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.
Monument’s real rules, taxes and rents — read from the codified ordinance, every figure sourced and dated. Here: a HUD benchmark rent of $1,464/mo for a 1-bed. Run your own numbers below, free.
Read from the Monument Code Of Ordinances itself — the operative legal text, not a website summary. Monument 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 | The greater of 50% of the main home's floor area or 750 sq ft (the code's words say 750 but its numerals print 650; confirm with the Town). Large Lot Residential District: up to 1,250 sq ft.verified October 2026Monument Code Of Ordinances §18.03.340the ordinance textThe floor area of an ADU shall not exceed fifty (50) percent of the floor area of the principal structure or seven hundred fifty (650) square feet, whichever is greater. In the Large Lot Residential District the floor area of an ADU may be greater than seven hundred fifty (750) square feet, but shall not exceed one thousand two hundred fifty (1,250) square feet. |
| Minimum ADU size | 500 sq ftverified October 2026Monument Code Of Ordinances §18.03.340the ordinance textIn no case can an ADU be smaller than five hundred (500) square feet. |
| Height limit | Detached ADU: 16 ft, or up to 25 ft if created by converting an existing garage. Attached or integrated ADU: no more than the principal building's maximum permitted height in the zone, nor 25 ft.verified October 2026Monument Code Of Ordinances §18.03.340the ordinance textAttached or integrated ADUs shall not exceed the maximum permitted height of the principal building in the applicable zoning district, nor twenty-five (25) feet. Detached ADUs shall comply with the height restriction in the applicable zone district, except that no detached ADU shall exceed sixteen (16) feet in height, unless the detached ADU is created through the conversion of an existing garage, and does not exceed twenty-five (25) feet in height. |
| Owner occupancy | Yes, at application only: the owner must show they reside on the parcel when applying to build or convert an ADU. The code's wording on ADUs built together with a new home is unclear; confirm with the Town.verified October 2026Monument Code Of Ordinances §18.03.340the ordinance textOwner Occupancy Required. The property owner must demonstrate that the property owner resides on the parcel when an application is submitted: i. To construct or convert an accessory dwelling unit. This exception does not apply for an accessory dwelling unit that is being constructed simultaneously with a new primary dwelling unit. |
| Short-term rental | No - no ADU, or any dwelling unit on the same lot as an ADU, may be used for short-term rentals (rental for 30 days or less)verified October 2026Monument Code Of Ordinances §18.03.340the ordinance textShort-Term Rentals Prohibited. No ADU or any dwelling unit on the same lot as an ADU may be used for short-term rentals. For purposes of this provision, rental of any dwelling unit for thirty (30) days or less is a short-term rental. |
| Extra parking | 0 - additional parking is not required; exception: 1 off-street space is required only if the lot has no existing off-street parking space, the block prohibits on-street parking for any reason, and the zone requires one or more spaces for the principal dwellingverified October 2026Monument Code Of Ordinances §18.03.340the ordinance textParking. Additional parking is not required to be provided in conjunction with the construction or conversion of an ADU. i. Exception. One off-street parking space will be required if all of the following conditions apply: A. There is no existing off-street parking space on the lot; and B. The lot is located on a block where on-street parking is prohibited for any reason; and C. The lot is located in a zone district that requires one or more parking spaces for the principal dwelling. |
| Setbacks | Detached ADU: rear yard setback may follow the zone's accessory-structure setback. Attached or integrated ADU: only the ADU portion may use a reduced rear setback equal to the accessory-structure setback or 5 ft, whichever is greater. Other setbacks follow the zone district.verified October 2026Monument Code Of Ordinances §18.03.340the ordinance textRear yard setbacks for detached ADUs may follow the setback requirements established for accessory structures within the applicable zoning district. For attached or integrated ADUs, only the portion of the structure that contains the accessory dwelling unit may utilize a reduced rear yard setback equal to that required for accessory structures, or five (5) feet, whichever is greater. |
| Water & sewer service | Must connect to the Town's and/or district's central water and/or sewer systems (or a permitted well capable of serving an ADU); separate water and sewer taps are not permitted for ADUs, so the ADU shares the main home's serviceverified October 2026Monument Code Of Ordinances §18.03.340the ordinance textAn ADU must be connected to the Town's and/or a district's central water and/or sewer systems in conformance with the applicable utility regulations. An ADU may be served by a permitted well system capable of serving an ADU. Separate water and sewer taps shall not be permitted for ADUs. |
Source: Monument Code Of Ordinances, §18.03.340 · 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.
Monument’s size cap is conditional rather than a single number: The greater of 50% of the main home's floor area or 750 sq ft (the code's words say 750 but its numerals print 650; confirm with the Town). Large Lot Residential District: up to 1,250 sq ft. — worth reading closely before sizing a unit.
Owner occupancy: Yes, at application only: the owner must show they reside on the parcel when applying to build or convert an ADU. The code's wording on ADUs built together with a new home is unclear; confirm with the Town.
Short-term rental of the ADU is not permitted, so the model here is long-term tenancy or family use.
Parking: 0 - additional parking is not required; exception: 1 off-street space is required only if the lot has no existing off-street parking space, the block prohibits on-street parking for any reason, and the zone requires one or more spaces for the principal dwelling.
And Monument 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.
The federal benchmark for what an ADU rents for in Monument.
Rents: HUD Fair Market Rents, huduser.gov.
Two ways to build the same unit in Monument. 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 Monument, the 490 is below Monument's 500 sq ft minimum ADU size
≈ $2,800–$3,500 / month fully financed
In Monument, the 735 fits under the code's 750 sq ft figure; if the printed 650 applies instead, it needs a main home of at least 1,470 sq ft, so confirm with the Town
Olerra ranges: published all-in project pricing, September 2026 — site preparation, foundation, utility connections and permitting included.
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Yes. The Monument Code Of Ordinances permits accessory dwelling units (§18.03.340), subject to the size, height, setback and use rules quoted above from the ordinance text. Monument 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 Monument 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 Monument Code Of Ordinances: The greater of 50% of the main home's floor area or 750 sq ft (the code's words say 750 but its numerals print 650; confirm with the Town). Large Lot Residential District: up to 1,250 sq ft. The Olerra Flex Flat 490 is below Monument's 500 sq ft minimum ADU size; the 735 fits under the code's 750 sq ft figure; if the printed 650 applies instead, it needs a main home of at least 1,470 sq ft, so confirm with the Town. The free property check confirms what fits on your lot.
No - no ADU, or any dwelling unit on the same lot as an ADU, may be used for short-term rentals (rental for 30 days or less). Plan on long-term tenancy or family use.
Per the ordinance: Yes, at application only: the owner must show they reside on the parcel when applying to build or convert an ADU. The code's wording on ADUs built together with a new home is unclear; confirm with the Town.
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 — Monument, CO. Page updated October 9, 2026; rules verified October 2026. https://www.olerra.com/adu-calculator/monument/ <a href="https://www.olerra.com/adu-calculator/monument/">Monument ADU rules & costs</a> Page updated October 9, 2026. The oldest dated figure on the page is from October 8, 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 October 8, 2026, re-verified October 2026. Olerra pricing: published all-in project ranges, September 2026. Corrections: sales@olerra.com.
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