Arapahoe County, CO Building Setbacks & Zoning: Setback Rules (2026)
Key Facts
- A-E/A-1 front setback
- 100 feet
- RR-A/RR-B/RR-C front setback
- 50 feet
- R-1-A/R-1-B front setback
- 25 feet
- Cluster lot reduction
- down to 75% of standard setback (note 10)
- Governing table
- LDC Table 4-1.1
- Applies only in
- unincorporated Arapahoe County
Summary
Unincorporated Arapahoe County sets minimum yard setbacks by zoning district in Table 4-1.1 of the Land Development Code. Agricultural districts A-E and A-1 require a 100-foot front setback; Rural Residential RR-A, RR-B and RR-C require 50 feet; the R-1-A and R-1-B residential districts drop to 25 feet. Side and rear minimums shrink the same way moving from agricultural toward higher-density residential zones.
A-E A-1 RR-A RR-B RR-C R-1-A R-1-B R-1-C R-1-D R-2-A R-2-B R-M R-MF
Setbacks, Principal Structure or Use (Minimum) (feet) Front 100 100 50 50 50 25 25 20[6], [10] 20[6], [10] 20[6] Living 20 Side, each 100 50 25 25 25 25 15 10[10] 5[10] 0 Rear 100 50 50 25 25 25 25 20[10] 15[10] 15 10 10
Full Breakdown
1, Agricultural and Residential District Dimensional Standards, in Chapter 4 of the Arapahoe County Land Development Code sets the front, side and rear yard setbacks that apply to unincorporated land only, none of this governs a lot inside Aurora, Centennial, Littleton, Englewood or any other incorporated city in the county. The Agricultural districts, A-E and A-1, carry the largest minimum front setback in the table at 100 feet, matched by a 100-foot side setback on each side. Moving into the Rural Residential tier, RR-A, RR-B and RR-C drop the front setback to 50 feet with 25-foot side yards.
The R-1-A and R-1-B single-family residential districts cut the front setback again to 25 feet, with garage doors held to a footnoted 20-foot minimum under note [6] and living-area walls to 15 feet under the same note. Rear setbacks track the same downward slope: 100 feet in A-E, 50 feet in A-1 and RR-A, and 25 feet through RR-B, RR-C and the R-1 tier, falling to 20 and 15 feet in R-1-C and R-1-D under note [10], which lets clustered residential lots build to 75 percent of the standard district setback. 1 before applying for a building permit, since the applicable district, not a countywide default, controls the number.
Violations & Fines
Arapahoe County's Planning Division enforces setback compliance at building permit review under the Land Development Code; a foundation or structure that encroaches into a required setback can be red-tagged, held pending a survey correction, or ordered relocated before a certificate of occupancy issues. An encroachment discovered after construction can require a variance application to the Board of Adjustment or removal of the offending portion of the structure at the owner's expense.
Frequently Asked Questions
What is the minimum front setback in unincorporated Arapahoe County?
Does this setback table apply inside Aurora or Centennial?
Can setbacks be reduced for a cluster development?
Sources & Official References
Other rules in Arapahoe County
Compare Arapahoe County to another location·View the Colorado building setbacks & zoning overview
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