Thornton issues a variety of building, development, and infrastructure permits. Please ensure that you select the proper type of permit prior to completing your application. Contact us if you have any questions.

Permitting Notices

  • Minimum fee for any right-of-way construction permit associated with franchise or pursuant to any type of right-of-way use agreement: $250ea.
  • Operating without a permit. Any person found to be conducting any construction activity, work, or excavating activity without having first obtained any type of construction permit or other required permits, shall immediately cease all activity (exclusive of actions required to stabilize the area), and be required to obtain all applicable permits before the project may be restarted. An additional surcharge shall be set by resolution of the city council.

Building Permit Application

If you have any questions please call Building Inspections at 303-538-7250, or email buildings@thorntonco.gov. Additional information is available at the Contractor License page.

Building Permit

A building permit is required anytime a homeowner or contractor erects, constructs, enlarges, remodels, alters, repairs, moves, improves, removes, converts, demolishes, or changes the type of occupancy of any building, structure or utility.

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Contractor License Application

If you have any questions please call the Building Inspection Division at 303-538-7250, or email buildings@thorntonco.gov. Additional information is available at the Building Inspection Division page.

Contractor License

The City of Thornton requires licensing for all contractors involved in the construction, alteration, remodeling, repairing and equipping of buildings and structures; installation of underground utilities; construction of roads and streets and construction of all City-owned water, sewer, and storm drainage facilities. Homeowners doing work on their personal private residence are not considered contractors and are not required to obtain a contractor license.

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Infrastructure Permit Applications

Additional information is available on the ID ROW Permit page. If you have any questions please email Infrastructure.Permits@ThorntonCo.gov or call 720-977-6210.

CIP Permits

Right of Way construction permit application for work related to Thornton capital improvement projects.

Franchise Permits

Right of way construction permit application for work being done for franchisees (Comcast, United Power, Xcel)

General Permits

Right of way construction permit application for projects not related to CIP, Franchise, Water/Sewer service repair, or Chase Drain installation/Curb Cuts.

Sewer / Water Service Repair Permits

Sewer service and water service repairs extending from the yard to the right-of-way within City limits, or in-yard only when outside City limits. Repairs being done in-yard only within City limits must obtain permit from Buildings Division.

Non-Construction Related Permits

Traffic control permit application for special events, on-street containers, oversize vehicles, and volunteer work.

Floodplain Development Permit

If you have any questions please call the City Development office at 303-538-7295, or email developmentsubmittals@thorntonco.gov. Please follow the Development Submittal Instructions when submitting a Floodplain Development Permit application.

Floodplain Permits

The City of Thornton requires a Floodplain Development Permit (FDP) to evaluate any and all impacts of activities proposed in the City's floodplains.

Hydrant Meter Rentals

Hydrant Meters no longer processed through City Development

Please be advised that the hydrant meter rentals are now being processed through Utility Billing as of April 14, 2024.

For information on how to obtain a meter, please visit their website located here. The hydrant meter information is located on the right-hand side of the page.

For any questions or concerns, please email HydrantMeterRental@ThorntonCO.gov. or you may call utility billing directly at 303-538-7370.

General City Development Fees

Use the link below when directed to make a general fee for City Development. If you have any questions regarding making a general payment, please email us at CityDevelopment@ThorntonCO.gov or call at 303-538-7295.

Development Permit Applications

If you have any questions please call the City Development office at 303-538-7295, or email permits@thorntonco.gov. Additional information is available at the Development Engineering page.

New and Re-development Permits

Permits for new development, redevelopment work.

Please read each description below as a few of the application processes below have changed before applying for your permit to avoid having to reapply.

For construction and traffic permits of new development and re-development projects within the city, please follow the instructions on the Development Construction and Traffic Permits page.

For Development Engineering ROW permits and Development Traffic Control Permits (New Process effective November 3, 2025)

Construction permits and landscaping permits for new or re-development of a property and for parking lot repairs. (Not for Franchise company use - United Power, Xcel, Comcast and etcetera).

If you are needing a permit for work that is for a Capital Improvement Project (“CIP”) for the City of Thornton, work in the City that is not related to a new development site or redevelopment site or non-construction related items, please use the applications on the left hand side of this page under the Infrastructure Permit Applications Section. These applications are for active Development Projects Permits ONLY.