Skip to main content
PermitBase

Change of Use (Business Change of Certificate of Occupancy) in Thornton, Colorado

Thornton does not have a permit literally named “Change of Use Permit.” Its functional equivalent is the Business Change of Certificate of Occupancy (Business Change of CO) process, administered by the Building Inspection Division through the CityView Portal, which covers a change of building ownership, change of business ownership, change in business name, and change of use in a building (e.g., retail to restaurant, a new business into an existing or vacant space, or a new business sharing space with an existing business) — provided there are NO construction modifications to the tenant space. If construction modifications are needed (walls, MEP work, kitchen equipment change-out), a Tenant Improvement permit is required instead, and Change-in-Use applications are reviewed case by case to determine which path applies.

Verified 2026-08-14 · Source

When you need this permit

  • Applies to a change of building ownership, change of business ownership, change in business name, or change of use in the building (e.g., retail to restaurant, new business into an existing/vacant space, new business sharing space with an existing business), provided there are NO construction modifications to the tenant space
  • If there are or will be construction modifications (building/removing walls; electrical, mechanical, or plumbing additions/deletions/alterations; kitchen equipment change-out), a Tenant Improvement permit is required instead of a Business Change of CO
  • Applications classified as a Change in Use are reviewed case by case by the Building Inspection Division to determine whether a Tenant Improvement permit is required instead
  • A floor plan must be uploaded showing the dimensions of the space, all interior partition walls, the location/size of all exit doors, and a label of each room's use including restrooms (plus a building layout/key plan for multi-tenant buildings showing suite/unit numbers)
  • Submitted online via the CityView Portal as a ‘Business Change of CO’ application type under the Building Department
  • Both the Building Inspection Division and the Fire Department conduct inspections before a Certificate of Occupancy is issued (e.g., exit/bathroom signage, emergency lighting, exit doors, corridor obstructions, mechanical/electrical/plumbing code issues; a Tri-County Health inspection report is required for food service businesses)
  • Businesses equipped with a Fire Alarm, Fire Sprinkler, or Hood (kitchen suppression) System must provide proof of annual testing, maintenance, and inspection within the past 12 months as part of the Fire Prevention Certificate of Occupancy checklist
  • New businesses and businesses occupying a new space must obtain a Certificate of Occupancy before opening to the public
  • A separate Sign Permit is required if the business is replacing or installing new signs, or placing banners/temporary signs
  • A business license must also be obtained through the City's Sales Tax office

Required documents

Check off what you have — your progress is saved on this device.

Not ready yet — 0 of 2 required documents checked.

This checker covers one permit. A full project usually triggers several — our checklist will assemble all of them, free →

Fee schedule

Business Change of Certificate of Occupancy Application FeePer the City's Business Change of Certificate of Occupancy Process guide; payable online once the application has been reviewed and approved.
$25.00

Review timeline

Plan reviewThornton’s published plan-review target
1–10 business days

How long did your Change of Use (Business Change of Certificate of Occupancy) permit actually take in Thornton?

Anonymous — one question, no email. Answers are combined and only shown once at least 5 people have reported.

Inspection process

  1. 1

    Building Inspection (Change of Occupancy)

    Checks exit/bathroom signage, emergency lighting, exit doors, corridor/hallway obstructions, and mechanical/electrical/plumbing code issues; food service businesses must submit a Tri-County Health Inspection Report prior to final inspection

  2. 2

    Fire Prevention Inspection (Change of Occupancy)

    Checks Knox Box access, occupant load posting, fire lane/hydrant clearance, means of egress, and fire extinguisher service; businesses with an existing Fire Alarm, Sprinkler, or Hood System must show proof of testing/inspection within the past 12 months

See the full Thornton inspection guide — scheduling & re-inspection fees →

Tips

  • If your new use requires ANY construction work — even minor wall changes or MEP alterations — the City redirects you from the $25 Business Change of CO application to a full Tenant Improvement permit, which is reviewed and fee'd very differently. Confirm scope before applying.
  • Both Building Inspection AND Fire Prevention must sign off before your Certificate of Occupancy issues — if your space has an existing fire alarm, sprinkler, or kitchen hood system, have your annual testing/inspection report ready (dated within the past 12 months) or the Fire inspection will fail.
  • Changing or adding signage as part of your business change requires a SEPARATE Sign Permit application — it is not bundled into the Business Change of CO process.

Frequently asked questions

Thornton requires a change of use (business change of certificate of occupancy) permit for: Applies to a change of building ownership, change of business ownership, change in business name, or change of use in the building (e.g., retail to restaurant, new business into an existing/vacant space, new business sharing space with an existing business), provided there are NO construction modifications to the tenant space; If there are or will be construction modifications (building/removing walls; electrical, mechanical, or plumbing additions/deletions/alterations; kitchen equipment change-out), a Tenant Improvement permit is required instead of a Business Change of CO; Applications classified as a Change in Use are reviewed case by case by the Building Inspection Division to determine whether a Tenant Improvement permit is required instead; A floor plan must be uploaded showing the dimensions of the space, all interior partition walls, the location/size of all exit doors, and a label of each room's use including restrooms (plus a building layout/key plan for multi-tenant buildings showing suite/unit numbers); Submitted online via the CityView Portal as a ‘Business Change of CO’ application type under the Building Department; Both the Building Inspection Division and the Fire Department conduct inspections before a Certificate of Occupancy is issued (e.g., exit/bathroom signage, emergency lighting, exit doors, corridor obstructions, mechanical/electrical/plumbing code issues; a Tri-County Health inspection report is required for food service businesses); Businesses equipped with a Fire Alarm, Fire Sprinkler, or Hood (kitchen suppression) System must provide proof of annual testing, maintenance, and inspection within the past 12 months as part of the Fire Prevention Certificate of Occupancy checklist; New businesses and businesses occupying a new space must obtain a Certificate of Occupancy before opening to the public; A separate Sign Permit is required if the business is replacing or installing new signs, or placing banners/temporary signs; A business license must also be obtained through the City's Sales Tax office. If your project isn't listed, confirm with City of Thornton — City Development, Building Inspection Division at 303-538-7250 before starting work.

$25.00 for the application, with processing of up to 10 working days (may vary with application volume), per the City's Business Change of Certificate of Occupancy Process guide.

Thornton's published plan-review target for a change of use (business change of certificate of occupancy) permit is 1–10 business days.

You'll need: Business Change of Certificate of Occupancy Application (CityView); Floor Plan. Depending on your project, Thornton may also ask for: Building Layout / Key Plan. See the required-documents checklist on this page for details on each.

Thornton requires 2 inspection(s) for a change of use (business change of certificate of occupancy) permit, in order: Building Inspection (Change of Occupancy), Fire Prevention Inspection (Change of Occupancy). Schedule each through City of Thornton — City Development, Building Inspection Division (303-538-7250).

Apply through City of Thornton — City Development, Building Inspection Division at 9500 Civic Center Drive, Thornton, CO 80229. Phone: 303-538-7250, email: buildings@thorntonco.gov. Office hours: Mon–Fri, 8:00 a.m.–5:00 p.m. (counter payments 8:00 a.m.–4:30 p.m.). Official information: https://www.thorntonco.gov/business-development/city-development/building-permits-inspections.

Thornton, Colorado has adopted: 2024 International Building Code (IBC) — with Thornton amendments; adopted by ordinance May 13, 2025, effective July 1, 2025 (replaced the 2021 IBC); 2024 International Residential Code (IRC) — with Thornton amendments (Table R301.2 climatic/geographic design criteria repealed and reenacted with Thornton-specific values); effective July 1, 2025; 2024 International Plumbing Code (IPC) — with Thornton amendments; effective July 1, 2025; 2024 International Mechanical Code (IMC) — with Thornton amendments; effective July 1, 2025; 2024 International Fuel Gas Code (IFGC) — with Thornton amendments; effective July 1, 2025; 2024 International Energy Conservation Code (IECC) — adopted in full (residential provisions); includes Colorado Model Electric Ready and Solar Ready Code per HB22-1362; effective July 1, 2025; 2024 International Existing Building Code (IEBC) — with Thornton amendments; effective July 1, 2025; 2024 International Swimming Pool and Spa Code (ISPSC) — adopted by reference; effective July 1, 2025; 2023 National Electrical Code (NEC) / NFPA 70 — Thornton adopts the NEC edition currently adopted by the State of Colorado automatically and simultaneously (Thornton City Code Sec. 10-162); matches the statewide electrical code; 2021 editions of the above I-Codes and the 2017 NEC — the prior code cycle, superseded for new submittals as of July 1, 2025 but referenced for projects permitted under it (e.g., the city's 2023-dated Solar PV submittal-requirements handout still cites 2020 NEC/2021 IRC/2021 IBC/2021 IFC and should be read as superseded by the current 2024/2023 code cycle for design-code citations). Local amendments apply — see the Thornton overview page for the full list.

Not by that name. Thornton's equivalent is the Business Change of Certificate of Occupancy (Business Change of CO) process, administered by the Building Inspection Division via the CityView Portal, for a change of use or new tenant in an existing space with no construction modifications. Projects requiring construction changes are redirected to a Tenant Improvement permit instead.

Sources & verification

Verified against official sources. Last reviewed 2026-08-14.

Fees, timelines, and adopted codes are researched from each jurisdiction's published records — see how we verify. Requirements change and vary by project, so always confirm the current details with the Thornton building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.

Other permits in Thornton

Residential Building Permit (New Construction)Residential Addition / Remodel PermitElectrical PermitPlumbing PermitMechanical / HVAC PermitRoofing Permit (Reroof)Solar PV PermitElectric Vehicle (EV) Charging Station PermitAccessory Dwelling Unit (ADU) PermitDemolition PermitCommercial Tenant Improvement PermitDeck / Covered Patio PermitSign PermitFire Sprinkler / Fire Alarm System Permit

Change of Use (Business Change of Certificate of Occupancy) in other cities

Akron, ColoradoAlamosa, ColoradoArvada, ColoradoAspen, ColoradoAult, ColoradoAurora, ColoradoAvon, ColoradoBasalt, Colorado

Compare change of use (business change of certificate of occupancy) fees across Colorado →

Look up this fee in a different city →

Embed this data card →

Now live

Build your Thornton project checklist

Describe your project once and get every permit, document, and fee it triggers in Thornton — in one checklist. Sign up and pay once to generate it, or go unlimited with Pro.

Get started →