Building Permits & Inspections

Driveway Permits have moved!

All new driveway permits will be filed with the Planning & Zoning Division instead of Building Inspections. There are no significant changes with the process, but your portal application will look a little different. To apply, visit the CityView Portal as you normally would, but look for the link to "Apply for a Planning Permit" under the Planning Department heading. For more information, visit the Portal Help page.

Contact the Planner of the Day at 303-538-7295 or at pod.info@thorntonco.gov for assistance in applying for a driveway permit moving forward. 

This change applies to all NEW driveway permit applications. If you applied for a driveway permit through the building inspections division, you will finish out your permit with the building inspectors and permit technicians. Please call 303-538-7250 for assistance.

ATTENTION ALL HOMEBUILDERS

August 27, 2024

Effective September 1, 2024, all 3^rd party engineer letters for residential homes shall specifically address inspection of the following:

• Footing (placement and reinforcement)
• Foundation (placement and reinforcement)
• Perimeter Foundation Drains
• Connection of foundation drains to the underdrain
• Damp Proofing
• Void material installation (if applicable)

Stamped engineering letters must be uploaded to the portal prior to scheduling final inspections. Note that any special requests require prior approval from the Building Inspection Supervisor.

Attention All Roofing Installers

July 26, 2024

Effective immediately, all mid-roof inspections are done by testing photos, and final roof inspections are don virtually.  Please schedule all inspections prior to 3:30pm the prior business day through the portal.  If you're unable to schedule in advance, we offer same day inspections by calling 303-538-7430 between the hours of 8:30am - 3:30pm.  The permit must be issued before you schedule inspections.  Provide the cell phone of the onsite contact when submitting the request.  The morning of your inspection a building inspector will contact you by text between 8-9am to confirm your inspection.  Delays may occur due to volume on any given day.

    MIDROOF INSPECTIONS / Photo submittal (mid-roof inspection only)

    All of the following must be clearly visible on the photos:

• Address of project (show numbers on house)
• An approved underlayment
• Roof valley materials
• Starter course
• Metal flashing

• Nail pattern (6 nails per shingles)

  Picture of shingle wrapper showing approved shingles matching the roofing permit application.

  A text will be sent out with the status, wait for the text before closing the roof.  

  Text photos, address, and permit number to 303-550-9401 

  FINAL ROOF INSPECTION / Virtual Inspection

  Prior to the virtual inspection make sure you have the following:

• FaceTime or Google Meet app installed on your mobile device.
•  Wi-Fi connection (be sure the signal works outdoors as you will be asked to verify your address as part of the inspection).

• Visual access to approved shingles, nailing patterns on shingles and underlayment, flashing, drip edge, approved valley lining material, ventilation, etc. as described in the city of Thornton Roofing Standards.

  If at any time the inspector believes they cannot complete an inspection virtually due to poor signal, or other reason, they may require the inspection be rescheduled at a later date and/or in-person.

  Any special requests require prior approval from the Building Inspection Supervisor.

  Please refer to our Roofing Standards [PDF/121KB] for current inspection requirements.

Effective Jan. 1, 2025

Water meter fees for residential and commercial projects will be charged at the time the building permit fees are collected.

Please email Developmentfees@thorntonco.gov or call 303-538-7370 with questions on fee rates,  or refer to water rates on our website:   https://www.thorntonco.gov/city-services/utility-billing/hydrant-meter-water-sewer-rates

• Single-Family Addition
• Fence Design Standards/Sight Distance Guide [PDF/149KB]
• Manufactured Home Handout [PDF/283KB]
• Single-Family Patio Covers and Carports
• Single-Family Uncovered Decks and Porches
• Pole Barn Construction
• Single-Family Ramp Construction
• Unheated Single-Family Enclosing Existing Patio Cover
• Single-Family Detached Garage
• Single-Family Basement Finish with Fireblocking [PDF/0.9MB]
• Roofing and Reroofing Guide

• Terminado de Sótano de una Residencia Familiar [PDF/871KB]
• Adición a una Residencia Familiar [PDF/438KB]
• Cubierta del Patio-Cochera [PDF/1.2MB]
• Encerramiento de un Porche [PDF/1.1MB]
• Garaje Separado de una Residencia Familiar [PDF/543KB]
• Patios y Porches descubiertos de una Residencia Familiar [PDF/1.9MB]
• Retejado de una Residencia Familiar [PDF/527KB]
• Informacion para Casa Prefabricada (Casa Mobil) [PDF/216KB]
• Requisitos para Entrada de Coche (Driveway) [PDF/62KB]

• Building Permit Report April 2025
• Building Permit Report March 2025 [PDF/386KB]
• Building Permit Report February 2025 [PDF/279KB]
• Building Permit Report January 2025
• Building Permit Report December 2024
• Building Permit Report November 2024 [PDF/430KB]
• Building Permit Report October 2024
• Building Permit Report September 2024
• Building Permit Report August 2024
• Building Permit Report July 2024 [PDF/1.3MB]
• Building Permit Report June 2024
• Building Permit Report May 2024

We have resumed in-person inspections within occupied structures and will attempt to accommodate the homeowner based on their comfort level with in-person inspections. If a virtual inspection is preferred, please clarify such when scheduling the inspection (**see virtual inspection guidelines below). We will continue to provide in-person inspections for work being done outside of the occupied structure (i.e. fences, detached garages, etc.).

The following is a list of what we believe could be inspected via virtual inspection in an occupied structure: caisson, footing, stem wall, water heater, furnace, AC, rough inspections, drywall, final inspections, final deck/ patio cover, driveway, and fence.

All Roof inspections and Solar PV inspections will be done virtually. Onsite contact information must be provided when scheduling.

Basement finish re-inspections may be scheduled for virtual inspection and will be left to the discretion of the inspector whether an inspection can be completed.

The exception to this rule will be when there is an inspection that is specifically related to safety/health in occupied structures.

Before scheduling a virtual inspection, please verify you have the following:

• Facetime or Google Meets app installed on your mobile device,
• Wi-Fi connection (be sure the signal works outdoors as you will be asked to verify your address in the video)
• Have inspection tools available (tape measure, level, flashlight, GFCI capable outlet tester, step ladder)
• When scheduling the inspection, provide name and phone number of the person operating the camera. If this information is not provided the inspection will be automatically canceled and you will need to reschedule it.

NOTE: If at any time the inspector believes they cannot complete an inspection virtually due to poor signal, or other reason they may require the inspection be rescheduled at a later date and/or in-person.

Required only for Commercial, Multi-family, and Single Family Attached Shell Permits. To begin the routing process please call 303-538-7250 one week prior to requesting final inspections.

The City of Thornton has amended the roofing sections of the International Building Code and the International Residential Code to require asphalt shingles to carry a manufacturer's national wind warranty for the City’s designated wind speed of 90 mph 3-Second Gust. Please see our Roofing Standards [PDF/121KB] for a list of approved shingles and other roofing requirements.  

Please read the Roofing Inspection Policy effective 7/26/2024.

A building permit is required any time you erect, construct, enlarge, remodel, alter, repair, move, improve, remove, convert, demolish, or change the type of occupancy of any building, structure or utility. For a list of projects that require a permit and a list of projects that do not require a permit, click on the Building Permit Requirements link listed under the Permits, License Application section of links.

The process to obtain a permit will vary dependent upon the complexity of the project.  It is our goal to get plans through the system and a permit issued in the minimum amount of time possible.

Once you have all of the information gathered for a complete submittal package the application and plans can be submitted electronically through the CityView Portal.  Refer to the Submittal Requirement links on the right hand panel for more information.

The amount of time to process and review a plan from the initial submittal date to the completion of the first review (the turn around time) will vary with the type of project. Delays may occur due to high volume of applications.

• New Commercial -  18  working days or less
• Commercial Tenant Improvements & Remodels - 13 working days or less
• New Residential except multifamily - 13 working days or less
• Residential Remodels and Misc. - 8 working days or less

Once all approvals have been completed, the application is prepared for permit issuance by the permit technician staff.  They will verify that all contractors are currently licensed, all permission forms have been received and calculate the permit fee.  Once this is complete, you will be notified that the permit is ready for issuance.  Following payment of fees, you can access the building permit, required inspection and the approved plans by accessing the permit in the online portal.

Adopted Codes for the City of Thornton

• 2021 International Building Code
• 2021 International Residential Code
• 2021 International Plumbing Code
• 2021 International Mechanical Code
• 2021 International Fuel Gas Code
• 2021 International Existing Building Code
• 2021 International Energy Conservation Code
• 2021 International Swimming Pool and Spa Code
• 2021 International Fire Code
• 2020 National Electric Code

1.  2021 International Building Code.

2.  2021 International Residential Code.

3.  2021 International Plumbing Code.

4.  2021 International Mechanical Code.

5.  2021 International Fuel Gas Code.

6.  2021 International Energy Conservation Code.

7.  2021 International Existing Building Code.

8.  2021 International Fire Code.

9.  2020 National Electric Code.

10.  ICC A117.1-2017 Accessible and Usable Buildings and Facilities.

*  Current codes are effective June 1, 2023

• Climatic and Geographic Design Criteria [PDF/83KB]