Residential Alteration / Addition / Remodel Permit in Centennial, Colorado

Centennial requires a residential alteration / addition / remodel permit for: Building permit required for removing/reconfiguring existing spaces, extending existing spaces, or renovating existing spaces to include additions, remodels, and decks that add to the building footprint, per the City's Building Permit Classifications page; Basement finish, additions, and temporary/accessory structures are reviewed under separate review-timeline tracks from general 'Alterations' (see reviewTimelineDays and tips); Design must meet Centennial's local amendments: 30 psf non-reducible roof snow load, 115 mph design wind speed; PDF plans and/or site plans required for additions and remodels; Homeowners may self-perform and pull their own permit only if they occupy the residence and submit a signed Homeowners Agreement/Affidavit. If your project isn't listed, confirm with City of Centennial Building Division (Community Development Department) at 303-754-3321 before starting work.

In Centennial, the published Building Permit Fee — valuation-based (same schedule as new construction) is: $23.50 minimum ($1-$500 valuation), scaling per the Building Permit Fee Schedule table. Additional published fees: Building Plan Review Fee — 65% of the Building Permit Fee. These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Additions are reviewed in 10 business days after the plan review fee is paid; decks, patio covers, and basement finishes are reviewed in 5 business days after the plan review fee is paid. Source: City of Centennial Building Permit Review Schedule.

You'll need: Building Permit Application. Depending on your project, Centennial may also ask for: Single Family Residential Addition Guide (PDF, 767KB); Single Family Basement Finish Guide (PDF, 1MB); Single Family Uncovered Decks and Porches Guide (PDF, 577KB); Single Family Residential Detached Garage Guide (PDF, 602KB); Residential Patio Covers and Carports Guide (PDF, 544KB). See the required-documents checklist on this page for details on each.

Centennial requires 3 inspection(s) for a residential alteration / addition / remodel permit, in order: Footing/Foundation, Framing, Final. Schedule each through City of Centennial Building Division (Community Development Department) (303-754-3321).

Apply through City of Centennial Building Division (Community Development Department) at Centennial Civic Center, 13133 E. Arapahoe Rd., Centennial, CO 80112. Phone: 303-754-3321, email: buildingdivision@centennialco.gov. Office hours: Monday - Tuesday: 8 a.m. - 5 p.m.; Wednesday: 9 a.m. - 5 p.m.; Thursday - Friday: 8 a.m. - 5 p.m. Workstations are available at the Building Division office for online portal use. 24-Hour Citizen Response Center: 303-325-8000.. Official information: https://www.centennialco.gov/Government/Departments/Building.

Centennial, Colorado has adopted: Colorado has no statewide mandatory building code for general construction; code adoption is a home-rule/local decision that varies by city and county. Applicants must confirm the specific edition and local amendments adopted by their own city — do not assume any other Colorado jurisdiction's adopted codes apply to Centennial. Source: City of Centennial Building Division page (jurisdiction-specific adopted-codes list, current as of this review).; Colorado HB22-1362 (Building Greenhouse Gas Emissions, signed June 2, 2022) establishes a statewide ENERGY-CODE FLOOR only (not a full building code): before July 1, 2026, municipalities and counties that update their building codes must adopt and enforce an energy code achieving equivalent-or-better efficiency than the 2021 IECC and the state Energy Code Board's model Electric and Solar Ready Code; on/after July 1, 2026 they must meet the Board's model Low Energy and Carbon Code. Centennial's currently adopted 2021 IECC satisfies this floor as of this review. Source: Colorado General Assembly, HB22-1362, https://leg.colorado.gov/bills/hb22-1362; Colorado HB24-1152 (effective June 30, 2025) requires 'subject jurisdictions' (which include Centennial as part of the Denver metro area) to allow at least one Accessory Dwelling Unit per single-family-zoned lot where single-family homes are allowed, removing owner-occupancy mandates, ADU-specific parking minimums beyond what the statute permits, and other historical barriers. Centennial's Land Development Code ADU provisions (Section 12-3-603(H)) implement this. Source: Colorado General Assembly, HB24-1152, http://leg.colorado.gov/bills/hb24-1152; 2021 International Building Code (IBC) — current adopted edition per City of Centennial Building Division; 2021 International Residential Code (IRC) — current adopted edition per City of Centennial Building Division; 2021 International Existing Building Code (IEBC) — current adopted edition per City of Centennial Building Division; 2021 International Energy Conservation Code (IECC) — listed among Centennial's 'Current Building Codes'; note the Building Division's separate FAQ page states the adopted energy code as '2018 IECC' — the Building Division's main Codes page (which lists 2021 IECC) is treated as the more current, authoritative statement for this record, but applicants should confirm the operative edition with the Building Division directly given this discrepancy between the City's own published pages. Source: City of Centennial Building Division page and Building Division FAQ (both centennialco.gov); 2021 International Fire Code (IFC) — enforced by South Metro Fire Rescue, not the City Building Division; fire permits/plan review must be applied for separately through South Metro Fire; 2021 International Fuel Gas Code (IFGC) — current adopted edition per City of Centennial Building Division; 2021 International Mechanical Code (IMC) — current adopted edition per City of Centennial Building Division; 2021 International Plumbing Code (IPC) — current adopted edition per City of Centennial Building Division (Colorado, unlike Montana, uses the IPC here, not the UPC); 2021 International Swimming Pool and Spa Code (ISPSC) — current adopted edition per City of Centennial Building Division; 2023 National Electrical Code (NEC) — current adopted edition per City of Centennial Building Division (supersedes the 2020 NEC cited in the City's older 2024 Photovoltaic Installation Guide handout); 2025 Colorado Wildfire Resiliency Code (CWRC) — adopted by City of Centennial; part of the statewide Wildland-Urban-Interface code framework administered by the Colorado Division of Fire Prevention and Control, with local adoption required for WUI-designated jurisdictions by April 1, 2026 and full compliance by July 1, 2026. Source: City of Centennial Building Division 'Current Building Codes' list; 2024 Centennial Property Maintenance Code — locally authored, adopted by City of Centennial (PDF on file with Building Division); 2017 ICC A117.1 Accessible and Usable Buildings and Facilities — referenced in the 2021 IBC as adopted by City of Centennial; Centennial Municipal Code Chapter 18 (Building Regulations) and the City's Land Development Code govern amendments, permitting procedure, and zoning overlays on top of the adopted I-Codes. Source: https://library.municode.com/co/centennial/codes/municipal_code?nodeId=CEMUCO_CH18BURE. Local amendments apply — see the Centennial overview page for the full list.