Building a Casita in Maricopa County: 4 Things to Check

Under Arizona’s casita laws, most single-family lots in Maricopa County can have an ADU. But “most” isn’t “all.” Before you spend money on plans, check these four things. (New to the laws? Start with our breakdown of HB 2720 and HB 2928.)

First, confirm who your jurisdiction is

Your mailing address doesn’t decide which rules apply. Plenty of “Phoenix” or “Litchfield Park” addresses are actually unincorporated Maricopa County, and a city’s rules differ from the county’s. If you’re not sure, call Maricopa County Planning & Development at 602-506-3301 before you design anything.

1. Your HOA

State law doesn’t override your HOA’s CC&Rs. If your covenants prohibit detached structures, that restriction still applies. Read them first.

2. Utility easements

An ADU can’t be built on top of a public utility easement without written consent from the utility that uses it. Your plat or title paperwork will show whether you have one.

3. Proximity to airports and military facilities

The county requirements don’t apply to lots near a military airport, an FAA-licensed commercial or general aviation airport, or a public airport with noise above 65 decibels. That doesn’t automatically mean a casita is banned there. It means the county isn’t required to approve one, so confirm before you assume.

4. Tribal land

The county requirements also don’t apply to lots on tribal land.

Not sure where your lot stands?

Our free site evaluation covers these checks before you spend anything on design. See what a casita costs to build in Maricopa County, browse our casita designs, or contact us.

Frequently asked questions

Does my mailing address decide whether city or county rules apply?

No. Your parcel’s location decides. Many addresses with a city name are in unincorporated Maricopa County. Confirm with County Planning & Development at 602-506-3301.

Can I build a casita near an airport in Maricopa County?

Possibly. The state requirement doesn’t cover lots near certain airports and military facilities, so the county isn’t required to approve one there. It isn’t automatically banned, so confirm with the county first.