ADU Impact Fees: Mesa vs Phoenix
How do adu impact fees rules compare between Mesa, AZ and Phoenix, AZ?
Mesa and Phoenix have similar restriction levels.
Mesa, AZ
Maricopa County
Mesa charges development impact fees under Arizona Revised Statutes Section 9-463.05 for water, wastewater, parks, and public safety. HB 2720 requires that ADU impact fees be proportional to the ADU's service demand, not the full single-family rate. Mesa Utilities capacity fees apply when a new water meter is installed for an ADU.
View full Mesa rules →Phoenix, AZ
Maricopa County
Phoenix charges modest development impact fees on ADUs under Arizona Revised Statutes Section 9-463.05. HB 2928 caps ADU impact fees in cities over 75,000 at 50 percent of single-family rates. Phoenix water and wastewater capacity charges apply where new meters are installed.
View full Phoenix rules →Key Facts Comparison
| Fact | Mesa | Phoenix |
|---|---|---|
| Fee Authority | ARS §9-463.05 | ARS §9-463.05 |
| HB 2720 | Proportional ADU fees required | - |
| Water Meter | Capacity fee if new meter | - |
| Permit Fee | $500-$2,000 typical | $500-$1,500 typical |
| ADU Cap | - | 50% of single-family rate |
| Typical Total | - | $4,000-$8,000 |
Highlighted rows indicate differences between cities.
Mesa FAQ
How much are impact fees for a Mesa ADU?
Mesa impact fees vary by area and ADU size. Under HB 2720, fees must be proportional to the ADU's service demand, not the full single-family rate. Request a fee estimate from Mesa Development Services before submitting permits.
Do I need a separate water meter for my Mesa ADU?
Not required. Sharing the primary dwelling's water meter avoids Mesa Utilities capacity fees. A separate meter is optional but triggers a new meter installation fee plus capacity charges. Most homeowners share the meter unless they plan to rent the ADU separately.
Phoenix FAQ
How much are ADU impact fees in Phoenix?
Total impact fees typically run $4,000-$8,000 for a residential ADU. Under HB 2928, Phoenix must charge ADUs at no more than 50 percent of single-family rates in each category (water, wastewater, parks, fire, police, library, streets).
Are Phoenix ADUs under 750 sq ft exempt from impact fees?
No automatic exemption like California. Arizona HB 2928 caps ADU fees at 50 percent of single-family rates but does not provide a size-based exemption. Phoenix charges proportional fees regardless of ADU size.
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