Setback Rules: Boulder vs Longmont
How do setback rules rules compare between Boulder, CO and Longmont, CO?
Boulder and Longmont have similar restriction levels.
Boulder, CO
Boulder County
Boulder zoning code requires minimum setback distances from property lines for all structures. Setbacks vary by zoning district and structure type.
View full Boulder rules →Longmont, CO
Boulder County
Longmont sets residential building setbacks by zoning district in the Land Development Code (LMC § 15.03.080). In R-SF: 15 ft front yard dwelling (10 ft with alley garage, 20 ft for front-facing garage), 5 ft side yard, 20 ft rear (6 ft if abutting an alley). Detached accessory structures must sit at least 5 feet from rear and side property lines and behind the front facade.
View full Longmont rules →Key Facts Comparison
| Fact | Boulder | Longmont |
|---|---|---|
| Front | 20 to 25 feet typical | - |
| Side | 5 to 10 feet typical | - |
| Rear | 15 to 20 feet typical | - |
| Variance | Zoning board hearing | - |
| Code Section | - | LMC § 15.03.080 (Dimensional Standards / Exceptions) |
| R-SF Front (dwelling) | - | 15 ft |
| R-SF Front (front-facing garage) | - | 20 ft |
| R-SF Side | - | 5 ft |
| R-SF Rear (no alley) | - | 20 ft |
| R-SF Rear (with alley) | - | 6 ft |
| R-RU Front / Side / Rear | - | 20 / 10 / 20 ft |
| Accessory Structures (rear/side) | - | 5 ft (behind front facade) |
Highlighted rows indicate differences between cities.
Boulder FAQ
How do I find my setback requirements?
Check Boulder zoning map for your parcel’s zoning district, then consult the zoning code for that district’s setbacks.
Can I build closer than the setback?
Only with a variance approved by the zoning board or if your structure qualifies for an exception.
Longmont FAQ
What are the residential setbacks in Longmont?
In the R-SF (Residential Single Family) zone — Longmont's most common residential district — the setbacks under LMC § 15.03.080 are 15 ft front yard for the dwelling (10 ft with alley garage access, 20 ft for a front-facing garage), 5 ft side yard, and 20 ft rear yard (6 ft if the lot abuts an alley). R-MN and R-MF use the same front/side numbers but have shorter rear setbacks (15 ft and 10 ft respectively); R-RU is 20/10/20.
How far does a detached garage or shed have to be from the property line in Longmont?
Detached accessory structures — sheds, detached garages, carports, ADUs — must be at least 5 feet from both rear and side property lines and must sit behind the front facade of the principal building, per the accessory structure standards in LMC § 15.03.080.C. The total combined floor area of all accessory structures on the lot may not exceed 75% of the principal structure.
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