The plans we build
Some of our pre-designed plans, each shown in one of five architectural styles.
Longmont has one of the most permissive ADU programs in Colorado. Over 19,000 properties qualify. We know the rules, the zoning, and the approval process inside and out.
19,364
ADU-ready properties
Identified from Longmont parcel data
$1,800–$2,200
Estimated monthly rent
1-bedroom ADU, current Longmont market
500–800 SF
ADU size by right
Larger if it stays within 50% of your home's finished, above-ground floor area · LDC §15.02.080.E
Longmont permits ADUs in most residential zones. The main constraints are setbacks, lot coverage, the ADU size band, and the 75% cap on all accessory buildings together. Our ADU finder checks all of these against your actual parcel.
Key requirements
Eligible zoning districts
R-SFSingle FamilyMost residential lots qualifyR-RURural / UrbanADUs permitted with standard setbacksR-MNMulti-NeighborhoodADUs permittedR-MFMulti-FamilyADUs permittedMU-DMixed Use DowntownADUs permittedMU-NMixed Use NeighborhoodADUs permittedMU-EMixed Use EmploymentADUs permitted in residential portionsN-AGNon-Urban AgricultureADUs permittedNot sure what zone you're in? The property finder shows your zoning automatically.
Check my propertySome of our pre-designed plans, each shown in one of five architectural styles.
The Longmont property finder uses real parcel data from Boulder County GIS and Longmont's building footprint records. Enter your address and see your actual lot, setbacks, and ADU placement options in 30 seconds.
Real parcel lines from the county · No login required
Keep exploring
ADU rules by city
Cited, city-by-city ADU rules across the Front Range.
Questions answered
Allowed, how big, what it costs, how long — answered from the adopted codes.
How the finder works
What to type, what you get back, and what it deliberately will not tell you.
Rental income potential
Rent, resale value, and what a permitted second unit adds to your property.
ADUs for family
Aging parents, multigenerational living, childcare.
How to finance an ADU
HELOC, construction loans, and CHFA options.
Process & timeline
What to expect from contract to move-in.
Floor plans & pricing
Five plans, three finish grades, five architectural styles.
About Addwell
Who we are and how we build.
