ADU (Accessory Dwelling Unit) Permit in Mesa (2026)

Can I build an ADU on my Mesa property?

Yes. Arizona HB 2297 (effective September 2024) requires Mesa to allow ADUs on single-family lots and removed the owner-occupancy requirement. ADUs can be up to 50% of your primary dwelling or 1,200 sqft (whichever is less). No extra parking is required. The 5-foot maximum side/rear setback law applies. Mesa permit fees are generally moderate — contact Mesa Development Services at (480) 644-2365 or apply online at onlineservices.mesaaz.gov.

Does Salt River Project (SRP) or APS serve my Mesa property for solar?

Most of Mesa is served by Salt River Project (SRP) — a not-for-profit water and power company. Some areas of western Mesa near the Phoenix border may be served by APS. Check your electric bill or visit SRP.com to confirm your service territory. SRP's solar interconnection uses a different rate program (E-27 Customer Generation Plan) than APS NEM 3.0 — SRP uses time-of-use export pricing. Contact SRP Solar at (602) 236-8888 before installing solar to understand current net metering terms.

What are Mesa's Valley Metro Light Rail benefits for ADU development?

Mesa's Light Rail (Valley Metro Blue Line) runs along Main Street with stations at Sycamore, Country Club, Center, Mesa Drive, Gilbert Road, and Higley. Properties near these stations benefit from Mesa's Transit-Oriented Development (TOD) overlay zoning which allows higher density, reduced parking, and mixed-use development. ADU projects near light rail stations may qualify for reduced parking requirements. The light rail also makes ADU rental units near Main Street attractive to car-free tenants working in Phoenix or Tempe.

How do Mesa development fees affect ADU costs?

Mesa charges development fees for new dwelling units including ADUs. Key fees include: Water Capital Recovery Fee ($1,500–$3,000 depending on meter size), Wastewater Development Fee ($1,000–$2,500), and Transportation Development Fee (varies by location and unit type). Total development fees typically range from $3,000–$7,000 for a standard detached ADU. These fees are in addition to building permit fees. Contact Mesa Finance at (480) 644-2281 for current fee schedules before budgeting your ADU project.

How does Mesa compare to Phoenix for ADU rules?

Mesa and Phoenix both follow Arizona HB 2297 partial preemption with identical key provisions: no owner-occupancy requirement, 5-foot maximum rear/side setbacks, no extra parking. Phoenix limits ADU height to 24 feet single-story; Mesa also limits to 24 feet single-story. Both limit ADU size to 50% of primary dwelling or 1,200 sqft. The key operational differences are utilities (SRP vs APS), development fee schedules, and permit processing volumes (Phoenix processes significantly more permits with longer wait times). Mesa's fees are generally similar to Phoenix's.

Is Mesa's extreme heat a problem for ADU construction?

Yes — Mesa's summer temperatures regularly exceed 110°F in June-July, making proper insulation and HVAC critical for any ADU. Budget for high-performance construction: R-38+ ceiling insulation, R-13+ wall insulation, low-SHGC windows (<0.25), and a high-efficiency 18+ SEER central air conditioning system. A garage conversion ADU without these upgrades can be uncomfortably hot and have $250+ monthly cooling bills in summer. The investment in quality insulation typically pays back within 3-5 years through reduced energy costs.