Weld County, CO Accessory Structures: ADU Impact Fees (2026)
Key Facts
- Exemption scope
- Only accessory structures adding no dwelling unit
- ADU status
- Not exempt; owes road and facilities fees
- Fee due
- At or before building permit issuance
- Legal authority
- C.R.S. § 29-20-104.5
- Fee schedule
- Appendix 5-N, adjusted yearly for inflation
- Road fee districts
- Four benefit districts split by US-85/US-34
- Appeal window
- 10 days to Director, Land Use Type only
Summary
Weld County's Impact Fee Ordinance charges road, drainage and county-facilities impact fees on new development in the unincorporated area. Under Weld County Code § 20-1-70(A), an accessory structure is exempt from road and facilities fees only if it does not create an additional dwelling unit, so an Accessory Dwelling Unit owes the fee.
The following shall be exempt from the terms of this Chapter. An exemption must be claimed by the fee payer at the time of issuance of a building permit. The Director shall determine the validity of any claim for exemption.
A. Any residential remodeling, enlargement, addition, replacement or construction of accessory structures that does not result in the creation of any additional dwelling units, shall be exempt from road and County facilities impact fees, but not drainage impact fees.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Charter and County Code: Supplement 95).
Full Breakdown
Weld County adopted its Impact Fee Ordinance (Weld County Code Ch. 20, Art. 5, finding that new development in the unincorporated county must bear a proportionate share of the road, drainage and county-facilities capital costs it generates (§ 20-1-10). The fee applies countywide to unincorporated land, and collection occurs at or before issuance of a building permit, or at final development approval if no permit is required (§ 20-1-20(C), (D)). Section 20-1-70(A) carves out one narrow accessory-structure exemption: remodeling, enlargement, addition, replacement or construction of an accessory structure is exempt from the road and county-facilities fees, but only if it does not result in the creation of an additional dwelling unit, and drainage impact fees are never exempted.
Because an Accessory Dwelling Unit by definition adds a dwelling unit, it falls outside that exemption and is billed under the Department of Planning Services' fee schedule in Appendix 5-N, which the Board of County Commissioners adjusts each year for inflation using the Denver-Boulder-Greeley CPI (§ 20-1-60(B), (C)). S. S. Highway 34, and county-facilities and drainage fees each have one countywide benefit district, with funds restricted to capital improvements that expand capacity rather than routine maintenance (§ 20-1-100(A), (C)).
Violations & Fines
A building permit for a new ADU will not issue until the impact fee is paid or a credit/exemption is confirmed by the Department of Planning Services (§ 20-1-20(D), § 20-1-60(D)). A fee payer who disputes the Land Use Type applied to the ADU may file a written appeal with the Director within ten days of the written fee decision; the Director's ruling can then be appealed to the Board of County Commissioners under the Section 2-4-10 appeal procedure, after which the payer may still pursue an Independent Fee Analysis (§ 20-1-60(H), § 20-1-80).
Frequently Asked Questions
Does building a shed or detached garage trigger Weld County's impact fee?
Why isn't an Accessory Dwelling Unit covered by that exemption?
When does the ADU impact fee have to be paid?
Can I dispute the impact fee charged for my ADU?
Sources & Official References
Other rules in Weld County
Compare Weld County to another location·View the Colorado accessory structures overview
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