ADU construction

Phoenix's updated building construction code aligns with the city's broader commitment to sustainable growth in a desert environment. For backyard casitas and detached guest houses, this means new expectations around plumbing fixtures, water efficiency, and how interior square footage is planned and utilized. Key among these updates is alignment with EPA WaterSense standards for plumbing fixtures.

The City of Phoenix adopted the Phoenix Building Construction Code which includes an electric vehicle readiness requirement, the addition of EV charging infrastructure, on new builds in Phoenix to make it easier and more affordable to charge electric vehicles at home. In practical terms, this means new construction could include the conduit pathways and electrical panel capacity to support a future EV charging station — even if no charger is installed on day one.

AzADU casitas aren't modular boxes dropped in a backyard. They're stick-framed on a permanent slab-on-grade concrete foundation, built to the same structural standard as a primary residence. Dimensional architectural shingles with UV-resistant properties cap the roof, while gutters manage Arizona's intense monsoon runoff. Every unit is a real investment and it's protected like one.

For a detached casita or guest house, ARC review is typically mandatory before you break ground. Skipping this step can result in stop-work orders, fines, or costly modifications after construction is already underway. The good news: a well-prepared submission packet significantly accelerates the review and reduces the likelihood of back-and-forth requests for more information.

The magic of a detached structure is the psychological and acoustic separation it creates. When you walk across your backyard and step through that door, you're leaving the noise of the household behind. That mental shift is real, and it makes every session more intentional.

Most Phoenix homeowners assume building a backyard casita means years of waiting, stacks of paperwork, and an endless loop of city back-and-forth. The reality — when you have the right partner and the right plan — is a structured, eight-month journey from first site visit to handing over the keys. Here's exactly how AzADU makes that timeline achievable.

A home addition locks in its purpose. A casita adapts. Today it houses an aging parent. In three years, it becomes a home office. After that, it generates rental income while you travel. This lifecycle flexibility is one of a casita's most underrated financial advantages — the structure serves whatever your household needs at any given moment.