How to Choose an ADU Contractor in Colorado (Questions to Ask)
How to hire an ADU contractor in Colorado, the questions to ask, the red flags to avoid, how licensing works here, and modular versus site-built compared.
Eaton’s real rules, taxes and rents — read from the codified ordinance, every figure sourced and dated. Here: a HUD benchmark rent of $1,238/mo for a 1-bed. Run your own numbers below, free.
Read from the Eaton Municipal Code itself — the operative legal text, not a website summary. Eaton is an HB24-1152 subject jurisdiction: since June 30, 2025, state law requires it to allow an ADU wherever it allows a single-family home, with administrative approval — the local standards below still apply.
| Maximum ADU size | 750 sq ft (lots ≤1.5 acres); 1,000 sq ft (lots >1.5 acres)verified September 2026Eaton Municipal Code §7-2-27.1the ordinance textIf the residential lot upon which the ADU will be constructed is less than or equal to 1.5 acres, the ADU shall be no greater than 750 square feet. If the residential lot upon which the ADU will be constructed is larger than 1.5 acres, the ADU shall be no greater than 1,000 square feet. |
| Size relative to the main house | 100%verified September 2026Eaton Municipal Code §7-2-27.1the ordinance textNotwithstanding the foregoing, in no case shall the ADU exceed the square footage of the primary dwelling unit. |
| Minimum ADU size | 500 sq ftverified October 2026Eaton Municipal Code §7-2-27.1the ordinance text(2) The ADU shall be no less than 500 square feet. |
| Owner occupancy | Owner-occupancy proof required only at time of building permit application; ordinance does not state an ongoing/continuing occupancy requirement thereafter.verified September 2026Eaton Municipal Code §7-2-27.1the ordinance textThe applicant shall provide proof of owner-residency when the building permit application is filed. |
| Extra parking | 0 (1 required only if there is no existing off-street parking and on-street parking is prohibited)verified September 2026Eaton Municipal Code §7-2-27.1the ordinance textIf there is no existing off-street parking and on-street parking is prohibited, one new parking space shall be required for the ADU. |
Source: Eaton Municipal Code, §7-2-27.1 · ordinance text retrieved 2026-10-08, re-verified October 2026 · open “the ordinance text” under any figure to read the exact sentence it comes from.
Eaton’s size cap is conditional rather than a single number: 750 sq ft (lots ≤1.5 acres); 1,000 sq ft (lots >1.5 acres) — worth reading closely before sizing a unit.
The cap is also relative: an ADU here may not exceed 100% of the main house, so a smaller primary home means a smaller buildable ADU.
Parking: 0 (1 required only if there is no existing off-street parking and on-street parking is prohibited).
Property tax runs lighter than most of the state here: 79.951 mills total in the example tax area (Weld County tax area 5059), about 11% below the median of the Colorado tax areas we track (levies vary by parcel).
What an ADU adds to the tax bill in Eaton, and the federal benchmark for what it rents for.
Levies: Weld County Assessor, 2025 Mill Levy Report (Tax District and Authority Report) — example: Weld County tax area 5059; levies differ between tax areas inside Eaton; check your parcel with the county assessor. Rates: Colorado DOLA, TY2026 — the 10% reduction on the first $700,000 of value applies to the local-government portion, once per property. Rents: HUD Fair Market Rents, huduser.gov.
Two ways to build the same unit in Eaton. Both figures are all-in — design, permits, foundation, utility connections and installation.
Published Front Range ranges for a comparable one-off build, 2025–26
≈ $2,100–$2,600 / month fully financed
In Eaton, the 490 is below Eaton's 500 sq ft minimum ADU size
≈ $2,800–$3,500 / month fully financed
Fits Eaton’s size rule
Olerra ranges: published all-in project pricing, September 2026 — site preparation, foundation, utility connections and permitting included.
Free and specific to you. Want to go further?
Yes. The Eaton Municipal Code permits accessory dwelling units (§7-2-27.1), subject to the size, height, setback and use rules quoted above from the ordinance text. Eaton is also an HB24-1152 subject jurisdiction, so since June 30, 2025 state law requires it to allow an ADU wherever it allows a single-family home, with administrative approval; the local standards above still apply. Zoning district, lot size and setbacks still decide what fits on a specific lot — the free property check confirms yours.
Yes. An ADU is a new dwelling unit, so Eaton requires a building permit (plus any zoning or site-plan review the code calls for) before construction starts. Olerra's all-in price includes permitting, and factory-built units are inspected to the same building code as a site-built home.
Per the Eaton Municipal Code: 750 sq ft (lots ≤1.5 acres); 1,000 sq ft (lots >1.5 acres). The Olerra Flex Flat 490 is below Eaton's 500 sq ft minimum ADU size; the 735 fits under this rule. The free property check confirms what fits on your lot.
Per the ordinance: Owner-occupancy proof required only at time of building permit application; ordinance does not state an ongoing/continuing occupancy requirement thereafter.
A one-off site build with a general contractor typically runs about $500,000–$650,000 for a ~490 sq ft unit. Olerra's factory-built Flex Flats run $300,000–$365,000 (490) and $420,000–$465,000 (735) all-in — site preparation, foundation, utility connections and permitting included.
Roughly $552 per year for every $100,000 of value the ADU adds, in the example tax area shown above: Colorado's TY2026 school (7.05%) and local-government (6.80%) assessment rates on the latest certified (TY2025) levy, a mixed-year estimate. Levies differ between tax areas, so check your parcel with the county assessor.
Same method, each city’s own ordinance. The Colorado hub lists every city, and the statewide ADU calculator covers any Colorado address.
Guides and real Colorado numbers from our team — a fresh pick every couple of weeks, or search for exactly what you need.
How to hire an ADU contractor in Colorado, the questions to ask, the red flags to avoid, how licensing works here, and modular versus site-built compared.
Latest articles
Planning departments and journalists are welcome to reference this data.
Olerra ADU Cost Calculator — Eaton, CO. Page updated October 9, 2026; rules verified October 2026. https://www.olerra.com/adu-calculator/eaton/ <a href="https://www.olerra.com/adu-calculator/eaton/">Eaton ADU rules & costs</a> Page updated October 9, 2026. The oldest dated figure on the page is from August 25, 2026.
Planning estimates, not quotes or legal advice. Rules, fees, levies and rents change — confirm with the city and your lender before committing. Rules data: codified ordinance as of August 25, 2026, re-verified October 2026. Olerra pricing: published all-in project ranges, September 2026. Corrections: sales@olerra.com.
Built for your location and what you want to do.
We'll be in touch before then — a confirmation is on its way to your email.
Thanks — we’ll reply to your email, usually the same day.
Our team is already on it — here’s what happens next.
