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Longmont Zoning & Land Use Guide

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Key Zoning Facts

Planning Department
City of Longmont Planning & Development Services(303) 651-8330
Building Code Edition
2021 IBC with Longmont Amendments
ADUs Allowed
Yes
Primary District
R-SF Residential Single-Family
Max Height
35 ft

Longmont Zoning Overview

Longmont is a city of approximately 99,000 residents located in Boulder and Weld counties along the northern Front Range. The city has a diverse economy including technology, manufacturing, and aerospace, anchored by its growing downtown and Main Street corridor. Longmont's zoning code establishes residential, commercial, industrial, and mixed-use districts. The city's land use pattern includes a traditional grid-pattern downtown, established residential neighborhoods, and newer development on the city's edges. Longmont is notable for its municipal fiber-optic broadband network (NextLight), which has attracted technology companies and remote workers.

Longmont's Envision Longmont comprehensive plan guides future development with emphasis on a balanced transportation system, diverse housing options, and economic vitality. The city has been proactive in planning for housing affordability, including updating zoning regulations to accommodate a wider range of housing types. Longmont's recovery from the 2013 floods along the St. Vrain Creek involved significant floodplain management updates and resilient development standards.

Planning & Development Services manages zoning administration and building permits for the city.

Key Zoning Districts

Longmont's zoning includes R-SF (Single-Family), R-MF (Multi-Family), and Mixed Residential districts, along with Neighborhood Commercial (NC), Community Commercial (CC), and Regional Commercial (RC) districts. The city also uses Planned Unit Development districts for larger developments.

ADU Regulations

Longmont allows ADUs in residential zones under Colorado HB 24-1152. ADUs are limited to 800 square feet and 20 feet in height. No additional parking is required. Permits are processed within four to six weeks.

Development Process

Longmont uses administrative review for by-right development and Planning and Zoning Commission hearings for rezonings and conditional uses. Building permits are processed by the Building Division, with typical residential review times of four to six weeks.

Regulatory Layers That Apply in Longmont

Your property is subject to ALL of these regulatory layers. Each one can impose additional requirements beyond the others.

Federal

State — Colorado

  • Building Code: 2021 IBC (locally adopted)
View Colorado zoning overview

County — Boulder County

  • Role: Property records, tax assessment, unincorporated area planning

City / Municipal

The city's zoning ordinance, building codes, and local permits form the primary layer of land-use regulation for your property.

Overlay Districts

No overlay districts identified.

Private Restrictions

  • HOA / CC&Rs common: Yes
  • Check HOA CC&Rs for additional restrictions.

Primary Zoning Districts

R-SFResidential Single-Family
Min Lot
6,000 sq ft
Max Height
35 ft
Front Setback
20 ft
Side Setback
5 ft
Rear Setback
15 ft
R-MFResidential Multi-Family
Min Lot
6,000 sq ft
Max Height
45 ft
Front Setback
20 ft
Side Setback
10 ft
Rear Setback
15 ft
CCCommunity Commercial
Min Lot
None
Max Height
40 ft
Front Setback
10 ft
Side Setback
0 ft
Rear Setback
10 ft

ADU Rules in Longmont

ADUs:Allowed
Max Size
800 sq ft
Max Height
20 ft
Rear Setback
5 ft
Side Setback
5 ft
Parking
No additional parking required
Owner Occupancy
Not required
Permit Timeline
4-6 weeks

Permit Costs & Timelines

Permit Costs & Timelines

Specific permit fee schedules for Longmont are available from the local planning department. Fees vary based on project type, scope, and valuation.

Check Longmont permit fees →

Official Sources

Frequently Asked Questions

Can I build an ADU in Longmont?
Yes. Longmont allows ADUs on residential lots under Colorado HB 24-1152. A building permit is required.
How do I find the zoning for my property in Longmont?
Use the Longmont Planning & Development Services online zoning map, or call (303) 651-8330.
What zones allow multi-family housing in Longmont?
Multi-family housing is permitted in R-MF districts, Mixed Use zones, and certain Planned Unit Development areas.