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.
Broomfield’s real rules, taxes and rents — read from the codified ordinance, every figure sourced and dated. Here: a HUD benchmark rent of $1,754/mo for a 1-bed. Run your own numbers below, free.
Read from the Broomfield Municipal Code itself — the operative legal text, not a website summary. Broomfield 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 | Up to 500 sq ft in all cases; above that, the lesser of 800 sq ft or 50% of the main home's footprint (garage and porches excluded)verified October 2026Broomfield Municipal Code §17-32-160the ordinance textThe square footage of the accessory dwelling unit shall be no larger than 50% of the principal dwelling unit footprint or 800 square feet, whichever is less.; provided, that, in all cases, an accessory dwelling until may be up to 500 square feet in size regardless of the size of the principal dwelling unit. Square footage calculations, as contained herein, exclude any related garage, porch or similar area for the principal dwelling unit and accessory dwelling unit. |
| Owner occupancy | No — no owner-occupancy requirement, at application or afterwardsverified October 2026Broomfield Municipal Code §17-32-160the ordinance textSec. 17-32-160 (A)–(L), the full ADU section (amended through Ord. 2265, 2025), and the code's ADU and owner definitions contain no owner-occupancy or residency requirement. |
| Short-term rental | No — ADUs may not be used as short-term rentalsverified October 2026Broomfield Municipal Code §17-32-160the ordinance textAccessory dwelling units shall not be eligible for use as a short term rental, as defined in chapter 5-39 of the Broomfield Municipal Code. |
| Extra parking | None, unless all three apply: no existing off-street parking, no on-street parking on the adjacent streets, and the lot is outside a Parking Reduction Area — then 1 spaceverified October 2026Broomfield Municipal Code §17-32-040the ordinance textAccessory dwelling unit (ADU) No minimum parking is required with the following exceptions: 1 parking space is required if no existing off-street parking is available (driveway, garage, etc.), the adjacent streets do not allow on-street parking, and the ADU is not located in a Parking Reduction Area. |
| Water & sewer service | Must use the main home's water and sewer service — no separate services (phone, TV, electric and internet excepted); an ADU on septic needs a capacity review by Broomfield's public health departmentverified October 2026Broomfield Municipal Code §17-32-160the ordinance textWith the exception of telephone, television, electrical and internet service, accessory dwelling units must be served through the utility services of the principal dwelling unit and shall not have separate services. |
Source: Broomfield Municipal Code, §17-32-160 · ordinance text retrieved 2026-08-25, re-verified October 2026 · open “the ordinance text” under any figure to read the exact sentence it comes from.
Broomfield’s size cap is conditional rather than a single number: Up to 500 sq ft in all cases; above that, the lesser of 800 sq ft or 50% of the main home's footprint (garage and porches excluded) — worth reading closely before sizing a unit.
Short-term rental of the ADU is not permitted, so the model here is long-term tenancy or family use.
Parking: None, unless all three apply: no existing off-street parking, no on-street parking on the adjacent streets, and the lot is outside a Parking Reduction Area — then 1 space.
The federal benchmark for what an ADU rents for in Broomfield.
Rents: HUD Fair Market Rents, huduser.gov.
Two ways to build the same unit in Broomfield. 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 Broomfield’s size rule
≈ $2,800–$3,500 / month fully financed
In Broomfield, the 735 needs a main home with a footprint of at least 1,470 sq ft (garage and porches excluded)
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 Broomfield Municipal Code permits accessory dwelling units (§17-32-160), subject to the size, height, setback and use rules quoted above from the ordinance text. Broomfield 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 Broomfield 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 Broomfield Municipal Code: Up to 500 sq ft in all cases; above that, the lesser of 800 sq ft or 50% of the main home's footprint (garage and porches excluded). The Olerra Flex Flat 490 fits whatever the main home's size (any ADU up to 500 sq ft is allowed); the 735 needs a main home with a footprint of at least 1,470 sq ft (garage and porches excluded). The free property check confirms what fits on your lot.
No — ADUs may not be used as short-term rentals. Plan on long-term tenancy or family use.
Per the ordinance: No — no owner-occupancy requirement, at application or afterwards.
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.
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 — Broomfield, CO. Page updated October 9, 2026; rules verified October 2026. https://www.olerra.com/adu-calculator/broomfield/ <a href="https://www.olerra.com/adu-calculator/broomfield/">Broomfield 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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