needs, provided the structure does not alter the single-family appearance of the lot. All ADUs must contain a kitchen with a permanent stove and sink, as hotplates or microwaves are not recognized as acceptable substitutes. A critical local requirement is that the owner must occupy one of the two units, and the ADU must typically be removed if the specific occupant for whom it was built no longer resides there.
Does Crawford County, Indiana, Allow ADUs?
Accessory dwelling units are permitted in Crawford County under a November 2025 ordinance designed to promote diverse housing for students, seniors, and caregivers. ADUs are categorized as a special exception in AG, RE, and R1 through R4 zones and require Board of Zoning Appeals approval before a building permit can be issued. These units must have at least 400 square feet of living area and are capped at the lesser of 1,500 square feet or 50% of the main home’s footprint. The county requires ADUs to share the existing driveway of the primary home and prohibits them from being sold separately from the main property.
Does Daviess County, Indiana, Allow ADUs?
Yes, Daviess County allows for accessory dwelling units, and updated 2025 policies permit up to two detached ADUs on lots of one acre or more if at least one is designated as affordable housing. All units must have separate utility meters, including a dedicated city water meter that requires a new tap into the main line. While the ADU shares the same base address as the primary residence, it must use a “Unit 1” or “Unit 2” suffix for identification. To ensure structural safety, any off-site or modular ADU must be placed on a permanent, code-compliant foundation system and cannot be a mobile home or recreational vehicle.
Does Dearborn County, indiana, Allow ADUs?
You are permitted to build an accessory dwelling unit in Dearborn County as a subordinate structure that is incidental to the primary residence. In most residential districts, a detached ADU must meet a minimum living area of 950 square feet and be located at least 10 feet away from the main house. A Location Improvement Permit is mandatory for all new units, and if the property is not on a municipal sewer, the homeowner must provide proof from the Health Department that the land can support separate septic disposal. Additionally, these units are restricted by the same height limits as the primary dwelling and must adhere to 80-foot front-yard setbacks from the road centerline.
Does Decatur County, Indiana, Allow ADUs?
In Decatur County, accessory dwelling units are allowed and must contain independent facilities for sleeping, eating, cooking, and sanitation. The county restricts these units to a maximum of two bedrooms and a total floor area of 800 square feet, which cannot exceed 40% of the primary home’s size. Property owners must occupy either the main house or the ADU for at least eight months of the year and are prohibited from receiving rent for the unit they personally occupy. Before receiving a certificate of occupancy, the homeowner must record a sworn statement with the county affirming their intent to comply with these residency requirements.
Does DeKalb County, Indiana, Allow ADUs?
Homeowners in DeKalb County are allowed to add accessory dwelling units, which the county defines as secondary living spaces that must remain subordinate in size and appearance. An ADU here is capped at a maximum of 800 square feet or 50% of the main home’s heated floor area, whichever is less. To protect neighborhood character, the county requires the ADU to use similar materials, colors, and roof pitches as the primary residence and to be oriented so that entrances face away from the street. Furthermore, DeKalb County requires a minimum lease term of 30 days, effectively prohibiting the use of ADUs as short-term vacation rentals.
Does Delaware County, Indiana, Allow ADUs?
Yes, you are permitted to build an accessory dwelling unit in Delaware County, and all units 200 square feet or larger require a building permit from the Building Commissioner. The county mandates that all construction meet the standards of the Indiana Residential Code and requires that any electrical, plumbing, or HVAC work be performed by registered and bonded contractors. If a homeowner begins construction without these permits, they face an initial fine of $700 plus the cost of the necessary permits. After completion, a final inspection is required to notify the county assessor and ensure the structure is legally recorded on the property.
Does Dubois County, Indiana, Allow ADUs?
Accessory dwelling units are allowed in Dubois County and are a featured component of the county’s 2025 strategic approach to increasing housing variety. ADUs can be attached, detached, or integrated into an existing structure like a garage, provided they remain on the same parcel as the primary single-family home. All new units must meet the environmental health requirements for septic permits and safe water supply as managed by the County Health Department. Homeowners are encouraged to leverage recent housing study data to ensure their ADU project aligns with local goals for safe and affordable rental options.
Does Elkhart County, Indiana, Allow ADUs?
Yes, Elkhart County allows for accessory dwelling units, which are officially defined as second dwelling units with independent cooking, sleeping, and bathroom facilities. Under the current development ordinance, these units must be smaller than 700 square feet and cannot be sold or parceled off separately from the primary lot. Only one ADU is permitted per parcel, and it must comply with the same setback and location standards as any other accessory structure in that zoning district. Integrated units are permitted by right in all residential zones, while freestanding units are permitted in Agricultural, Estates, and Single-Family districts.
Does Fayette County, Indiana, Allow ADUs?
Fayette County allows for the creation of accessory dwelling units, provided they are developed on a parcel that already contains a primary single-family home. Following recent 2025 local updates, these units are recognized as small, independent living spaces that must include their own kitchen and bathroom facilities. To protect the single-family character of neighborhoods, Fayette County requires the ADU to be architecturally compatible with the main house and typically mandates that the property owner reside in one of the two units. Both attached and detached configurations are permitted in most residential zones, with new rules designed to eliminate unnecessary parking requirements for these secondary dwellings.
Does Floyd County, Indiana, Allow ADUs?
Yes, accessory dwelling units are permitted in Floyd County, though they are strictly regulated to ensure they remain subordinate in size and purpose to the primary residence. Under the 2025 land division and zoning ordinances, detached ADUs must be situated on a permanent foundation and are generally prohibited from being mobile or manufactured homes. The county requires a special use permit for any freestanding unit in a residential district, a process that includes a public hearing to evaluate potential impacts on neighboring properties. All new units must meet Indiana’s residential safety codes and receive health department clearance for septic or sewer capacity.
Does Fountain County, Indiana, Allow ADUs?
Fountain County allows accessory dwelling units as part of its 2025 unified development strategy to accommodate diverse living arrangements. These units can be detached structures, such as backyard cottages, or integrated within existing buildings like detached garages. The county has established a base height limit of 16 feet for detached ADUs, though this can be increased up to 18 feet for certain roof pitches that align with the primary home. To streamline the development process, Fountain County requires the local permitting agency to approve or deny a completed ADU application within 60 days, effectively removing discretionary reviews for these projects.
Does Franklin County, Indiana, Allow ADUs?
Accessory dwelling units are permitted in Franklin County, where they are defined as detached, self-contained, small dwellings that are incidental to a larger principal home. According to the 2025 zoning ordinance, an ADU can be a stand-alone structure or part of a detached garage on the same lot. While these units are allowed, they must be smaller than the principal building in terms of square footage, height, and economic importance. In the City of Franklin, the Board of Zoning Appeals recently approved special-exception permits for ADUs of approximately 600 square feet, provided they meet specific design and parking conditions.
Does Fulton County, Indiana, Allow ADUs?
Yes, accessory dwelling units are permitted in Fulton County, where they are officially recognized in AG, RE, and R1 through R4 zoning districts. To build an ADU here, you must obtain a special exception from the Board of Zoning Appeals and a subsequent building permit. The unit must be at least 400 square feet and cannot exceed 1,500 square feet or 50% of the primary dwelling’s footprint. Furthermore, the county requires the ADU to use the same driveway as the main house and mandates that the property owner occupy either the primary or secondary dwelling.
Does Gibson County, Indiana, Allow ADUs?
Gibson County allows for the establishment of accessory dwelling units, provided they comply with the county’s subdivision and residential standards. While the county has repealed some broader land-use zoning in certain areas, all new dwellings must still be officially permitted and meet the Indiana Residential Code for structural safety. For properties using private septic systems, the Health Department must approve the additional waste load before a secondary unit can be built. Homeowners should consult with the County Commissioners’ office to verify if their specific township has localized zoning restrictions that would affect an ADU project.
Does Grant County, Indiana, Allow ADUs?
Accessory dwelling units are allowed in Grant County and are permitted by right in any zoning district that allows for single-family homes. Homeowners have the option of adding one internal ADU within the existing house and one detached unit, or simply one detached unit alone. All ADUs in Grant County must be used as permanent residences and are strictly prohibited from being rented out as short-term transient units. Additionally, detached units must be located on the lot so that the distance from the structure to any property line is at least 100 percent of the facility’s height.
Does Greene County, Indiana, Allow ADUs?
Greene County allows for the construction of accessory dwelling units, provided they meet the standards set by the local building commissioner and the Health Department. A permit is mandatory for any owner intending to construct, alter, or move a residential structure, as well as for the installation of essential utility systems. While unincorporated areas of Greene County often lack a blanket zoning map, any structure intended for human habitation must still be built to the state’s residential safety code. For projects within municipal boundaries, such as those in Bloomfield or Linton, additional local zoning and utility hookup rules will apply.
Does Hamilton County, Indiana, Allow ADUs?
Yes, you are permitted to build an accessory dwelling unit in Hamilton County, where they are often categorized as temporary apartments within owner-occupied single-family homes. An ADU here must not exceed 1,000 square feet or one-third of the total residential area of the property, whichever is less. These units are restricted to one bedroom and a maximum of two tenants, and the external appearance of the primary building must remain that of a single-family home. Notably, the county requires that kitchen facilities in these units be of a type that is “readily removable,” reflecting their intended use as flexible or temporary living quarters.
Does Hancock County, Indiana, Allow ADUs?
Hancock County allows for accessory dwelling units as a permitted secondary use on residential lots, with 2025 technical amendments further refining these rules. Integrated ADUs are allowed by right in various zoning districts, including AR, R1, R2, R3, and MHS. Freestanding ADUs are also permitted as accessory structures, though their placement is subject to specific development standards regarding the number of buildings per lot. All units must meet residential building codes, and any project involving the conversion of an existing accessory structure into a dwelling must be officially recorded to ensure compliance with height and setback limits.
Does Harrison County, Indiana, Allow ADUs?
Yes, you are permitted to build an accessory dwelling unit in Harrison County, provided the structure meets the minimum safety and health standards established in the zoning ordinance amended in September 2025. All new residential construction requires an “Application for Building Permit” submitted to the County Planner’s Office, and the project must adhere to the performance standards applicable to its specific district. While the county allows boarding houses with up to two rental rooms, a full ADU must be secondary to the primary home and may require a special exception or variance if it deviates from standard dimensional requirements. Homeowners are encouraged to use the local GIS system to verify parcel boundaries and ensure the unit respects the necessary setbacks from roads and easements.
Does Hendricks County, Indiana, Allow ADUs?
In Hendricks County, accessory dwelling units (referred to as accessory apartments) are allowed and must be constructed to maintain the single-family appearance of the property. The owner of the lot must occupy at least one of the dwelling units on the premises as their primary residence. According to current 2025 standards, an ADU cannot exceed 720 square feet or 75% of the primary dwelling’s footprint, whichever is greater, and must be built closer to the main house than to any property line. Furthermore, the county requires at least two off-street parking spaces for the property, and a screening plan must be included with the special exception application.
Does Henry County, Indiana, Allow ADUs?
Homeowners in Henry County are allowed to establish accessory dwelling units as long as the structure provides independent facilities for sleeping, eating, cooking, and sanitation on the same lot as a principal home. Under the 2025 revised law, a municipality may not limit an ADU to less than 750 square feet, and the total living space typically cannot exceed 950 square feet without special authorization. Henry County prevents local agencies from requiring familial relationships between occupants or limiting the unit to only one bedroom. To ensure legal compliance, all ADUs must be secondary in function and cannot be sold separately from the primary residence.
Does Howard County, Indiana, Allow ADUs?
Yes, you are permitted to build an accessory dwelling unit in Howard County, where they are managed through Improvement Location Permits rather than the specific by-right “ADU” laws found in more urbanized states. According to the Howard County Zoning Ordinance, accessory structures for habitation must be situated on a permanent foundation and must meet all setbacks for the primary residence in your specific district (e.g., a 5-foot side yard setback in R1 zones).
If your property is outside of Kokomo’s city limits and uses a private septic system, you must secure a Septic System Permit from the Howard County Health Department before any residential expansion is approved. Furthermore, all residential units must comply with the Indiana Residential Code, which requires structures intended for permanent living to have fixed utility hookups and meet specific life-safety standards for light and ventilation.
Does Jackson County, Indiana, Allow ADUs?
Yes, you are allowed to build a secondary residence in Jackson County, though the local zoning code typically classifies these as “Accessory Buildings with Living Quarters” or guest houses rather than under a standalone ADU law. Under the 2025 General Provisions, no parcel in the unincorporated county may contain more than one residential structure unless a specific temporary occupancy permit or a permanent variance is granted by the Board of Zoning Appeals.
For a secondary unit to be approved as a permanent addition, it must be established on an approved foundation and meet the full criteria of the 2020 Indiana Residential Code. All new habitable structures require an Improvement Location Permit and must obtain a separate on-site sewage permit from the Jackson County Health Department to ensure the septic system can handle the additional load. Furthermore, any secondary dwelling must adhere to the same front, side, and rear setbacks required for the primary residence in your specific zoning district.
Does Jasper County, Indiana, Allow ADUs?
Yes, accessory dwelling units (ADUs) are permitted in Jasper County under the 20.50.035 AD-01 standards, which apply to zoning districts A1, A2, R1, and R2. In these areas, you can build a unit as small as 220 square feet, but it cannot exceed 800 square feet or the ground floor area of your primary house, whichever is less. For detached units, the maximum height is capped at 25 feet or the height of your main house, whichever is lower. The county requires the ADU to match the architectural style, materials, and colors of your primary residence, and it must maintain a single physical address with a separate unit number (e.g., Unit 101). Notably, Jasper County explicitly prohibits using an ADU as a short-term rental, meaning it must be used for long-term residency.
Does Jay County, Indiana, allow ADUs?
Jay County allows for accessory dwelling units, and as of June 2025, all applications for projects requiring Plan Commission or Board of Zoning Appeals approval must be submitted via an online permitting system. The county’s staff maintains the right to enter premises at reasonable times to perform inspections and ensure compliance with the local zoning ordinance. All projects must meet the safety standards of the Indiana Code to ensure the dwelling is legally fit for habitation.
Does Jefferson County, Indiana, Allow ADUs?
In Jefferson County, accessory dwelling units are allowed as separate, complete housekeeping units limited to two bedrooms. Detached ADUs must be situated within 100 feet of the primary structure on mountain lots and must follow the same driveway as the main home. The maximum size of an ADU is typically 1,200 square feet or 40% of the primary unit’s size, whichever is less, though any ADU may be at least 500 square feet. The county requires that the property owner occupy one of the units as their primary residence and mandates one additional off-street parking space for each bedroom in the ADU.
Does Jennings County, Indiana, Allow ADUs?
Jennings County permits accessory dwelling units, with 2025 updates focusing on streamlining the permitting process for multi-family and detached structures. Property owners are now able to add up to eight detached ADUs on multi-family lots, provided the number of new units does not exceed the existing units on the property. If you are converting uncovered parking spaces to build an ADU, local agencies can no longer require you to replace those parking spots. All units must meet the definition of “livable space,” which includes dedicated areas for sleeping, cooking, and sanitation intended for human habitation.
Does Johnson County, Indiana, Allow ADUs?
Yes, accessory dwelling units are permitted in the unincorporated areas of Johnson County, provided they are established on the same lot as an existing single-family home. Under the 2025 Code of Ordinances, these units must meet the structural and safety standards of the Indiana Residential Code and are subject to local building permits and inspections. For properties located within White River Township, new residential developments, including ADUs, are assessed a specific Road Impact Fee at the time the building permit is issued. Homeowners must ensure the unit respects all zoning setbacks and does not exceed the allowed lot coverage for their specific residential district.
Does Knox County, Indiana, Allow ADUs?
In Knox County, you are allowed to build an accessory dwelling unit, but it must be clearly subordinate to the primary residence in both size and function. Following state-aligned 2025 standards, these units must provide independent facilities for sleeping, eating, cooking, and sanitation on the same parcel as the principal home. A municipality within the county may not limit the size of an ADU to less than 750 square feet, and the total living space generally cannot exceed 950 square feet unless a special local authorization is granted. Additionally, Knox County prohibits local agencies from requiring a familial relationship between the occupants of the ADU and those of the primary dwelling.
Does Kosciusko County, Indiana, Allow ADUs?
Yes, accessory dwelling units are permitted in Kosciusko County, where the local government has adopted objective development standards for 2025 to streamline the review process. These standards ensure that approvals involve no subjective judgment and are verified strictly by external benchmarks such as height and area. Detached ADUs have a base height limitation of 16 feet, though this may be increased to align with the roof pitch of the primary home. The county is required to act on a completed ADU application within 60 days, and if a demolition of an existing uncovered parking spot is required for the build, those parking spaces do not need to be replaced.
Does LaGrange County, Indiana, Allow ADUs?
LaGrange County allows for the construction of accessory dwelling units, provided a principal residence already exists on the lot. Under the 2025 zoning rules, detached accessory structures used for habitation must be set back at least 10 feet from the main house and are limited to one story and 18 feet in height. All projects require a complete Improvement Location Permit application, which undergoes a multi-departmental review by Planning, Surveying, and Building officials. Homeowners should note that the county typically permits only one detached accessory building per lot, though smaller sheds or gazebos may be allowed in addition to the dwelling.
Does Lake County, Indiana, Allow ADUs?
In Lake County, accessory dwelling units are permitted as an accessory use to detached houses in the R-1 zoning district, provided the lot has a minimum area of 80,000 square feet. To build an ADU here, the structure must be subordinate to the primary home in terms of area and extent, and it must utilize a fully compliant well and septic system. While you may connect to the existing well if it is up to code, any increase in square footage over 50% or the addition of a bedroom often requires significant septic upgrades. Developers must ensure that new construction does not adversely impact neighboring properties through overland drainage runoff.
Does LaPorte County, Indiana, Allow ADUs?
Yes, you are permitted to build an accessory dwelling unit in LaPorte County, though many projects, such as converting a garage into living space for a family member, require a specific variance or special exception from the Board of Zoning Appeals. According to 2025 board decisions, these approvals often come with conditions, such as requiring separate electrical service and updated septic systems for the secondary unit. Homeowners must coordinate closely with the Building Commissioner to secure the necessary permits and schedule mandatory inspections. The county also strictly enforces setbacks for wetlands and waterways, which may require a formal delineation before construction can proceed.
Does Lawrence County, Indiana, Allow ADUs?
Lawrence County allows for the creation of accessory dwelling units, and as of June 2025, all applications for projects requiring Plan Commission or Board of Zoning Appeals approval must be submitted via an online portal. While the county manages a variety of land-use classifications, ADUs are viewed as a compatible residential accessory use that must adhere to local setbacks and utility requirements. Staff members have the right to enter premises at reasonable times to execute inspections and ensure compliance with the local zoning ordinance. If your property is in a rural area, you must also obtain Health Department clearance for any additional load on your septic system.
Does Madison County, Indiana, Allow ADUs?
In Madison County, you are allowed to establish an accessory dwelling unit, and the 2025 housing proposals have actively worked to remove administrative barriers for these secondary homes. Homeowners can now add an ADU by right in most residential districts, provided all lot size and placement rules are followed, without needing a conditional use permit. If you have a deep lot that is twice the required minimum size, you may even split the property to create a “backyard lot” for a new residence. All new ADUs must comply with established entrance and drive standards, which typically limit single-family residences to one shared driveway.
Does Marion County, Indiana, Allow ADUs?
Yes, accessory dwelling units are permitted throughout Marion County under the Consolidated City and County Code updated in May 2025. In most residential zones, an ADU must be secondary to the primary home and is subject to specific height and setback limits to preserve neighborhood consistency. The county requires that the property remain owner-occupied, meaning the owner must live in either the main house or the ADU. All units must meet the 2020 Indiana Residential Code and be officially recorded with the Department of Business and Neighborhood Services.
Does Marshall County, Indiana, Allow ADUs?
Yes, you can have an accessory dwelling unit in Marshall County, provided you obtain a Special Exception from the Board of Zoning Appeals. Under the 2025 ordinance, an ADU is defined as a separate dwelling on the same parcel as a primary home, and it must meet all the standard requirements of a single-family dwelling, including being placed on a permanent foundation. To secure your permit, you must demonstrate that the unit is “clearly incidental and secondary” to the main house and receive a Septic Permit from the Health Department, which often requires a separate or upgraded system to handle the second unit. While the county generally limits density to one home per five acres in rural A-1 zones, the zoning board has the authority to grant exceptions for ADUs intended for family care or guest housing.
Does Martin County, Indiana, Allow ADUs?
Yes, you are allowed to build an accessory dwelling unit in Martin County, though there is no single “ADU” ordinance; instead, all residential structures must comply with the Building Control Ordinance. All new dwellings, including secondary units, require a building permit and must be placed on a permanent foundation. The county requires that any new habitable structure meet the Indiana Residential Code and receive a Septic Permit from the local Health Department before an Improvement Location Permit is issued. In rural areas without local zoning maps, the state’s minimum standards for fire safety and sanitation act as the primary regulatory framework.
Does Miami County, Indiana, Allow ADUs?
In Miami County, accessory dwelling units are permitted, provided they are located on a lot that meets the minimum acreage requirements for multiple dwellings, often requiring significantly larger parcels if on private septic. All secondary units must receive an Improvement Location Permit to ensure they do not infringe on established agricultural setbacks or regulated drain easements. Under 2025 guidelines, any structure intended for long-term habitation must have fixed utility hookups and cannot be a mobile unit or RV. It is mandatory to coordinate with the Miami County Plan Commission in Peru to verify that your specific site plan doesn’t exceed the allowed lot coverage for your zoning district.
Does Monroe County, Indiana, Allow ADUs?
Yes, you are permitted to build an accessory dwelling unit in Monroe County, and the 2025 Unified Development Ordinance (UDO) actively encourages them to increase housing density. In Bloomington and unincorporated Monroe County, an ADU is capped at a maximum of 800 square feet or 35% of the primary home’s area, whichever is less. One of the two units on the property must be owner-occupied, and a deed restriction affirming this must be recorded with the County Recorder before the permit is finalized. The county also limits ADUs to two bedrooms and requires that the architectural design, including siding and roof pitch, remain compatible with the primary residence.
Does Montgomery County, Indiana, Allow ADUs?
Yes, you can build an accessory dwelling unit in Montgomery County, and the process is managed through the Building Administration office in Crawfordsville. To be compliant, any new residential structure, including an ADU, must meet the standards of the Indiana Residential Code and be situated on a permanent foundation. While the county allows secondary dwellings, you must first secure an Improvement Location Permit and a Septic Permit from the Health Department to prove the property can handle the additional wastewater load. Detached units must follow the specific setbacks for your zoning district, typically requiring a 10-foot side-yard clearance in residential areas.
Does Morgan County, Indiana, Allow ADUs?
Yes, accessory dwelling units are permitted in Morgan County as a subordinate residential use, provided they are located on a lot with an existing primary home. Under the 2025 guidelines, the county allows one ADU per parcel, and it can be attached to the main house or freestanding. For detached units, the county requires the structure to be architecturally consistent with the primary home and limits the height to 25 feet or the height of the main house, whichever is lower. It is important to note that the primary dwelling must be owner-occupied, and the ADU cannot be sold as a separate property.
Does Newton County, Indiana, Allow ADUs?
Yes, you are allowed to establish an accessory dwelling unit in Newton County, where they are officially recognized in agricultural and residential zoning districts. All new habitable structures require an Improvement Location Permit and must meet state-mandated fire and safety standards. Because much of Newton County is rural, the most critical step is obtaining Health Department approval for an expanded septic system before construction begins. If you are building within the 2-mile buffer of a town like Kentland or Morocco, you may be subject to additional municipal design reviews.
Does Noble County, Indiana, Allow ADUs?
Yes, accessory dwelling units are permitted in Noble County, and the 2025 Unified Development Ordinance classifies them as “Secondary Dwellings”. These units are allowed by right in the A1, RE, and R1 zones, provided they do not exceed 900 square feet or 50% of the primary home’s floor area. Noble County requires that both units share the same driveway and utility connections whenever possible to maintain the single-family appearance of the lot. Furthermore, if the property uses a private well, the water quality must be tested and approved for the additional residence.
Does Ohio County, Indiana, Allow ADUs?
Yes, you can build an accessory dwelling unit in Ohio County, though the regulations are primarily centered around the Building Commission’s safety standards. All secondary dwellings must be built on a permanent foundation and meet the 2020 Indiana Residential Code. In the City of Rising Sun and surrounding unincorporated areas, you must verify that your ADU does not exceed the maximum lot coverage allowed for your specific parcel. Permits are required for all structural, electrical, and plumbing work, and final occupancy is only granted after a successful building inspection.
Does Orange County, Indiana, Allow ADUs?
Yes, accessory dwelling units are allowed in Orange County, and the county does not currently enforce a blanket zoning map in many unincorporated rural areas. This means you have significant flexibility in placement, provided you obtain a Septic Permit from the Health Department and follow state building codes for habitability. However, if your property is within the jurisdictional limits of Paoli, French Lick, or West Baden Springs, you must comply with their specific local zoning setbacks and size restrictions.
Does Owen County, Indiana, Allow ADUs?
Yes, you are permitted to build an accessory dwelling unit in Owen County, where the Focus is on providing safe, code-compliant housing. All new residential construction requires a building permit from the Owen County Building Department and must be inspected at various stages of completion. While the county is relatively permissive regarding ADU size, any structure used as a dwelling must have a permanent heat source and a fully functional kitchen and bathroom. Homeowners are required to provide a site plan showing that the ADU will not interfere with existing utility easements or property lines.
Does Parke County, Indiana, Allow ADUs?
Yes, accessory dwelling units are permitted in Parke County, provided they adhere to the local building and health ordinances. All secondary residences require an Improvement Location Permit to ensure they meet the minimum setbacks from county roads and neighboring properties. For detached ADUs, the county requires a permanent foundation and strictly prohibits the use of recreational vehicles or campers as permanent secondary dwellings. If your land is located in a designated floodway near the Wabash River, additional permits may be required before you can break ground.
Does Perry County, Indiana, Allow ADUs?
Yes, you are allowed to build an accessory dwelling unit in Perry County, provided you obtain an Improvement Location Permit and pay the associated residential structure fees. For 2025, the county charges a base fee of $55 plus $0.10 per square foot for accessory structures and additions. To be compliant, any new residential unit must be placed on a permanent foundation and meet the state building code for structural and fire safety. If the property uses a private septic system, you must secure Health Department approval before the building permit is finalized to ensure the system can handle the additional dwelling.
Does Pike County, Indiana, Allow ADUs?
Yes, you can have an accessory dwelling unit in Pike County, though they are managed through the general residential development standards in the county’s zoning ordinance. All new dwellings, including secondary units, require a building permit and must be secondary to the primary home in terms of square footage and height. While the county is relatively permissive regarding rural residential growth, any structure intended for long-term habitation must be built on a permanent foundation and cannot be a mobile unit or camper. Homeowners should coordinate with the Area Plan Commission in Petersburg to verify specific setbacks from property lines and agricultural buffers.
Does Porter County, Indiana, Allow ADUs?
Yes, accessory dwelling units are permitted in Porter County, and for 2025, the Unified Development Ordinance (UDO) allows them as “subordinate residential structures”. In Rural Residential (RR) districts, detached accessory structures are typically limited to a maximum height of 20 feet, though you can apply for a development standards variance to increase this if needed. All ADUs must receive a building permit and must meet the specific floor area limits established for your zoning district. To protect the property value of neighboring homes, the county requires the unit to use architecturally compatible materials and maintain established setbacks.
Does Posey County, Indiana, Allow ADUs?
Yes, you are allowed to build an accessory dwelling unit in Posey County, where they are officially classified as structures “incidental and subordinate” to the principal dwelling. To begin, you must secure an Improvement Location Permit and, if the project is in a residential area, you may need a Special Use permit. The county is very specific about the type of building allowed: an ADU must be a permanent structure and must comply with the Federal Manufactured Housing Code or Indiana modular home standards; notably, Posey County does not allow recreational vehicles, campers, or non-permanent structures to be used as secondary dwellings.
Additionally, you must submit a plot plan to the Area Plan Commission showing that the unit respects all property setbacks and does not infringe on existing utility or drainage easements. If your property uses a private septic system, the Health Department must verify it can handle the additional residence before your building permit is finalized.
Does Pulaski County, Indiana, Allow ADUs?
Yes, you can build an accessory dwelling unit in Pulaski County, where they are officially defined as “mother-in-law apartments” or separate living spaces on the same property as an existing house. To move forward, you must secure an Improvement Location Permit and ensure the structure is “secondary to a primary use in area, extent, and purpose”. While the county allows these units, they must be situated on a permanent foundation and comply with the Indiana Residential Code regarding fire safety, light, and ventilation. Because Pulaski County prioritizes the preservation of rural character, any detached unit must follow the same building setbacks as the primary residence and receive Health Department approval for on-site sewage disposal before construction begins.
Does Putnam County, Indiana, Allow ADUs?
Yes, you can build an accessory dwelling unit in Putnam County, following a November 2025 ordinance that established specific standards for ADUs. These units are allowed by Special Exception in AG, RE, and R1 through R4 zones and must contain a minimum of 400 square feet. The maximum size is restricted to 1,500 square feet or 50% of the primary home’s footprint. According to the new rules, the property owner must live in either the main house or the ADU, and both units must share the same existing driveway.
Does Randolph County, Indiana, Allow ADUs?
Yes, you are permitted to have an accessory dwelling unit in Randolph County, and the process begins by securing an Improvement Location Permit (ILP) from the Area Planning office. Even portable pre-built sheds intended for habitation require an ILP and a subsequent building permit. The county updated its Unified Zoning Ordinance in December 2025 to ensure that all secondary structures meet current floodway and subdivision control standards. It is mandatory to consult the updated zoning map to verify the specific setbacks and lot coverage limits for your parcel before starting construction.
Does Ripley County, Indiana, Allow ADUs?
Yes, accessory dwelling units are allowed in Ripley County, and the Area Planning & Building department provides a standardized application for Improvement Location Permits. All secondary dwellings must meet the state’s residential building code and are subject to the county’s fee schedule for new residential construction. While Ripley County has specific rules for when RVs can be used for temporary occupancy, any permanent ADU must be on a code-compliant foundation with fixed utility hookups. Homeowners should check the 2026 meeting schedule if their project requires a hearing with the Board of Zoning Appeals for a special exception.
Does Rush County, Indiana, Allow ADUs?
Yes, you can build an accessory dwelling unit in Rush County and the City of Rushville, where 2025 zoning ordinances are designed to promote healthful surroundings for family life. All new construction, including structural alterations to place a building on a foundation, requires an Improvement Location Permit. The county focuses on ensuring that secondary dwellings provide adequate safety from fire and flood, particularly for properties near established flood hazard areas. To be compliant, an ADU must be incidental to the primary home and meet all local standards for light and air.
Does St. Joseph County, Indiana, Allow ADUs?
Yes, accessory dwelling units are permitted in St. Joseph County, and they are defined as secondary structures that support the primary residential use of the lot. Attached units must have a total floor area less than the main floor area of the primary dwelling unit. For detached units, the size is capped at 1,200 square feet or less than the main floor area of the primary building. Detached ADUs must be located behind the established front building line and require an Improvement Location Permit before any site work begins.
Does Scott County, Indiana, Allow ADUs?
Yes, you can build an accessory dwelling unit in Scott County under Ordinance 2025-05, which was adopted in November 2025 to expand housing options. These units are permitted by Special Exception in the AG, RE, and R1 through R4 zones. Your ADU must be at least 400 square feet and is capped at the lesser of 1,500 square feet or 50% of the primary home’s footprint. The county requires the ADU to be located behind the front facade of the main house and mandates that the property owner occupy one of the two units.
Does Shelby County, Indiana, Allow ADUs?
Yes, you are permitted to have an accessory dwelling unit in Shelby County, and the county is currently updating its Unified Development Ordinance (UDO) in late 2025 to further streamline these approvals. All new habitable structures require an Improvement Location Permit and must meet the Indiana Residential Code for structural safety. For properties outside of city limits, you must obtain a permit from the Shelby County Plan Commission and verify that your on-site septic system can accommodate the additional residence.
Does Spencer County, Indiana, Allow ADUs?
Yes, you can build an accessory dwelling unit in Spencer County, where the process is managed through the Plan Commission and Building Inspector. All secondary residences require a building permit and must be situated on a permanent foundation. If your project involves a change in the primary use of the property, you may need to petition for a rezoning or a special exception, which carries a $50 filing fee. The county enforces strict setbacks for new construction, and any project near the Ohio River must also consider floodplain management rules.
Does Starke County, Indiana, Allow ADUs?
Yes, accessory dwelling units are permitted in Starke County, and for 2025, they are recognized as a way to provide “secondary housing” on the same lot as a primary home. An ADU in Starke County should generally range between 220 and 800 square feet and cannot exceed 50% of the primary dwelling’s living space. To be legal, the unit must have independent facilities for cooking, sleeping, and sanitation, and must be officially permitted by the county planning commission.
Does Steuben County, Indiana, Allow ADUs?
Yes, you are allowed to build an accessory dwelling unit in Steuben County, where the 2025 Zoning Ordinance (Chapter 11) governs their construction. Detached accessory buildings used as dwellings are limited to one story and a maximum height of 18 feet. The county allows these units, provided they are secondary to the primary home, and any plumbing for sewer or water must be pre-approved by the Health Department. You are generally limited to one detached accessory building on lots less than two acres.
Does Sullivan County, Indiana, Allow ADUs?
Yes, you can establish an accessory dwelling unit in Sullivan County, following the standards of the Indiana Residential Code. All new dwellings require an Improvement Location Permit and must be placed on a permanent foundation. Because much of the county is rural, the Health Department must verify that your property has adequate acreage and septic capacity for a second residence before a building permit is issued.
Does Switzerland County, Indiana, Allow ADUs?
Yes, accessory dwelling units are allowed in Switzerland County, where the Area Zoning Code permits secondary residences that conform to district standards. A detached ADU must be smaller than the main floor area of the primary house, and you are typically limited to one detached accessory building per lot. If you are building in the A-1 Prime Agriculture District, you must ensure the unit meets the 40-foot front-yard setback from the road right-of-way.
Does Tippecanoe County, Indiana, Allow ADUs?
Yes, you can have an accessory dwelling unit in unincorporated Tippecanoe County, following the passage of Ordinance 2025-06 in March 2025. The ordinance allows for internal, attached, and detached ADUs between 400 and 750 square feet. Note that while the county and the City of Lafayette have approved ADUs, the City of West Lafayette rejected them in early 2025, so you must confirm your specific municipal jurisdiction. All units must be owner-occupied, and plumbing must tie into the primary residence’s service.
Does Tipton County, Indiana, Allow ADUs?
Yes, you are permitted to build an accessory dwelling unit in Tipton County under the 2025 ADU Ordinance (CO-ZO-24-25). The county allows for the division of a single lot from an existing tract for a new dwelling without a formal subdivision process, provided it meets all zoning setbacks. All ADUs require an Improvement Location Permit and must comply with the 2025 technical standards for sanitation and access.
Does Union County, Indiana, Allow ADUs?
Yes, accessory dwelling units are allowed in Union County, but they are approved as a Conditional Use and require a public hearing. Under the 2025 standards, your lot must be two acres or greater, and the ADU cannot be located more than 100 feet from the existing house. The unit is limited to 900 square feet of usable floor space and cannot be used as a short-term rental. There is a $300 application fee for the conditional use permit.
Does Vanderburgh County, Indiana, Allow ADUs?
Accessory dwelling units are officially permitted in Vanderburgh County under Section 17.12.072 of the general zoning standards. These units must fall between 400 and 800 square feet, though you can build up to 40% of your main house’s floor area if that total is larger. To move forward, you must sign an affidavit confirming that the property owner will live in either the primary residence or the ADU. The county requires the unit to be on a permanent foundation and strictly prohibits the use of shipping containers, mobile homes, or RVs as habitable spaces.
Does Vermillion County, Indiana, Allow ADUs?
Accessory dwelling units are allowed in Vermillion County once you have secured the proper health and building permits from the Newport office. For 2025, you must first obtain a septic system permit from the Health Department to prove your lot can handle the additional waste. Following this, you can apply for an Improvement Location Permit ($135) to authorize the construction. The county mandates that the unit provide its own off-street parking and adhere to all local setbacks to protect neighboring properties.
Does Vigo County, Indiana, Allow ADUs?
Accessory dwelling units are permitted in Vigo County as a strategy to provide diverse housing choices in established neighborhoods. Under the ThriVe 2025 framework, the county encourages these units as “infill” development to reduce urban sprawl. While some projects may be permitted by right, many freestanding units require a Special Use approval from the Board of Zoning Appeals to ensure they fit the architectural heritage of the area. The county also prioritizes units that have easy access to public transit or existing walking infrastructure.
Does Wabash County, Indiana, Allow ADUs?
Accessory dwelling units are authorized in Wabash County as long as you obtain the required Improvement Location Permit prior to placement. The 2023–2025 Zoning Ordinance explicitly states that no residential structure, including those categorized as “portable” but intended for living, can be erected without this official approval. You must submit a site plan showing that the unit is subordinate to the primary home and meets all district-specific setbacks. The county also requires all habitable units to meet state fire and safety standards for permanent dwellings.
Does Warren County, Indiana, Allow ADUs?
Accessory dwelling units can be built in Warren County thanks to the modern standards established in the Z2025-05-01 zoning amendment. This update specifically replaced outdated “guesthouse” language to allow for more flexible secondary living spaces on a single lot. Your ADU must remain incidental to the primary residence and comply with the joint zoning rules shared by the county and its cities. To be approved, you must demonstrate that the unit has adequate safety access and does not infringe on existing utility easements.
Does Warrick County, Indiana, Allow ADUs?
Accessory dwelling units are a valid residential option in Warrick County, provided they comply with the Unified Development Ordinance (UDO). The county’s building department manages the process, requiring digital house plans to be submitted for structural review. For 2025, any detached ADU must meet the same height and setback restrictions as other accessory buildings in your zoning district. Additionally, you must verify with the health department that your septic or sewer connection is rated for the additional capacity before breaking ground.
Does Washington County, Indiana, Allow ADUs?
Accessory dwelling units are permitted in Washington County, with 2025 regulations focusing on safe rental and occupancy standards. If you intend to use the ADU as a rental, you must register the unit and pass a mandatory safety inspection. All new construction requires a building permit from the local commissioner, with fees calculated based on the square footage of the structure. In rural areas, the Health Department must authorize your septic system installation before the unit can be legally occupied.
Does Wayne County, Indiana, Allow ADUs?
Accessory dwelling units are allowed in Wayne County, where they are managed by the Advisory Plan Commission as secondary residential structures. Recent 2025 updates in many Low Intensity Residential (AR) zones now allow two detached dwellings on a single lot by right, removing the need for a public hearing. However, the unit must still meet the definition of a “Guest House,” meaning it cannot be sold separately from the primary property. All units must meet the 2020 Indiana Residential Code and be situated on a permanent foundation.
Does Wells County, Indiana, Allow ADUs?
Accessory dwelling units are permitted in Wells County under the comprehensive zoning ordinance that went into effect on August 4, 2025. These units must be detached and are capped between 250 and 850 square feet. To maintain the character of the community, the ADU must share a mailbox and address with the primary home and use consistent architectural materials. The county mandates that the property owner reside on-site and that the unit contains no more than three rooms, excluding the bathroom.
Does White County, Indiana, Allow ADUs?
Accessory dwelling units are authorized in White County, and you can apply for the necessary permits through their 2025 online portal. To be approved, you must submit a dimensional survey from a registered land surveyor that identifies all improvements, wells, and septic systems on the property. If your ADU requires a deviation from standard size or height limits, you must file a Variance application and appear before the Board of Zoning Appeals. The county focuses on ensuring that any new residential structure does not negatively impact drainage or public safety.
Does Whitley County, Indiana, Allow ADUs?
Accessory dwelling units are possible in Whitley County by obtaining a Special Exception and a subsequent building permit. For 2025, the filing fee for a residential special exception is $240, while the Improvement Location Permit carries a $50 base fee. All habitable structures must comply with Indiana’s life-safety building codes, and the county performs multiple inspections to ensure quality construction. It is essential to secure all permits before any site work, such as foundation pouring, begins.
Accessory Dwelling Unit Requirements by Municipalities
Does Indianapolis, Indiana, Allow ADUs?
Accessory dwelling units are permitted citywide in Indianapolis as secondary housing on lots with an existing primary home. Under the 2025 standards, these units must range from 220 to 800 square feet and cannot exceed 50% of the primary dwelling’s living space. The city requires that the property remain owner-occupied, and the ADU must be connected to municipal water and sewer lines wherever available. All new units must match the visual harmony of the neighborhood and are subject to rigorous safety inspections before a final occupancy permit is issued.
Does Fort Wayne, Indiana, Allow ADUs?
Accessory dwelling units are now allowed by right in several zoning districts following the “Housing Options” amendments that took effect on November 7, 2025. In the AR, R2, and RP districts, you can now build a secondary detached dwelling without needing a public hearing or a special use permit. For R1 zones, freestanding ADUs are still permitted but require a Special Use approval from the Board of Zoning Appeals. The city has also removed minimum parking requirements for these units to make construction more affordable for homeowners.
Does Evansville, Indiana, Allow ADUs?
Accessory dwelling units can be built in Evansville, provided you first secure an Improvement Location Permit from the Area Plan Commission. All secondary residential structures are governed by the joint city-county zoning ordinance, which requires that any new unit meet current setback and green space standards. If your specific zoning district does not list secondary dwellings as a permitted use, you may need to file for a rezoning or a variance through the planning staff. Construction must always follow the 2020 Indiana Residential Code to ensure habitability.
Does South Bend, Indiana, Allow ADUs?
Accessory dwelling units are authorized in South Bend as subordinate structures that can be either attached to or detached from the main house. The 2025 regulations cap the size of an ADU at the lesser of 800 square feet or 75% of the primary home’s finished floor area. To be compliant, the unit cannot be taller than the main house and must meet all height requirements for its specific district. Additionally, in the S1, U1, and U2 districts, the owner is required to live on-site in one of the two units.
Does Carmel, Indiana, Allow ADUs?
Accessory dwelling units are permitted in Carmel, and the city is currently finalizing a draft ordinance to align local rules with 2025 state-level housing mandates. Until the new city code is fully ratified, the city planning department provides “ministerial” approval based on state guidelines. The 2025 draft standards focus on objective design requirements to ensure ADUs match the high architectural quality of Carmel neighborhoods. All new units require a building permit and must obtain a certificate of occupancy prior to being inhabited.
Does Fishers, Indiana, Allow ADUs?
Accessory dwelling units are allowed in Fishers, but they are subject to a new 2025 Rental Permit Cap if you intend to use them as long-term rentals. Under Chapter 163 of the City Code, any rental unit, including an ADU, must be registered by December 31, 2025, to be grandfathered into neighborhoods that may soon hit a 10% rental limit. Before construction, you must attend a pre-filing meeting with a city planner to discuss site work and architectural approval. The city requires that all ADUs remain secondary in size and function to the principal dwelling.
Does Bloomington, Indiana, Allow ADUs?
Accessory dwelling units are permitted in Bloomington on any property that contains a single-family or duplex dwelling. The 2025 Unified Development Ordinance (UDO) allows units up to 840 square feet with a maximum of two bedrooms. One unique requirement here is that the owner must record a deed restriction ensuring the ADU is never sold separately from the primary house. Detached ADUs must be situated behind the main house and are limited to a maximum height of 25 feet.
Does Hammond, Indiana, Allow ADUs?
Accessory dwelling units can be established in Hammond, but they must be registered annually as rental units if not occupied by the owner. The city charges a $5 annual registration fee per unit and enforces strict penalties of up to $2,500 per day for failure to register. While the city focuses heavily on code enforcement for rental safety, any new construction must also meet standard zoning variances if you intend to house non-related residents. All units must be maintained in a safe, habitable condition according to the city’s inspections department.
Does Lafayette, Indiana, Allow ADUs?
Accessory dwelling units are permitted citywide in Lafayette after the city expanded their use beyond the “Old Town” district in late 2023. Current 2025 regulations have further streamlined the process by eliminating parking requirements and removing several restrictive design standards. Both attached/interior and detached ADUs are allowed in most areas where single-family homes are found. These units are officially viewed as “mother-in-law suites” or carriage houses and must include a full kitchen and bathroom.
Does Noblesville, Indiana, Allow ADUs?
Accessory dwelling units are authorized in Noblesville as secondary living spaces, provided they have separate utility meters for water and electricity. According to the June 2025 policy update, ADUs will share the same street address as the primary home but must use a “Unit 1” or “Unit 2” suffix. The city allows one attached and one detached ADU per lot, or up to two detached units if the lot is over one acre and one unit is designated as affordable housing. No ADU may be sold separately from the main house, and mobile homes are strictly prohibited.
Does Gary, Indiana, Allow ADUs?
Accessory dwelling units can be built in Gary as part of the city’s 2025 Comprehensive Plan to revitalize the “Broadway District” and “University Park.” The city’s Planning Commission holds monthly hearings to review new residential developments that align with the updated Master Plan. While the city is currently drafting a new Unified Development Ordinance, all current ADU projects must meet state-mandated safety requirements and be compatible with the Gary Lakefront District standards if located near the shore.
Does Muncie, Indiana, Allow ADUs?
Accessory dwelling units are allowed in Muncie, and the city updated its Code of Ordinances in July 2025 to manage residential growth. All new secondary dwellings require a building permit and must follow the structural guidelines of the 2020 Indiana Residential Code. The city focuses on ensuring ADUs provide safe, independent living facilities while respecting the density limits of Muncie’s established residential zones. It is recommended to contact the building commissioner’s office to verify your specific lot’s setback requirements.
Does Greenwood, Indiana, Allow ADUs?
Accessory dwelling units are permitted in Greenwood as part of the 2025 state-aligned “Strategic Growth” initiative. Following recent legislative frameworks, the city must allow at least one ADU (internal, attached, or detached) on any lot where single-family homes are permitted. The review process for these units is now administrative, meaning they do not require a public hearing if they meet objective design standards. ADUs in Greenwood generally must fall between 500 and 750 square feet.
Does Kokomo, Indiana, Allow ADUs?
Accessory dwelling units are permitted in Kokomo and are governed by the 2025 Indiana Code standards for residential habitation. All secondary dwellings must be built on a permanent foundation and be connected to approved utility systems. To build an ADU here, you must obtain an Improvement Location Permit from the Howard County-Kokomo Plan Commission to ensure your project doesn’t interfere with local drainage or utility easements. The city mandates that any new units meet the life-safety requirements for light, air, and emergency egress.
Does Terre Haute, Indiana, Allow ADUs?
Accessory dwelling units are allowed in Terre Haute, but they must be registered and inspected under the city’s 2025 Safe and Habitable Premises ordinance. If an ADU is used as a rental, the owner must pay a registration fee and ensure the unit meets all electrical, fire, and building codes. Any unit that has multiple major code violations may be subject to an immediate $100 inspection fee and enforcement actions. For new construction, you must coordinate with the Department of Engineering to verify that your site plan respects all city setbacks and property maintenance rules.
Searching for an ADU Builder Serving Indiana?
Finding a builder you can trust is important. Whether you are envisioning a quiet woodland escape tucked into the rolling hills of Brown County, a sleek lakeside suite along the shores of Lake Wawasee, or a modern backyard cottage in the heart of Indianapolis, Zook Cabins is ready to bring that vision to life. We specialize in delivering code-compliant, high-performance structures to every corner of the Hoosier State. From the sand dunes of Michigan City to the scenic riverbanks of Evansville, our delivery network ensures your new home arrives safely at its destination.
Our team pairs advanced, precision-engineered manufacturing with a steadfast focus on the longevity your land deserves. We recognize that an Indiana home is more than just a structure; it is a sanctuary built to withstand the humid summers of the Wabash Valley and the heavy lake-effect snows of the north. We invite you to reach out today to consult with a specialist or receive a personalized quote. We pride ourselves on transparent pricing and dedicated customer support, guiding you from your very first inquiry to the moment you step onto your new porch to enjoy the Indiana sunset.
Tiny Homes & ADU Rules by State: How Do They Compare?
Indiana has carved out a unique path toward housing flexibility. Under 2025 updates to House Bill 1005, cities and counties that voluntarily modernize their zoning to allow accessory dwelling units and higher-density “missing middle” housing are moved to the front of the line for state infrastructure loans. This incentive has sparked a competitive race among Hoosier communities to adopt ADU-friendly ordinances.
The state’s 2025 regulatory environment is defined by a new commitment to permitting speed. For the first time, Indiana law now mandates that if a local building department is too backlogged to perform a plan review or inspection within a set window, typically seven business days for plans and two business days for inspections, the homeowner has the legal right to hire a certified private provider to keep the project moving. This “bypass” option ensures that backyard cottage projects in high-growth areas like Hamilton County or Hendricks County no longer get stuck in administrative limbo.
In terms of physical standards, most modern Indiana ordinances prioritize the “incidental” nature of the ADU. In jurisdictions like Fort Wayne and Allen County, 2025 technical amendments allow for freestanding units as a permitted use in many rural and suburban zones, typically capping them at 800 to 1,000 square feet. Many of these updated codes have also begun to strip away “poison pill” requirements, such as mandating extra garage spaces or using subjective design reviews that previously made ADUs financially unfeasible.
Conclusion…
Choosing the right builder for your home’s expansion is a huge step; it’s a decision that will shape your daily life for years to come. Here at Zook Cabins, we do more than just build; we craft incredible, high-performance homes perfectly suited for every corner of Indiana. Whether you’re on the rugged trails of the Knobstone Escarpment or near the quiet beauty of the Kankakee River, our team specializes in delivering complete, hassle-free residential solutions. We handle all the permits and ensure everything meets the strictest local rules.
If you dream of a charming cottage nestled among the southern hardwoods, or need a sleek, modern suite for your Indianapolis property, we promise a process that’s precise and completely transparent. We build homes tough enough to stand up to that humid Wabash summer heat and the sharp winter winds that sweep right across the Central Till Plain.