What HB2720 Means for Your ADU Plans in 2026
HB2720 is Arizona's new statewide law focused on making it easier to build accessory dwelling units, or ADUs, on single-family lots. If you are thinking about a casita, guest house, or garage conversion in Phoenix, Mesa, or Queen Creek, this bill shapes what your city can and cannot say no to starting in the next couple of years.
We will walk through what changes under this new law, what still stays under local control, and how it ties into common goals like rental income, space for family, or boosting resale value. By the end, you should have a clearer idea of how HB2720 connects to your lot, your city, and your budget plans for an ADU project.
HB2720 Basics Every Arizona Homeowner Should Know
At a simple level, HB2720 is the state saying: single-family lots should be allowed to have at least one ADU, and cities cannot make it impossible through zoning rules. The bill pushes cities to let homeowners add a small second unit, either detached like a casita or attached like a converted garage or interior suite.
Key ideas behind the bill include things like:
- Allowing at least one ADU on most single-family lots
- Limiting cities from using lot size rules to block ADUs
- Trying to keep parking and design demands from getting out of hand
- Encouraging more housing choices on existing properties
The main rules roll out over time. Cities get a window to update their zoning codes to match the state standards. If you are planning a project that starts late in the year after the law takes hold, you will want to know which rules in your city are old and which are updated.
State law sets the floor. That means cities like Phoenix, Mesa, and Queen Creek can be more flexible, but they cannot be stricter than HB2720 on specific items covered by the bill. Local rules still matter, especially for things like where on the lot the ADU can sit and how big it can be.
How HB2720 Changes ADU Rules in Phoenix, Mesa, and Queen Creek
Phoenix already allows different types of ADUs in many zones, but homeowners run into the same kind of hurdles again and again. These often include tight setbacks, height limits, extra parking requirements, or rules about the owner having to live on the property.
Under HB2720, Phoenix will need to bring certain standards in line with state rules. In practice, this can mean:
- Less focus on minimum lot size as a reason to deny an ADU
- More room for one ADU per lot, even where rules were fuzzy before
- Fewer costly design add-ons that do not affect safety
- More predictable parking expectations
For many Phoenix homeowners, this opens the door to:
- Detached casitas in the backyard
- Garage conversions turned into legal guest suites
- Bringing older unpermitted structures up to code
In Mesa, ADUs are especially interesting in areas with larger lots, older subdivisions, and spots near transit or colleges, where long-term rentals are popular. HB2720 leans in the same direction, pushing the city to treat ADUs as allowed housing instead of special exceptions.
That can help Mesa homeowners who want:
- A rental unit to offset their mortgage
- A private space for parents or adult children
- Smaller, flexible housing on big lots that feel underused
Queen Creek has a different mix. There are semi-rural properties, many new-build neighborhoods, and a lot of HOAs. HB2720 speaks to city zoning rules, not private HOA documents. That means:
- The city may need to open the door more for ADUs on non-HOA lots
- On HOA lots, private CC&Rs can still limit or block ADUs
- The state law does not wipe out HOA rules
Across all three cities, some things do not change at all:
- You still need permits for any ADU
- You still go through inspections for safety and building codes
- Fire, electrical, plumbing, and structural rules still apply
So statewide approval does not mean you can build anything, anywhere. It means more lots are allowed to have one ADU, with fewer zoning roadblocks, as long as the project is properly planned and permitted.
Costs, Timelines, ROI, and Common Pitfalls Under the New Rules
Right now in the Phoenix metro, we see a wide range of project types, from small garage conversions to full detached casitas with kitchens and baths. HB2720 may not change the construction work itself, but it can affect soft costs like:
- Fewer redesigns to meet hard-to-predict local rules
- Less time spent on back-and-forth zoning questions
- More clarity up front on what will be approved
Permitting timelines can still stretch. As more homeowners hear about the new ADU rules in Arizona, cities may see a wave of applications. That can lead to longer review times if departments get backed up.
Many homeowners choose to:
- Start design and site planning before they are ready to build
- Lock in key layout and scope while rules are becoming clearer
- Use that time to line up financing and rental plans
On ROI, an ADU can support:
- Long-term rental income
- Space for family that avoids paying for off-site housing
- Added appeal when selling to buyers who want flexibility
Appraisers and buyers usually look at livable square footage, the quality of the build, and how well the ADU fits the lot. A well-planned unit that feels like part of the property, not an afterthought, tends to help both rental potential and resale value.
There are also pitfalls we see often:
- Old unpermitted work that must be corrected before new plans move forward
- Wrong guesses about setbacks or height that trigger redesigns
- DIY floor plans that need extra engineering or full redraws to pass review
Working with a single team that handles design, permits, and construction under one contract can keep those surprises from blowing up the budget.
Seasonal Timing Tips and FAQs for ADU Laws in Arizona After HB2720
Late summer is a smart time to think about an ADU build for the coming winter and spring. In the Phoenix area, those months are popular for construction because days are a bit easier on crews and materials. With HB2720 in play, contractor schedules may tighten as more owners and investors move ahead on postponed projects.
A simple timeline many homeowners like is:
- End of summer: site walk and early design decisions
- Early fall: zoning checks, detailed plans, and permit submission
- Late fall or winter: permit approval and construction start, depending on review times
Here are some quick FAQs we hear around ADU laws in Arizona after HB2720:
- Can my city still say no to ADUs on my lot under HB2720?
Cities generally must allow at least one ADU on qualifying single-family lots, but they can still limit placement, size, and height for safety and neighborhood fit. Some lots with special conditions or overlays may have tighter rules.
- Does HB2720 override my HOA's rules?
No. The law speaks to city and town zoning, not private CC&Rs. If your HOA restricts ADUs, you may need to work within those private rules or talk with the HOA about any changes.
- Will my property taxes go up if I build an ADU?
County assessors usually look at added livable square footage when they update your assessed value. That can raise your tax bill, but the added income or value from the ADU often helps offset that change over time.
- Can I use an ADU for short-term rentals like Airbnb?
HB2720 is about allowing ADUs. Short-term rental rules sit in a different set of city codes. If you plan to do short-term stays, you still need to follow your city's specific short-term rental regulations.
- Do I still need a permit for a garage conversion or interior ADU?
Yes. Any habitable space must meet building and safety codes, including structure, electrical, plumbing, and fire protection. HB2720 reduces some zoning barriers but does not remove permit requirements for ADUs of any kind.
Get Started With Your Project Today
If you are thinking about adding an accessory dwelling unit, we can help you navigate the specific ADU laws in Arizona and how they apply to your property. At Prime Builders, we review your goals, zoning, and budget so your project starts on a solid foundation. Reach out today so we can walk you through your options and outline a clear plan for permitting and construction.