Maui County, HI Accessory Structures: ADU Impact Fees (2026)
Key Facts
- ADU fee rate
- One-half of standard water system development fee
- Governing sections
- §§ 14.07.070, 14.07.080(A)
- If later subdivided
- Pay remaining half at subdivision
- Fee schedule set by
- Annual County budget ordinance (§ 14.07.030)
- Applies to
- New and existing accessory dwellings
Summary
An accessory dwelling on Maui pays only half the water system development fee that a standalone home owes. Maui County Code section 14.07.080(A) sets the accessory dwelling building permit fee at one-half of the full water system development fee for the meter size required, and section 14.07.070 applies the same half-rate to a new meter added later for an existing accessory dwelling.
Additional meter(s) for existing accessory dwellings may be requested at premises presently provided water service and, if granted, shall be subject to one half of the water system development fee set forth in the annual budget. ... A.Any applicant for a building permit for an accessory dwelling will pay one-half of the water system development fee for the size meter required to be installed. If the accessory dwelling is later subdivided from the premises, the applicant for subdivision will pay the balance of the water system development fee in effect at the time of subdivision upon proof of the initial one-half payment and, upon the director's request, will be required to relocate the meter.
Full Breakdown
07 to pay for the department's costs of new source, transmission, and storage capacity. Accessory dwellings get a specific discount from the standard fee. 080(A) states that any applicant for a building permit for an accessory dwelling will pay one-half of the water system development fee for the size meter required to be installed, rather than the full fee a principal dwelling's permit would trigger. 080(A) requires the applicant for the subdivision to pay the remaining balance of the WSDF in effect at the time of subdivision, crediting the initial half payment, and the director can also require the meter to be relocated at that point.
070 extends the same half-rate to an existing accessory dwelling that did not previously have its own meter: an additional meter requested for an existing accessory dwelling, if granted, is subject to one-half of the water system development fee set in the annual budget rather than the full rate. 030 and varies by meter size, so the accessory dwelling discount is calculated as half of whatever that year's scheduled fee is for the required meter.
Violations & Fines
Chapter 14.07 does not frame a missed or underpaid water system development fee as a criminal violation; instead, section 14.07.090(A) simply bars the director from approving water service until the WSDF, including the accessory dwelling's half-rate portion, is paid in full or offset by an approved credit. An accessory dwelling later subdivided without paying the deferred second half of the fee under section 14.07.080(A) can be denied further water service or meter relocation until the balance is settled.
Frequently Asked Questions
Do accessory dwellings pay the full water system development fee on Maui?
What happens if my accessory dwelling is later subdivided?
Can I get a discounted fee for an additional meter on an existing accessory dwelling?
Sources & Official References
Other rules in Maui County
Compare Maui County to another location·View the Hawaii accessory structures overview
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