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.
Silverton’s real rules, taxes and rents — read from the codified ordinance, every figure sourced and dated. Here: a HUD benchmark rent of $1,119/mo for a 1-bed. Run your own numbers below, free.
Read from the Silverton Municipal Code itself — the operative legal text, not a website summary.
| Maximum ADU size | 800 sq ft or 50% of the main home's gross floor area, whichever is greater (at least 300 sq ft)verified October 2026Silverton Municipal Code §15-3-60the ordinance text"Any accessory dwelling unit (ADU) shall: a. Have a minimum size of 300 square feet usable floor area, as defined by the currently adopted building codes; b. Not exceed 800 square feet of usable floor space, or 50 percent of the gross floor area of the principal dwelling, whichever is greater;" |
| Short-term rental | Conditional: only with an annual Town vacation rental permit, and only the main home or the ADU, not both; not allowed in the C-1 and P districts or avalanche red zones; R-1, R-2 and C-2 are capped at 8 eachverified October 2026Silverton Municipal Code §15-3-60the ordinance textSec. 15-3-60(d)(5)a: "If the owner obtains a valid approval for a vacation rental pursuant to Section 15-3-50 (b)(4), the principal dwelling or the ADU can be used as a vacation rental, but not both dwellings." Sec. 15-3-50(b)(4)b: "(i) Permit Required. Property owners are required to obtain a Vacation Rental Permit pursuant to Section 15-8-30 (o) to operate a vacation rental within the town. ... (iii) Caps by Zoning District. Vacation rentals within the R-1, R-2, and C-2 zones are capped at a maximum of eight vacation rentals in each of these three zoning districts. (iv) Prohibitions. Vacation rentals within the C-1 and P zoning districts, and in the red zone of avalanche hazard areas, are prohibited. No vacation rental applications will be accepted by the Town in any zoning district involving a structure that does not yet exist and/or has not yet received a Certificate of Occupancy. (v) Separation Distance. No vacation rental application for a structure in the R-1, R-2, or C-2 zoning districts will be approved if the proposed vacation rental is within a 100 foot radius ... of a currently permitted vacation rental". Sec. 15-8-30(o)(6): "Vacation Rental Permits are valid for the calendar year in which the permit is approved." |
Source: Silverton Municipal Code, §15-3-60 · 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.
Silverton’s size cap is conditional rather than a single number: 800 sq ft or 50% of the main home's gross floor area, whichever is greater (at least 300 sq ft) — worth reading closely before sizing a unit.
Short-term rental is conditional: only with an annual Town vacation rental permit, and only the main home or the ADU, not both; not allowed in the C-1 and P districts or avalanche red zones; R-1, R-2 and C-2 are capped at 8 each.
Property tax runs lighter than most of the state here: 45.762 mills total in the example tax area (San Juan County tax area 112), about 49% below the median of the Colorado tax areas we track (levies vary by parcel).
And Silverton is one of only 30 Colorado jurisdictions certified ADU Supportive, which makes residents eligible for CHFA’s state-backed ADU financing — an interest-rate buydown and credit enhancement offered through participating lenders. Most of the Front Range doesn’t have this lever.
What an ADU adds to the tax bill in Silverton, and the federal benchmark for what it rents for.
Levies: San Juan County Assessor — 2025 Abstract of Assessment, Mill Levies & Important Tax Information (prepared January 2026) — example: San Juan County tax area 112; levies differ between tax areas inside Silverton; 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 Silverton. 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
Fits Silverton’s size rule
≈ $2,800–$3,500 / month fully financed
Fits Silverton’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 Silverton Municipal Code permits accessory dwelling units (§15-3-60), subject to the size, height, setback and use rules quoted above from the ordinance text. 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 Silverton 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 Silverton Municipal Code: 800 sq ft or 50% of the main home's gross floor area, whichever is greater (at least 300 sq ft). Both Olerra Flex Flats — the 490 and the 735 — fit under this rule. The free property check confirms what fits on your lot.
It depends: Only with an annual Town vacation rental permit, and only the main home or the ADU, not both; not allowed in the C-1 and P districts or avalanche red zones; R-1, R-2 and C-2 are capped at 8 each.
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 $315 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.
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Planning departments and journalists are welcome to reference this data.
Olerra ADU Cost Calculator — Silverton, CO. Page updated October 9, 2026; rules verified October 2026. https://www.olerra.com/adu-calculator/silverton/ <a href="https://www.olerra.com/adu-calculator/silverton/">Silverton 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.
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