Adams County, CO Building Setbacks & Zoning: Lot Coverage Limits (2026)
Key Facts
- R-1-C accessory coverage
- 900 sq ft
- R-2 accessory coverage
- 450 sq ft per unit
- R-3 / R-4 accessory coverage
- 80 sq ft per unit
- Agricultural accessory cap
- 2x principal floor area
- Accessory before dwelling
- Not allowed
Summary
Instead of a flat percentage cap, Adams County limits accessory building coverage: 900 square feet in the R-1-C district (single-family), 450 square feet per unit in R-2, and 80 square feet per unit in R-3/R-4. Accessory buildings can't precede the main dwelling.
The maximum accessory building coverage in a Residential-1-C District shall be nine hundred (900) square feet. Accessory buildings shall not be constructed prior to the principal dwelling on a lot.
Full Breakdown
Adams County DSR Section 3-13 caps maximum accessory building coverage in the R-1-C District at 900 square feet, and requires the principal dwelling to be built first. R-2 (Section 3-14) allows 450 square feet per two-family unit (up to 900 for a single-family accessory building); R-3 and R-4 allow 80 square feet per dwelling unit; Mobile Home districts allow 600 square feet. In agricultural districts, an accessory building may not exceed twice the floor area of the principal structure (aircraft hangars excepted). The Mixed-Use District uses a minimum floor-area ratio (FAR) of 0.75 rather than a coverage cap.
Violations & Fines
Exceeding the accessory coverage cap or building an accessory structure before the principal dwelling is a zoning violation subject to a variance or correction order under CRS 30-28-124.
Frequently Asked Questions
Does Adams County have a percentage lot-coverage limit?
Can I build a shed before my house?
Sources & Official References
Other rules in Adams County
Compare Adams County to another location·View the Colorado building setbacks & zoning overview
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