Imagine enjoying the bright sunny desert climate of Arizona with all its arid beauty and rugged mountains from the front porch of a luxury modular ADU. Accessory Dwelling Units are joining the tiny home movement and gaining popularity for their permanent foundations and larger (yet still compact) sizes. Luckily, with new state-wide legislation in Arizona, it has never been easier to start the process of installing your dream ADU on your property! Keep reading to discover the ins and out of modular ADUs and the specifics of owning one in Arizona.
Zook Cabins offers premium modular ADUs that can provide flexible housing options, multi-generational living, and an additional income source. Request a free quote today to start planning out your modular ADU!
Are ADUs Allowed in Arizona?
Yes! ADUs are now legally allowed throughout Arizona thanks to House Bill 2720, signed into law by Governor Katie Hobbs on May 21, 2024. Arizona cities with populations over 75,000 are now required to adopt regulations permitting at least one attached and one detached ADU on any lot zoned for single-family use. Lots that are one acre or larger must also permit a third detached ADU, if at least one unit is designated as income-restricted affordable housing.
This state law prohibits municipalities from imposing rules more restrictive than the state standard which means they cannot require additional parking, mandate matching exterior material, enforce owner‑occupancy relationships, mandate setbacks greater than 5 feet, or apply stricter height or lot‑coverage limits than those for the primary dwellings.
In short, Arizona now ensures that ADUs (often called casitas in Arizona) are broadly permitted in most single-family neighborhoods. This is great news for prospective ADU homeowners in Arizona who can benefit from these state guidelines. Keep reading to find out specific county guidelines for ADUs.
Can Park Model ADUs Be Used As ADUs?
Yes, in certain areas, park model homes will be permitted to use as ADUs. Arizona follows Appendix Q for all tiny homes which requires square footage less than 400 square feet and a permanent foundation.These tiny homes can qualify as an ADU, but explicit permission will have to be granted through your local zoning department.
Take a look at the table below to see what Arizona, and all the other states that we deliver to, have to say about tiny home regulations.
| AL | IL | MN | NC | TX |
| AZ | IN | MS | ND | UT |
| AR | IA | MO | OH | VT |
| CA | KS | MT | OK | VA |
| CO | KY | NE | OR | WA |
| CT | LA | NV | PA | WV |
| DE | ME | NH | RI | WI |
| FL | MD | NJ | SC | WY |
| GA | MA | NM | SD | |
| ID | MI | NY | TN |
Can Log Cabins Be Used As An ADU?
Yes, a prefab log cabin that is aligned with sizing requirements for your local municipality could be considered an ADU. To verify that a log cabin from Zook Cabins could be considered an ADU, reach out to your local building department.
What is the Difference Between a Prefab ADU & a Modular ADU?
Prefab ADUs are constructed fully in a factory then delivered and assembled as one unit. Prefab ADUs are popular for their easy delivery and convenience.
Modular ADUs, like the ones sold by Zook Cabins, are built in sections, then fully assembled on site. Instead of receiving the ADU in one finished building, the sections are put together to guarantee stability and to allow for any necessary adjustments on site. Modular ADUs are all built to the standards of a single-wide modular home.
Most local municipalities do not require one version or another when it comes to ADUs and either prefab or modular ADUs should be allowed wherever ADUs are permitted.
Can Modern Cabins Be Used As An ADU?
Yes, in some areas of Arizona, a modern cabin can be used for an ADU if it falls within the size and setback requirements. Some of the models from Zook Cabins are less than 1,000 square feet which would make them potentially eligible for ADU usage. For the most accurate information on modern cabins as ADUs, contact your local building and zoning departments.
What is the Minimum Size for an Accessory Dwelling Unit?
Arizona does not set a statewide minimum ADU size. However, municipal building codes and ADU regulations can impose local minimums. For example, Tucson explicitly requires that every lot be allowed an ADU of at least 650 square feet, with maximum size capped at 10 % of the lot area or 1,000 sq ft. Many jurisdictions also reference the IRC Appendix Q for tiny‑home standards, which sets a minimum interior floor area of about 296 sq ft and a minimum ceiling height of 6 ft 4 in.
Can My ADU be Bigger Than My House?
No. Under both Arizona state law and most municipal ADU regulations, an ADU cannot exceed 75 % of the gross floor area of the primary residence, or 1,000 sq ft on lots up to 10,000 sq ft, whichever is smaller. Larger lots may allow up to 10 % of the lot area in some cities like Phoenix. In summary, no Arizona jurisdiction permits an ADU larger than the main house.
How Close To My House Can I Build An ADU?
As of 2025, Arizona state law mandates minimum setbacks of five feet from both side and rear property lines, and five feet separation from any other structure on the lot. Local codes typically follow this baseline or default to the existing zoning. For example, in Phoenix, detached ADUs cannot be built closer than 5 feet to side and rear lines and 3 feet from an interior line. Attached ADUs must maintain at least 3 feet from the rear line and 5 feet from a side line, with height limited to 15 feet unless a special-use permit is obtained.
Do You Need A Permit For An ADU in Arizona?
Yes, no matter where you build or install your Arizona ADU, your local municipality will require several permits. Typically ADUs need a building permit, electrical and plumbing permits, and an HVAC permit. There are also other ADU permits that may pertain to your area, but the best way to find out the specific process is to contact your local building department.
Are There Any Incentives or Grants for ADUs in Arizona?
At this time, there are no state wide grants or incentives for buying or owning an ADU in Arizona. That said, with the recent legislation requiring larger municipalities to allow ADUs, state-wide grants may be in the future. Additionally, your local municipality may offer affordable housing grants or fee waivers, something worthwhile to at least inquire about. While ADUs are not technically in the traditional affordable housing category, some cities and towns can interpret them that way and give out a form of grant or incentive.
Are Zook Cabin’s ADUs Built to Code?
Yes, every single ADU from Zook Cabins is built to match and even exceed the local building codes. Our builders are both knowledgeable and experienced and we guarantee an accessory dwelling unit that is up to code in all areas.
Can an ADU Have Multiple Bedrooms and Bathrooms?
Absolutely! With some counties in Arizona allowing ADUs up to 1,000 square feet, you will have options for multi-bedroom ADUs and even multi-bathroom (although this is less common). Zook Cabins offers several 1 bedroom ADU models that are perfect for a single or couple starting off life in an ADU. We also design and sell several two bedroom models that may fit the needs of a small family better. Our Grove ADU has the option for two bedrooms and two bathrooms while still fitting under the 1,000 square foot size requirement in Arizona.
Are ADUs A Good Investment?
Tiny Homes For Airbnb | A-Frame Park Model Success Story | Zook Cabins
They sure are! ADUs are popular for a good reason; they offer flexible housing options while increasing your property value and investments. Depending on where you live, you could construct a detached ADU for only a couple hundred thousand and then rent it out long-term for $2-3,000 per month. That will give you a better ROI than a traditional house.
The potential for short-term rentals are also there, especially if you live in a popular tourism area where Airbnbs are needed. A beautiful modular ADU is appealing for people and you may find that your investment is earning you passive income in a powerful way. Plus, when you go to sell your property, you find that you can sell it for higher with the additional structure on the property. All together, ADUs are an excellent investment, but your specific ROI can vary on your location and zoning requirements.
The above video is a success story from a Zook Cabins client who used their tiny home as an Airbnb to bring in extra income. While ADUs differ from tiny homes, certain areas of Arizona will allow the use of park model homes as an ADU.
What Are the Requirements for ADUs in Each County in Arizona?
| Apache County | Community Development |
| Cochise | Planning and Zoning Department |
| Coconio County | Planning and Zoning Department |
| Gila County | Zoning Ordinances |
| Graham County | Planning and Zoning |
| Greenlee County | Zoning Ordinances |
| La Paz County | Planning and Zoning Commission |
| Maricopa County | Planning and Zoning Commission |
| Mohave County | Planning and Zoning Division |
| Navajo County | Planning and Development |
| Pima County | Planning and Zoning Commission |
| Pinal County | Planning Division |
| Santa Cruz County | ADU Regulations |
| Yavapai County | Development and Permits |
| Yuma County | Zoning Ordinances |
Does Apache County Allow ADUs?
Yes! Apache County must allow ADUs wherever single‑family residences are permitted under Arizona law, though there is no standalone ADU ordinance, leaving specific requirements up to local municipalities. However, ADUs would most likely fall under general accessory building rules, meaning they must adhere to setbacks of at least ten feet on all sides for single‑story structures, maintain separation between buildings (fifteen feet minimum for single‑story, twenty feet for multi‑story), and they must meet parking requirements similar to principal dwellings. You are not allowed to subdivide an ADU separately from the main dwelling and no other specific requirements are in place for ADUs, so it is important to reach out to your local municipality for the specific details. You can also contact the Apache Community Development Office for any further questions.
Does Cochise County Allow ADUs?
It sure does! Cochise County’s Accessory Living Quarters regulations require a planning review approval and owner occupancy in either the primary dwelling or the ADU. Within permitted rural and residential zoning districts ADUs must not exceed fifty percent of the livable square footage of the primary dwelling or 1,000 square feet, whichever is less, and must be equal to or lower in height than the main home.
An ADU without owner occupancy is not permitted and you need to request a special use permit if you are interested in renting out the ADU long-term. Additionally, you can not sell the two dwelling units separately within one year. Cochise County also requires all tiny homes follow IRC Appendix Q with a minimum of 296 square feet and 6′4″ ceiling and all other development standards like lot size and setbacks to match those of the main house.
If you are ready to start your ADU journey in Cochise County, request a free quote from Zook Cabins and we will be thrilled to assist you!
Does Gila County Allow ADUs?
Yes, Gila County has an ADU zoning ordinance for single family residential districts that allows one accessory dwelling unit by right, whether attached, detached or interior, on lots of at least 5,000 square feet. The ADU may not exceed the floor area of the primary residence and detached units must be separated from the main dwelling by at least ten feet; entrances are limited to one per side facing the street per story.
The property owner must reside in either the main dwelling or the ADU. One parking space is required per studio or one-bedroom unit and two for two-bedroom units, waste disposal facilities must be adequate, and design must visually match the primary structure. Conditional use permits can modify these conditions if requirements are met. Contact the Gila County Zoning Department for more info.
Does Graham County Allow ADUs?
As of now, there is no dedicated ADU ordinance publicly available for Graham County. However, under Arizona’s statewide law, ADUs must be permitted on land where single‑family homes are allowed. In the absence of specific rules for Graham County, homeowners should assume ADUs will fall under general accessory building requirements with all the required setbacks, height and lot‑coverage limits tied to those of the primary residence, and compliance with IRC Appendix Q if tiny‑home structures are used. For additional information, reach out to Graham County Zoning Department as they can provide specific guidance on how to proceed.
Does Greenlee County Allow ADUs?
Right now, Greenlee County must comply with Arizona’s statute allowing ADUs but has not published ADU-specific zoning rules. Therefore accessory dwellings are permitted in single‑family zones, subject only to accessory structure regulations which have guidelines on minimum setbacks, height limited to primary structure and lot‑coverage limits. No additional local ADU restrictions such as owner‑occupancy requirements, separate utility bans, parking mandates, or lease restrictions beyond state law are stated in the Greenlee County zoning ordinances.
If you are ready to start your ADU journey in Greenlee County, request a free quote from Zook Cabins and we will be thrilled to assist you!
Does La Paz County Allow ADUs?
La Paz County similarly must permit ADUs where single‑family homes are allowed but has no formal ADU ordinance. This lack of specific guidelines mean ADUs are treated as accessory buildings under general zoning. They must follow the state-wide setback requirements, height and lot-coverage rules that apply to other accessory structures. ADUs in La Paz County will also require permits and inspections. For specific details on the process, call the La Paz Planning and Zoning Department.
Does Maricopa County Allow ADUs?
Yes! Maricopa County conforms to state law by allowing at least one attached and one detached ADU per single‑family lot. ADUs cannot exceed 75% of the gross floor area of the primary dwelling or 1,000 square feet on parcels up to 10,000 square feet.
Setbacks for Maricopa County follow the zoning district standards but may be reduced to a minimum of five feet side and rear and detached ADUs cannot be in front of the primary dwelling. If the ADU is over 800 square feet, homeowners may face some impact fees. In Maricopa County, utilities may be separately metered dependent on the provider and driveway access must be shared with the primary dwelling. Maricopa County Zoning and Planning can provide the most specific and accurate ADU regulations.
If you are ready to start your ADU journey in Maricopa County, request a free quote from Zook Cabins and we will be thrilled to assist you!
Does Mohave County Allow ADUs?
Mohave County must allow ADUs per state law but does not have a specific ADU ordinance publicly available. ADUs would default to accessory structure zoning with required setbacks, height and lot‑coverage consistent with the main dwelling. Tiny homes must comply with IRC Appendix Q (400 square feet with 6′4″ ceiling, permit and inspection required). Any other questions about requirements regarding size restrictions, parking, and utility permits would have to be asked to the Mohave County Planning and Zoning Department.
Does Navajo County Allow ADUs?
While Navajo County has no county-specific ADU regulations anywhere online, state law mandates that municipalities within Navajo County with 75,000 or more residents must allow at least 1 detached and attached ADU per single-family lot. If the ADU is a tiny home, it will fall under the government of IRC Appendix Q standards with required permitting. There are no additional county restrictions on kitchens, separate utility meters, parking, owner occupancy, or rental duration beyond what state law prescribes. The Navajo County Planning and Zoning Commission can offer more specific assistance regarding ADU regulations.
Ready to invest in an ADU in Navajo County? Contact us at Zook Cabins or get a free quote to start the process!
Does Pima County Allow ADUs?
Yes! Pima County must allow ADUs and has a guest house/casita provision for parcels of at least 4,000 square feet in unincorporated areas. One detached guest house per lot is allowed if it meets zoning setbacks of 3 feet minimum separation from the main house. Pima County also requires that the ADUs use the same utilities and driveway as the primary dwelling.
Kitchens are allowed and long‑term rentals are permitted. There are no published zoning codes on size percentage, height relative to the main house, parking requirements, or owner‑occupancy requirements other than the state law standards. For specific county questions, reach out to the Pima County Zoning Department.
Does Pinal County Allow ADUs?
Pinal County has more contingencies on ADUs, based on their casita ordinance that allows exactly one guest house per lot where single‑family homes are permitted. The casita must not exceed 45 percent of the size of the main dwelling and cannot include a kitchen. It must also use the main building’s utilities, be located with setbacks matching the main house but no less than ten feet at the rear, and cannot exceed the height of the primary dwelling.
If you want to rent the ADU out, you can do so, but only long-term or if the short-term occupant is related to the homeowner. However, there is some relaxing of the ordinances around casitas in Pinal County and although nothing is finalized yet, it is important to keep in touch with the Pinal County Planning and Zoning Department for the most up-to-date information.
Does Santa Cruz County Allow ADUs?
Like a few other Arizona counties. Santa Cruz County must allow ADUs under state law but no dedicated ADU ordinance is publicly available; accessory dwellings are governed by general accessory structure zoning provisions, meaning setbacks, height and lot‑coverage must match those of the primary structure. Tiny-home units must comply with IRC Appendix Q (200‑400 square feet, 6′4″ minimum ceiling, permitting and inspection). Santa Cruz has a Planning and Zoning Commission that is a great place to find out more specific county information.
Ready to invest in an ADU in Santa Cruz? Contact us at Zook Cabins or get a free quote to start the process!
Does Yavapai County Allow ADUs?
Yavapai County must permit ADUs as required by state law but provides no separate ADU regulations. Therefore accessory units must meet the general accessory building standards in county zoning: setbacks, height and lot coverage tied to primary dwellings, building separation and coverage limits, and compliance with IRC Appendix Q rules where tiny homes are involved. Yavapai County Planning and Zoning is a good place to ask any further specific questions.
Does Yuma County Allow ADUs?
Although Yuma County is required to allow ADUs under state law, it does not have any county ADU‑specific regulations posted yet. This means that ADUs would fall under accessory structure zoning rules regarding height, setbacks and lot coverage. If built as tiny homes, they must follow IRC Appendix Q (200‑400 square feet, 6′4″ ceiling height, permit and inspection required). Beyond that, any requirements would simply fall under state standards. Yuma County Planning and Zoning can also provide more assistance.
Your Accessory Dwelling Units Requirements in Arizona By Municipality
| Phoenix | Phoenix Zoning Ordinances |
| Tucson | Planning and Zoning Applications |
| Mesa | Planning and Zoning Committee |
| Chandler | Planning and Zoning |
| Gilbert | Planning Commission |
Does Phoenix, Arizona, Allow ADUs?
Yes! Phoenix permits both attached and detached ADUs on any single‑family detached lot. Under Phoenix Zoning Ordinance Section 706, up to two ADUs (one attached and one detached) are allowed per property; a third detached unit is permitted on parcels of one acre or larger if at least one unit is designated as affordable housing.
If you have a detached ADU, it must meet all the required rear and side setbacks (minimum of five feet). Size is capped at 75% of the main house up to 1,000 sq ft for lots up to 10,000 sq ft or up to 3,000 sq ft (or 10% of lot area) for larger lots. Matching exterior design is encouraged if visible from the street but not legally mandatory. The homeowner is not required to have any additional parking spaces and can rent out the ADU for short-term rentals.
Ready to invest in an ADU in Phoenix? Contact us at Zook Cabins or get a free quote to start the process!
Does Tucson, Arizona, Allow ADUs?
It sure does! Tucson allows one ADU per residential lot, either detached, attached, or interior to the primary dwelling. ADUs are capped at 75% of the primary dwelling’s gross floor area, not exceeding 1,000 sq ft; every lot qualifies for a minimum ADU size of 650 sq ft. Detached units must maintain minimum setbacks of five feet from side and rear property lines. Maximum height is 12 feet or equal to the primary house height if it is two‑story.
There is no obligation to match exterior materials or roof pitch and short‑term rental rules follow state law without any added local restrictions beyond owner‑occupancy requirements for rentals. Tucson law regarding ADUs sunsets in five years and will be reviewed after one year in 2026, so contact the Tucson Planning and Zoning Department for the most up-to-date information.
Does Mesa, Arizona, Allow ADUs?
Yes, Mesa permits internal, attached, and detached ADUs by right in all single‑residence districts. One attached and one detached ADU are allowed per lot, regardless of zoning district, and a third detached ADU may be permitted on parcels of one acre or more if at least one ADU is deed‑restricted for affordable housing. New ADUs must observe five‑foot side and rear setbacks and ADU interior areas are capped at 75% of the primary home or 1,000 sq ft, whichever is less.
No additional parking is required for the ADU and if you are converting a garage or carport, garage replacement is not required. Utilities must be served by the same meters and providers as the main dwelling and you are only allowed to have one kitchen per ADU. The Mesa Zoning Department can help you on your ADU journey by answering any more questions.
Ready to invest in an ADU in Mesa? Contact us at Zook Cabins or get a free quote to start the process!
Does Chandler, Arizona, Allow ADUs?
Just like other major Arizona cities, Chandler must allow one attached and one detached ADU per single‑family lot under state law with the third permitted on lots over one acre. Chandler’s code limits ADU size to the lesser of 75% of the primary dwelling or 1,000 sq ft and applies standard five‑foot side and rear setbacks for detached units. Chandler allows kitchens in all ADUs and requires that ADUs are all built to building code standards. There are additional lot size and setback requirements, but it is essential to connect with the Chandler Zoning Department before proceeding any further.
Does Gilbert, Arizona, Allow ADUs?
Yes! Gilbert allows one attached and one detached ADU per single‑family residential lot under state law, and a third ADU may be added on lots over one acre with one unit designated as affordable housing. ADUs must remain on the same parcel, cannot be sold separately, and the primary residence must be owner‑occupied while the ADU can be rented out. Size is capped based on lot size and the primary dwelling footprint (typically up to 1,000 sq ft) and height must be consistent with the neighborhood character, though precise feet limits are not laid out in the summary.
Setbacks require placement behind the main dwelling and no less than approximately ten feet from property lines; design should match the main house in finish and roof pitch if visible from streetscape and vehicles must be parked behind the rear wall plane, screened from public view. Short‑term rentals are prohibited. For more information, you can contact the Gilbert Planning Commission for answers about permits, lot size, and other ADU requirements.
Searching For An ADU Builder Serving Arizona?
Now that you have learned all the exciting news about Arizona ADU regulations, it’s time to start investing into an actual ADU! We know it can be difficult to choose the best builder and provider when you have so many available options. That’s why Zook Cabins wants to offer you our guarantee of a job well done, with a quality and commitment you can trust. Using our years of experience and knowledge of the ADU world, we work with you to build you the ADU of your dreams.
Each of our modular ADUs are crafted with luxury yet functionality in mind. They are purposely designed with modern comfort in mind, and also efficiently constructed to maximize space.
Zook Cabins is excited to work with you in Arizona! Simply contact us today or request a free quote for your ideal ADU model.