Building Setbacks & Zoning in Longmont, CO

Every city handles building setbacks & zoning a little differently. In Longmont, Colorado, there are 2 distinct rules that residents and property owners should be aware of. Some are stricter than what neighboring cities enforce, and others are more relaxed. Here is what you need to know.

Setback Rules

Longmont's Land Development Code sets minimum yard setbacks by zoning district in the master dimensional table at Municipal Code Section 15.03.070, Table 15.03.020(14), which controls whenever a district-specific table conflicts. In the R-SF single-family district a dwelling needs a 15-foot front setback, cut to 10 feet with alley garage access, a 5-foot side yard, and a 20-foot rear yard, or 6 feet where the lot backs an alley.

Key details: R-SF front setback: 15 feet, 10 feet with alley garage access. R-SF side yard: 5 feet minimum. R-SF rear yard: 20 feet, 6 feet abutting an alley. R-MH front setback: 10 feet. Eaves and cornices: may encroach 2 feet into setback.

Section 15.09.030 makes it unlawful to develop, use, or subdivide land out of compliance with the Land Development Code, and Section 15.09.040 treats each day a violation continues as a separate offense. Under Section 15.09.050 the city can deny building permits, revoke an existing permit, issue a stop-work order, or abate the violation as a public nuisance under Chapter 9.04 and lien the property for the cost. Violations are also criminal under the general penalty in Section 1.12.010: up to a $500.00 fine, up to 90 days in jail, or both.

Structure Height Limits

In Longmont's R-SF single-family district, Table 15.03.020(2) of the Land Development Code caps building height at 35 feet. Section 15.03.080.D measures that height from the average finished grade at the center of every wall to the top of the highest part of the building, and the same 35-foot cap applies lot by lot regardless of roof style.

Key details: Max height, R-SF district: 35 feet. Measured from: average finished grade to highest point. Governing table: Table 15.03.020(2). Admin modification cap for height: 25 percent (about 8.75 feet). Rooftop exceptions: chimneys/elevators up to 10 ft, parapets 5 ft.

Building above 35 feet without an approved modification is a violation of the development code under section 15.09.030, and section 15.09.040 makes each day the violation continues a separate offense. The director can withhold or revoke building permits and certificates of occupancy, issue a stop-work order, and seek an injunction or abatement under chapter 9.04 (section 15.09.050). Administrative civil penalties run through chapter 2.97: $100 for a first administrative order, $200 for a second within 12 months, and $500 for a third or later order within that same 12-month window, with each day of continued violation counted separately. Any violation is also a criminal offense under the general penalty in section 1.12.010, punishable by a fine up to $500.00 and up to 90 days in jail, or both.

The Bottom Line

Longmont's building setbacks & zoning rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Longmont is broadly strict or permissive.

Keep in mind that Longmont can amend these rules at any council meeting. For the most current version of any rule mentioned here, check the specific ordinance page, where we track updates as they happen.