Accessory Dwelling Units (ADUs)​

What is an Accessory Dwelling Unit (ADU)? 


​ADUs, often referred to as guest houses, casitas, or granny flats are separate, self-continued living areas that are either fully detached structures or attached to an existing home, with its own external entrance. 

An ADU usually contains all of the amenities to operate as a fully independent, operational dwelling, including a kitchen, bathroom, living area and sleeping quarters. 

New Rules​

​In September 2023, the Phoenix City Council approved new rules to allow one ADU in all single-family residential properties for which the yard size and other parcel characteristics make them permissible.  ​

Learn More​

Read the ADU Fact Sheet

Curious if your property is suitable for an ADU?

Check out the Frequently Asked Questions at the bottom of this page for basic, preliminary information.

Please consult with the Planning and Development Department before making any decisions to alter your property. ​​​​​

​​Contact Us

Have questions about ADUs? Send us an email!

PDD Ombudsman

Frequently Asked Questions ​

What if I live in an HOA community? 

Check your HOA rules about accessory structures. 

I don't know if my home is in the correct zoning district. 

New rules allow guest houses in all single-family residential districts: R1-6, R-1-10...etc.

Use My Community Map to find out the zoning district for your home. 

How do I know if my lot is large enough to fit an ADU?

Each zoning district has “lot coverage" guidelines that define how much of your property can be covered by buildings or structures. The new guest house rules expand by 10 percent the amount of your property that can be covered except in the RE-43, RE-24, RE-35 or R 1-14 zoning districts.

In My Community Map​, link to the Phoenix Zoning Ordinance to determine the lot coverage allowance for your home. 

Where can I find my lot size?

​​Find your property on the Maricopa County Assessor's Office website. It will list your official lot size as well as the dimensions of the structures on your property. You can use these two figures to make a rough calculation of your current lot coverage.