Colorado's HB24-1152 made accessory dwelling units allowed by right across most of the Front Range. We keep the actual rules — size, setbacks, parking, owner-occupancy — cited, city by city. Pick yours.
See if an ADU fits your lotBoulder County
Longmont
✓ Allowed by right
At least 800 sq ft — more on a larger house
Boulder County
Boulder
✓ Allowed by right
Up to 800 sq ft
Boulder County
Louisville
✓ Allowed by right
Up to 800 sq ft
Boulder County
Lafayette
✓ Allowed by right
Up to 750 sq ft
Boulder County
Superior
✓ Allowed by right
At least 750 sq ft — more on a larger house
Boulder & Weld Counties
Erie
✓ Allowed by right
No fixed size cap
City & County of Broomfield
Broomfield
✓ Allowed by right
Up to 800 sq ft
Weld County
Frederick
✓ Allowed by right
At least 800 sq ft — more on a larger house
Larimer & Weld Counties
Berthoud
✓ Allowed by right
Up to 850 sq ft
Unincorporated Boulder County
Boulder County
! Special review required
Up to 700 sq ft
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.