This summary has been prepared to provide a source of information for builders, contractors, developers and residents about City procedures for development of property under the City's Development Code.
Meeting City requirements for land development in Thornton requires an understanding of four basic elements. These are: zoning, conceptual planning, subdividing (also called platting), and development permitting. Zoning determines allowable land uses. Conceptual site planning establishes a concept for development of the property. Subdividing establishes legal building sites. Development permitting establishes that the site plan, architecture, landscaping, and certain other development aspects meet all City Codes.
The summary and the specific application sheets for any proposal are meant to be used in conjunction with the Development Code (Chapter 18 of the Thornton City Code), as a parallel source of information. If there are inconsistencies or conflicts that arise or are implied, then Chapter 18 controls.
A planner in the City Development Department will provide additional information and help you become familiar with the Development Code and the various processing procedures.
Download the Development Summary Information [PDF/117KB] guide.
Annexation is the process whereby land is brought into the jurisdiction of the City of Thornton. When land is annexed, it becomes eligible for all municipal services and is subject to City laws, regulations, and taxes. Annexation and the annexation process must conform to Title 31, Article 12 of the Colorado Revised Statutes, “The Municipal Annexation Act of 1965, as Amended”, as well as the City of Thornton annexation policies and other applicable City requirements.
The annexation process is completed with the recordation of an annexation map and approval ordinance with the County Clerk and Recorder. Initial zoning of property, upon annexation, is generally done concurrent with the annexation actions. Annexations are approved by the City Council after a public hearing, and after the publication of four consecutive notices of annexation, the first being published 30 days prior to the City Council’s public hearing. The applicant can negotiate an annexation agreement with the City prior to the submittal of the application. Any agreements, and the proposed zoning for the property to be annexed are a part of the annexation process.
The Conceptual Site Plan Review Process establishes the framework for development on a site. It also allows for the City and the Applicant to create unique criteria for development on a specific property. Conceptual Site Plan review and approval is required prior to or concurrent with the approval of zoning or rezoning or when a Subdivision Plat is required.
The approved Conceptual Site Plan is valid for a period of three years after City Council action. The purpose of the Conceptual Site Plan is to ensure:
- Compliance with zoning and other development regulations;
- Performance criteria and standards adopted by the City Council; and
- The achievement of quality development on the ground through the review of a Conceptual Site Plan that will represent the actual development to occur on the site.
- The conceptual site plan will be approved by Council, or per the administrative review process for qualifying economic development projects specified in the Code.
- Creation of unique criteria for development on a specific property.
A Development Permit is a review of the site plan, landscape plan and architectural design that ensures compliance with the zoning and design sections of the Development Code. A Development Permit is required before a building permit can be issued for any new construction or most renovation of buildings, with some limited exceptions, including:
- Buildings or additions with an area less than 480 square feet
- Manufactured homes located in the Manufactured Home zoning district
- Retaining walls under four feet in height, swimming pools, decks, fences, flagpoles or paving that does not change the non-permeable coverage of a site by more than five percent.
Otherwise, a Development Permit is required before a building permit can be issued that significantly changes the size, height, floor area, building materials, or architectural character of any existing building. Development Permits are approved administratively by the Planning Director. If a Specific Use Permit is required, the application is reviewed and approved by the Planning Commission.
A Development Permit is valid for three years. When the land proposed for development is not already subdivided, the applicant for a Development Permit can apply for a Development Permit and Subdivision Plat concurrently.
- Minor Development Permits General Checklist [PDF/1.6MB]
- Landscape Plans Residential Subdivision Checklist [PDF/6.9MB]
- Minor Development Permit Attached Garage Checklist [PDF/1.3MB]
- Minor Development Permit Detached Garage Checklist [PDF/1.4MB]
- Minor Development Permit Residential Addition Checklist [PDF/1MB]
- Minor Development Permit Artificial Turf [PDF/1.8MB]
- Minor Development Permit Eligible Facilities Request [PDF/566KB]
Residential driveway installations require a permit from Current Planning. Applications require a site plan. Driveways are applied for through the City View Portal. Instructions for applying can be found using the City View Portal Help webpage and opening "Driveway Permit - Residential" document.
If you require assistance applying or creating a site plan, please contact the Planner of the Day (POD) by calling 303-538-7295 or by emailing pod.info@thorntonco.gov
Driveway regulations are found on the Current Planning webpage under "Helpful Resources for Homeowners".
- Subdivision Plat Checklist [PDF/2.2MB]
- CAD Template
The zoning district classification of a property outlines the various land uses allowed for the property. If a use is not listed within a specific zoning district, then the proposed use is not allowed. Sections 18-186 through 18-201 of the Development Code give descriptions of the requirements for the zoning district and list the uses allowed in each district. If there is a conflict between the use chart in Section 18-230 and Sections 18-186 through 18-201, then Sections 18- 186 through 18-201 control.
Amendments to the zoning of a property may be proposed by City Council, City Staff or a property owner. Zoning Amendments may include a request to change the zoning district classification, for example a change from Single-Family Detached to Community Retail, or a change in the zoning district boundary. If the property is currently not within the City boundaries and is proposed for Annexation, a Zoning application is required to be processed concurrently.
The City Development Department provides research for any property located within the City of Thornton. You can obtain this information by requesting a Zoning Verification Letter. To obtain a zoning verification letter, a completed application and a $45.00 fee per parcel address are required. Once a request is submitted, the letter takes approximately 2-3 business days to complete. For more information, please call 303-538-7295 or email pod.info@thorntonco.gov.
Applicants requesting City approval of a service plan or intergovernmental agreement are required to use the City's current model service plan and intergovernmental agreement forms. Additionally, applicants shall submit all other required application information and fees as outlined in the application instructions.
Application Information and Forms
- Submittal and Payment Instructions
- Model Service Plan [PDF/2.7MB]
- Model Intragovernmental Agreement [PDF/256KB]
Application Deadlines
Each year, applications are due by:
- November 1st for May elections
- May 1st for November elections
Applications received after these deadline dates may not be reviewed in time for the specified election. Contact the City Development Department at 303.538.7295 for questions.
Metro District Changes Adopted in 2021
On October 12, 2021, City Council adopted an ordinance amending the City's model service plan, model intergovernmental agreement, and Chapter 66 of the City Code for metropolitan districts ('metro districts'). The changes are intended to: 1) ensure homeowners are adequately informed about metro districts and tax obligations; 2) set limitations to protect homeowners from excessive tax burdens; and 3) ensure metro districts remain a viable tool for developers to fund necessary and required infrastructure and services.