If you’ve been dreaming about adding an accessory dwelling unit (ADU) to your Phoenix property—whether as a rental, a guest house, or a cozy spot for family—you’re not alone. ADUs are gaining popularity as a smart, flexible housing solution in the Valley of the Sun. But before you break ground, there’s a lot to consider, from zoning laws to permitting processes.
The good news? We’re here to break it all down for you in a way that makes sense..
As a team of expert ADU builders in Phoenix, our team at DwellWell Tiny Homes is ready to help homeowners navigate the process. We’re uniquely familiar with the ins and outs of what it takes to build an ADU that meets city regulations while adding value to your property. Let’s dive into what you need to know before getting started!
What Is an Accessory Dwelling Unit (ADU)?
An accessory dwelling unit (ADU) is a self-contained living space located on the same lot as a primary residence. Also known as casitas, granny flats, or guest houses, ADUs can be attached to the main home or completely detached. These units typically include a kitchen, bathroom, and sleeping area, making them ideal for multi-generational living, rental income, or even a private workspace.
Are ADUs Allowed in Phoenix, Arizona?
Yes! The City of Phoenix has embraced ADUs as a way to provide more housing options. However, there are specific rules about where and how they can be built, so understanding zoning, permitting, and design regulations is essential.
What to Know About ADUs in Phoenix
Before building an ADU in Phoenix, it’s essential to understand the city’s regulations and requirements. This section covers the current ADU laws, the permitting process, zoning ordinances, and development standards to ensure your project meets all legal requirements. Knowing these details upfront will help you avoid costly mistakes and streamline the approval process.
Current Regulations
Phoenix allows up to two ADUs per single-family lot, with a third ADU permitted under certain circumstances. The size of the ADU depends on the lot size and primary dwelling:
- Each ADU may be up to 75% of the gross floor area of the main house.
- For lots under 10,000 sq. ft., ADUs can be up to 1,000 sq. ft.
- For lots over 10,000 sq. ft., ADUs can be up to 3,000 sq. ft.
- ADUs must comply with lot coverage guidelines and setback regulations.
Additionally, ADUs are allowed as long as the primary residence is a single-family detached home. Properties with duplexes or triplexes are not eligible for ADUs.
Permitting Process
To legally build an ADU in Phoenix, you’ll need a building permit. The process includes:
- Creating a site plan that meets city guidelines.
- Submitting your plans to the city for review.
- Obtaining necessary approvals and permits.
- Passing inspections throughout construction.
- Receiving a final Certificate of Occupancy.
You’ll also need to determine your lot size, setbacks, and zoning before submitting your application. Your ADU builder can handle the permitting process, or you can do your own research about your property using the City of Phoenix’s My Community Map tool.
Zoning Ordinances & Residential Districts
Phoenix zoning laws determine where ADUs are allowed. In most single-family residential zones (such as R1-6 and R1-10), ADUs are permitted. However, it’s crucial to check your specific zoning using My Community Map to ensure compliance.
Planning & Development Standards
Phoenix has specific development standards, including:
- Setbacks: ADUs must be built a certain distance from property lines.
- Height Restrictions: Usually lower than the main house.
- Parking Requirements: Some lots may require an additional parking space for the ADU.
- Design Compatibility: The ADU should complement the main home in terms of materials and aesthetics.
All of these factors may affect the viability of an ADU in your backyard. You’ll want to get in touch with an ADU expert who can help determine if your home can accommodate one of these wonderful tiny homes.
Advantages of Building an ADU in Phoenix
Building an ADU offers multiple benefits. For homeowners looking to generate extra income, an ADU can serve as a rental unit, providing a steady stream of passive revenue. Many property owners use ADUs to house aging parents or adult children, creating a multi-generational living solution while maintaining privacy for everyone involved. Others transform their ADUs into home offices, guest houses, or short-term rentals, maximizing their property’s flexibility.
For example, a homeowner in central Phoenix might build an ADU to rent out on a long-term lease, offsetting their mortgage. Another homeowner in the suburbs could construct an ADU to provide an independent living space for elderly parents who want to stay close but maintain their autonomy. The possibilities are vast, and each use case brings unique advantages tailored to individual needs.
How to Build an ADU in Phoenix
Before beginning your ADU project, the first step is to find a trusted ADU builder. A professional builder will help you navigate zoning laws, create a custom design, obtain necessary permits, and manage construction from start to finish. Working with an experienced team ensures your ADU complies with city regulations and is built efficiently and safely.
- Check Your Zoning: Confirm your property is eligible for an ADU. When you initially meet with your ADU builder, they should be able to navigate this process for you.
- Design Your ADU: Work with professionals (like us!) to create a functional, city-approved design. Often, ADU builders will have available models with completed floor plans for you to choose from.
- Obtain Permits: Once you’ve finalized your backyard cottage’s design, it’s time to submit plans to the city and get the necessary approvals.
- Begin Construction: Finally, it’s time to break ground. With your construction team and ADU builder, your ADU will be built according to approved plans. Required inspections will occur during this step of the process.
- Finalize with the City: Now that your ADU is complete, you’ll be able to acquire your Certificate of Occupancy to start using your ADU.
Get Started With DwellWell Tiny Homes
Building an ADU in Phoenix doesn’t have to be overwhelming. With the right team on your side, you can create a high-quality, compliant ADU that enhances your lifestyle and property value. If you’re ready to explore your options, get in touch with us today—we’ll handle the details so you can focus on enjoying your new space!
