AHJ and mailing city are not the same thing
The authority having jurisdiction is the city, town, county, district, or other body that administers the applicable permit and inspection process for the project address. A familiar mailing city can include properties outside that municipality.
Confirm the parcel or address before relying on a neighboring city's permit checklist. Fort Collins-area, Windsor-area, Greeley-area, Johnstown-area, and other boundary locations can involve a different municipal or county authority than the name used in the mailing address.
Local contractor requirements differ
Northern Colorado does not use one universal local contractor-license process for municipal window and door projects. Some municipalities require a Town or City contractor license before permitting. Evans states that it does not issue contractor licenses but requires a business license. State licenses remain relevant to regulated electrical and plumbing trades.
A municipal requirement is not a claim that A-1 currently holds every possible local license. Current credentials should be confirmed for the project before work is represented or scheduled.
- Berthoud: The Town states contractors must be licensed before applying for a building permit. The Town accepts building permits through CommunityCore and reports adoption of the 2024 I-Codes. Project scope controls the permit path.
- Severance: Contractor licensing is mandatory for contractors performing work in Town. Building permits and contractor registration are handled online through Community Core; SAFEbuilt handles inspections.
- Longmont: Anyone performing contracting work inside the City must hold the appropriate Longmont contractor license. The D-19 specialty class covers replacement windows and glazing. The City lists window replacement as permit-required. Exterior window or door changes to a locally designated historic landmark can also require a Certificate of Appropriateness.
- Evans: Evans does not issue contractor licenses, but contractors doing business in the City need a current business license. Contractors submit permit applications electronically through CitizenServe. Verify the correct application for the actual window or door scope.
Fort Collins, Loveland, Windsor, and Greeley
Fort Collins: Confirm the license or registration path that applies to the contractor and project scope. The City publishes a windows, doors, and skylights permit path covering window replacements, exterior and sliding doors, new openings, egress windows, storefront, and overhead doors. Scope and address control the actual requirement.
Loveland: Use the City's current contractor and permit guidance for work inside municipal jurisdiction. Loveland publishes building FAQs addressing window and door work and inspections. The project address and scope determine the final path.
Windsor: Confirm current Town requirements and the authority for the exact address. The Town publishes building-permit information and window-replacement guidance. Windsor mailing addresses can cross municipal or county jurisdiction lines.
Greeley: Confirm City requirements for addresses inside Greeley; unincorporated Weld County uses a separate authority. The City and Weld County operate different permit and inspection processes. Verify jurisdiction before relying on a checklist.
Berthoud, Timnath, Johnstown, and Severance
Berthoud: The Town states contractors must be licensed before applying for a building permit. The Town accepts building permits through CommunityCore and reports adoption of the 2024 I-Codes. Project scope controls the permit path.
Timnath: Town contractor licensing is required before permit issuance. Contractors submit permits through CommunityCore and retrieve permit and inspection documents through CommunityConnect. Confirm the exact window or door path for the project type.
Johnstown: Contractors performing work for homeowners must be licensed by the Town. Johnstown explicitly lists replacing windows, window frames, and door frames among required residential permits and uses eTRAKiT for permit and license services.
Severance: Contractor licensing is mandatory for contractors performing work in Town. Building permits and contractor registration are handled online through Community Core; SAFEbuilt handles inspections.
Longmont, Wellington, Evans, and Milliken
Longmont: Anyone performing contracting work inside the City must hold the appropriate Longmont contractor license. The D-19 specialty class covers replacement windows and glazing. The City lists window replacement as permit-required. Exterior window or door changes to a locally designated historic landmark can also require a Certificate of Appropriateness.
Wellington: Contractors and subcontractors must hold a current Town contractor license before permitting. Wellington uses Community Core for online permitting. The Town reported on July 28, 2026 that its website and code resources were being updated after adoption of the 2024 I-Codes.
Evans: Evans does not issue contractor licenses, but contractors doing business in the City need a current business license. Contractors submit permit applications electronically through CitizenServe. Verify the correct application for the actual window or door scope.
Milliken: The Town requires contractor registration or licensing before permit issuance. Milliken uses CommunityCore and explicitly lists window replacement among counter permits.
Permit questions to resolve before ordering
Confirm the AHJ, permit category, whether the work is like-for-like or changes the opening, safety-glazing and emergency-escape conditions where applicable, structural work, energy or product documentation, historic-designation status, commercial occupancy, accessibility, egress, rated-opening requirements, submittals, inspections, and who keeps labels or documents available.
The authority having jurisdiction and approved project documents make the final determination. This guide is practical planning information, not legal advice or a guarantee that one requirement applies to every project.
Commercial projects use more than a residential permit checklist
Commercial work may be controlled by approved plans, specifications, door schedules, hardware sets, accessibility and egress requirements, rated-opening conditions, design-professional direction, special inspections, and trade responsibility matrices in addition to the local permit workflow.
A-1 installs and coordinates within its assigned labor-only pedestrian-opening scope. It does not claim engineering, code design, fire-door inspection or certification, or authority over the AHJ.
Source and update method
Each municipality record stores the official agency, contractor or business-license rule, window or door permit fact where published, official URL, verified date, and refresh priority. Wellington carries a high-priority freshness flag because the Town reported an active resource update on July 28, 2026.
Requirements can change after the dates shown. Use the official links below and confirm the current path for the actual address and scope immediately before the project.
