Contractor Information

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 primary residence are not considered contractors and are not required to obtain a contractor license.

Applicants for Class A General, Class B Building, Class C Residential, Class D Mechanical  and Class D Roofing License are required to provide proof that they are qualified to perform the work under that License Class. The City currently accepts a current valid contractor license from a reciprocating jurisdiction or a Contractor License Certification from the International Code Council for the currently adopted code. For the requirements of each License and for a list of jurisdictions that we reciprocate with, please refer to the Contractor License Application Packet below. 

Hiring a Contractor 

The key to hiring a contractor, whether it’s a roofing, remodeling or new construction contractor, is to do your homework. The following tips should help you find a reputable and reliable contractor to successfully complete that home renovation or repair.

  • Use local established companies. (Beware of the door to door contractor.) 
  • Only hire a contractor that is licensed or can obtain a Contractor License with the City of Thornton. Beware of a contractor that asks you to get the building permit, they may not be licensed.
    • Note: The City of Thornton requires all contractors to be licensed prior to issuance of a building permit.
  • Ask for and check the contractor’s references. Choose a project similar to yours and ask these types of questions of the former client: 
    • May I visit your home to see the finished project?
    • Was the work completed on time and in accordance with the terms of the contract?
    • Did workers show up on time?
    • Did they keep the project area clean and safe?
    • Were there any unexpected costs?
    • Did the contractor keep you informed as the project progressed?
    • Are you satisfied with the project?
    • Would you hire this contractor again?
    • Would you recommend the contractor?
  • Get several written bids for the project, 3 is the usual number but don’t hesitate to get more if the numbers don’t seem right or they are miles apart.
  • Don’t always choose the lowest bid, they could be looking to cut corners, use substandard products or make up the difference through change orders. 
  • Check with the Better Business Bureau to see if any complaints have been filed. You can also check a contractors’ status with the Building Inspection Division (303-538-7250). 
  • Make sure the contractor gets a building permit. This is their responsibility as the project manager and please don’t take their word for it, make them produce the Permit and post the Inspection Card. 
    • Note: If you decide to obtain the permit you become responsible for the entire project including worker’s compensation and builders liability.
  • Put everything in writing, including all details and verbal promises, specific materials to be used, start and completion dates, payment schedule and a penalty clause for failure to complete the project on time. Make sure all sections of the contract have been completed. Be sure to include a requirement that the contractor obtain lien releases from all suppliers and subcontractors. This will protect you if the contractor fails to pay the bills. 
  • Make sure the contractor carries liability insurance and workers compensation, this protects you should someone be injured on the project site. 
  • Never pay in full before the job begins. Always hold back 15 to 20 percent of the total contract price until you are satisfied with the job and all inspections have been approved. 
  • For more information on hiring a contractor search the web for “How to hire a contractor”.