Building permits, zoning and septic rules in Larimer County, Colorado

Code-regulated construction needs a building permit before work begins in unincorporated Larimer County¹. Listed exceptions include certain decks, finish work, same-material repairs, concrete flatwork and accessory structures no larger than 200 square feet when they create no hazard; building and land-use requirements still apply¹. Larimer County enforces its 2024 building codes effective January 1, 2026, and the 2026 National Electrical Code effective August 1, 2026². Required inspections must be requested at the appropriate time¹¹. New residential and commercial structures receive a Certificate of Occupancy after final approval; cabins and accessory structures receive letters of completion¹². Inside Fort Collins, the city issues its own building permits, and Larimer County Health Department approval is still required for individual sewage disposal systems¹³. Inside Wellington, the town requires building permits for all sheds¹⁴. Estes Park handles covered construction under its own building-permit rules, with listed exemptions¹⁵. Berthoud, mainly in Weld County but extending into Larimer County, handles building permits for new homes and covered residential work¹⁶. Larimer County Health and Environment requires septic permits countywide⁴.

The Larimer County Building Division handles building permits, plan review, inspections and code enforcement throughout unincorporated Larimer County; its office is at 200 W. Oak Street, Suite 3100, and the main phone is (970) 498-7700². The property owner remains responsible for the building permit even when a contractor obtains it⁵. Residential and commercial applications must be submitted in hard copy; the online portal accepts miscellaneous, utility and solar building-permit applications⁵. Building permit and capital expansion fees changed July 1, 2026, with transportation capital expansion fees increasing October 1, 2026; building permit and impact fees depend on permit type, so use the current county fee schedules^2,17. A homeowner acting as general contractor for a new dwelling on the homeowner's property must use licensed subcontractors for work not performed personally and must not have built another Larimer County dwelling in the preceding 24 months¹⁸. The required Homeowner Certification and Responsibilities form is available through the building-permit application page⁵.

Larimer County zoning governs uses and development outside city and town limits³. The county’s zoning-district table lists base, planned-development, overlay and Estes Valley districts; the Land Use Code supplies detailed district standards³. Minimum lot size and maximum building height depend on the parcel's district and location⁶. Manufactured homes are a listed principal use in the county’s Manufactured Housing Park Preservation (MHP-P) district, but that does not make them allowed in every district¹⁹. Road setbacks are measured from the lot line, nearest road easement or right-of-way edge, or nearest traveled-way edge, whichever is greater; road setbacks apply on both sides even where a road crosses the lot³. Loveland also sets its own zoning²⁰. Wellington, Timnath, Estes Park, Johnstown, which reaches into Larimer County from Weld County, and Berthoud, which extends from Weld County into Larimer County, have their own zoning standards^{21,22,23,24,25}. Larimer County Health and Environment requires county septic permits; Johnstown also requires a town permit for private wastewater systems, with county and state requirements applying^4,26. For unincorporated parcels, contact Planning at planning@larimer.org or (970) 498-7679 to identify the district and overlays before choosing a home site⁶.

The Larimer County Department of Health and Environment issues septic permits; call the OWTS program at (970) 498-6775⁴. Building or fixing a septic system requires a permit, with separate types for new systems, repairs, sealed vaults and remodels or upgrades⁴. Before submitting a new-system septic application, complete soil testing, including inspection of 2 test pits; submit the soils report, design documents, plot plan and an engineer’s design if needed, and pay the fee with the application⁴. County staff then visit the site, check the test pits and review the soil report⁵. OWTS fees vary by permit type and appear on the application form⁹. A new-system septic permit applies when a sewer connection is unavailable within 400 feet; the applicable sewer district controls hookup requirements⁴. An OWTS permit is generally unavailable when the property line is within 400 feet of a sewer line unless an exception applies⁴. At a property transfer, a certified third-party inspector must inspect an onsite system and submit the report before closing unless an exemption applies²⁷. Only 13.3% of Larimer County soils are rated without severe limits for a conventional drain field, so make septic feasibility a purchase contingency²⁸.

A tiny home on wheels may serve as an accessory living unit in unincorporated Larimer County if fixed to a temporary foundation approved by the Building Division and compliant with accessory-living-area standards and building-permit requirements¹⁰. We could not confirm private-land residential RV occupancy or temporary-camping rules; ask Larimer County Planning about the parcel and proposed duration⁶. In Larimer County Natural Resources parks and open spaces, camping is limited to designated areas and no more than 14 days in a 30-day period²⁹. A qualifying cabin needs at least one habitable room of 70 square feet with minimum length and width of 7 feet, plus a permanent foundation, building permits and inspections⁸. Larimer County requires permits for vaults, composting toilets and vaulted privies; these limited-use systems generally cannot serve properties capable of full-time living unless a full OWTS is impossible or prohibited³⁰. Portable chemical toilets are allowed only during home construction or emergencies³⁰.

1. Ask County Planning to confirm the parcel's allowed residential use, zoning district, minimum lot size, maximum height, overlays and setbacks^3,6.
2. Establish the water source; a new groundwater well generally requires a Colorado Division of Water Resources permit³¹.
3. Determine whether sewer is available and plan wastewater management before obtaining a building permit; an onsite system requires soil testing and a county OWTS permit⁴.
4. Complete the homeowner certification if you will serve as the general contractor⁷.
5. Submit the residential building application and plans in hard copy⁵.
6. Request each required building inspection at the appropriate time, keeping work accessible and permit documents on site^7,11.
7. Obtain final inspection approval and the Certificate of Occupancy before occupying a new home⁹.

Confirm zoning, legal lot status and allowed use before relying on a seller's development assumptions; Larimer County regulates zoning and land division in unincorporated areas^6,32. For existing structures, ask the Building Division to check building-permit history: the county identifies historical permit dates and exceptions, including discretionary exemptions for some agricultural buildings, rather than a blanket farm-building exemption³³. We could not confirm complete county floodplain or driveway-access requirements; ask County Planning about the proposed site and access⁶. Rentals of 30 days or less require a county license, conversion building permit, life-safety inspection and Certificate of Occupancy in unincorporated Larimer County³⁴. The median property-tax bill is about $2,662 a year²⁸.