ADU Impact Fees: Surprise vs Tempe
How do adu impact fees rules compare between Surprise, AZ and Tempe, AZ?
Surprise and Tempe have similar restriction levels.
Surprise, AZ
Maricopa County
Under ARS § 9-463.05 and the ADU preemption at ARS § 9-461.18, Surprise cannot charge development impact fees on ADUs under 1,000 square feet, and fees on larger ADUs must be proportionate to the unit's actual demand on infrastructure. The Surprise Development Services Fee Schedule sets building permit and plan-check fees through the Community Development Department. Water and wastewater capacity fees apply only when a new tap is installed.
View full Surprise rules →Tempe, AZ
Maricopa County
Tempe does not impose a dedicated ADU impact fee. Standard building, plumbing, mechanical, and electrical permit fees through Tempe Community Development apply based on construction valuation. Water and sewer development fees apply only when a new utility connection is installed. Arizona HB 2720 (ARS 9-461.18) limits fees that would effectively prohibit ADU construction.
View full Tempe rules →Key Facts Comparison
| Fact | Surprise | Tempe |
|---|---|---|
| State Exemption | ADUs < 1,000 sq ft exempt (ARS § 9-461.18) | - |
| Impact Fee Authority | ARS § 9-463.05 | - |
| Permit Fee Range | ~$500–$2,000 typical | - |
| Water/Sewer SDF | Only on new tap | - |
| Fee Schedule | Surprise Development Services | - |
| Dedicated ADU Impact Fee | - | None |
| Fee Authority | - | ARS 9-463.05 |
| State Cap | - | ARS 9-461.18 limits punitive fees |
| Utility Fees | - | Only if new meter or connection |
| Permit Fee Basis | - | Construction valuation |
Highlighted rows indicate differences between cities.
Surprise FAQ
Are ADU impact fees waived in Surprise?
Yes for ADUs under 1,000 square feet. ARS § 9-461.18 prohibits Surprise from charging impact fees on small ADUs. Larger ADUs pay proportional fees based on the principal dwelling's square footage under ARS § 9-463.05.
What does an ADU permit cost in Surprise?
Building permit and plan-check fees typically total $500–$2,000 for a small ADU sharing the main house's utilities. New water/sewer tap System Development Fees add several thousand dollars. Check the Surprise Development Services Fee Schedule for current rates.
Tempe FAQ
How much are impact fees for a Tempe ADU?
Tempe does not charge a dedicated ADU impact fee. You pay standard building, plumbing, mechanical, and electrical permit fees based on construction valuation, plus water and sewer development fees only if a new meter or service is installed. Request a written fee estimate from Tempe Community Development before submittal.
Can Tempe charge me the full single-family impact fee for an ADU?
No. Under ARS 9-461.18 (HB 2720), fees that would effectively prohibit ADU construction are barred. Tempe applies its standard transportation, parks, and public safety impact fees to new principal-unit construction, not as a duplicate charge on accessory dwelling units sharing the existing lot.
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