Centennial building permits

Tips & gotchas

• Colorado has NO statewide mandatory building code for general construction (unlike Montana). Code adoption is entirely a home-rule/local decision — always confirm the specific edition and amendments for the exact city or county in question rather than assuming a neighboring Colorado jurisdiction's codes apply.
• Colorado's only statewide floor is an ENERGY code floor (HB22-1362): by July 1, 2026 all municipalities/counties that update codes must meet or exceed the 2021 IECC plus the state's model Electric and Solar Ready Code; after that date, the state's model Low Energy and Carbon Code becomes the floor. Centennial's currently adopted 2021 IECC satisfies the pre-2026 floor.
• Colorado's HB24-1152 (effective June 30, 2025) requires Denver-metro 'subject jurisdictions' including Centennial to allow at least one ADU per single-family lot; Centennial's Land Development Code Section 12-3-603(H) implements this.
• ISSUING ARRANGEMENT: Building permitting in Centennial is performed directly by City of Centennial staff (Building Division, part of Community Development) — NOT by an outside private contract building department, based on the City's current published Building Division pages (contact: buildingdivision@centennialco.gov, City-staffed office at the Civic Center). Centennial has historically run a broader 'contract city' model for many OTHER municipal services (e.g., public works contracted to Jacobs Engineering, formerly CH2M Hill), which is documented in third-party commentary (e.g., Reason Foundation), but that history does not appear to extend to the Building Division as of this review. Fire-code (2021 IFC) plan review/permitting IS carved out to South Metro Fire Rescue, a separate special district — this is the one confirmed non-City AHJ carve-out, applying to all fire code matters including commercial solar installations.
• DISCREPANCY FLAGGED: The City's main Building Division 'Current Building Codes' list shows 2021 IECC and 2023 NEC, while the Building Division's own separate FAQ page states '2018 EICC' and the 2024 Photovoltaic Installation Guide PDF references the 2020 NEC and 2015 International Codes. This record treats the main Codes page as authoritative (most specific and prominently maintained), but applicants should confirm the exact operative edition with the Building Division (303-754-3321) at time of application, since the City's own pages are not fully internally consistent.
• Centennial's Building Permit Review Schedule gives category-specific business-day timelines (One-Stop = 1 day; Reroof/Demolition/Renewable Energy = 5 days; Alterations/Basement Finish/Deck/Miscellaneous = 5 days; Additions/Temporary-Accessory/Pool = 10 days; New Build Residential/Commercial/Multi-Family = 15 days), all measured from the day the plan review fee is paid, NOT from submittal. First-comment timelines begin upon receipt of a COMPLETE submittal; incomplete submittals do not start the clock.
• One-Stop Permits (AC new/replacement, furnace, water heater, electric service change, gas line, irrigation line, residential sewer line replacement, residential-only reroof, and windows/doors with no structural changes) require NO plan review and are issued the same business day ('over the counter').
• Building Permit Fees are valuation-based on a sliding scale ($23.50 minimum up to $1.00-$500.00, scaling to $5,608.75 + $3.15/$1,000 above $1,000,000). Plan review fees are a separate additional charge of 65% of the building permit fee. Electrical fees for residential living space use a DIFFERENT square-footage-based table; all other electrical work (including PV) uses an installation-VALUE-based table.
• Centennial's local structural design amendments: 30 psf NON-REDUCIBLE roof snow load, 115 mph design wind speed (Exposure Category C for solar calculations), and a residential window U-factor of 0.30 — all documented on the Building Division FAQ page and echoed in the Photovoltaic Installation Guide.
• A mandatory mid-roof inspection applies to ALL reroofing permits (residential and commercial); three documented fallback options exist if it is missed (photo waiver, partial tear-off inspection, or engineer's letter) — this is a distinctive Centennial requirement worth flagging prominently to contractors.
• Homeowners may self-perform work and pull their own permit ONLY if they occupy the residence and sign a Homeowners Agreement/Affidavit; any contractor/subcontractor used must independently hold a City of Centennial contractor license.
• Colorado uses the International Plumbing Code (IPC), not the Uniform Plumbing Code (UPC) used in some neighboring Mountain West states.
• The City does not appear to publish itemized per-fixture plumbing fee tables or per-appliance mechanical fee tables (unlike, e.g., Billings, MT) — plumbing and mechanical permits are fee'd on the same general valuation-based Building Permit Fee Schedule. This is flagged as a data gap, not an invented fee.
• A demolition-specific standalone checklist/application PDF was not located as a distinct document separate from the general Building Permit Application; recovery attempts (browser-header curl, no-header curl, targeted URL guesses against the building-guide PDF path, and a full inventory of every guide/checklist PDF linked from the Building Division main page) did not surface one — confirmed genuinely unpublished. The demolition PERMIT TYPE is fully verified: Residential Demolition and Commercial Demolition are each explicitly named (by name, not as a generic catch-all) in the Building Permit Review Schedule's 5-business-day tracks, and the general valuation-based Building Permit Fee Schedule governs fees.
• ADU review timeline is 5-10 business days after the plan review fee is paid, VERIFIED against named rows of the City's Building Permit Review Schedule via each ADU type's own City guide PDF: an Interior/Internal-Conversion ADU is an alteration/basement-finish conversion (5 business days per the Review Schedule's 'Alterations, basement finish, deck/pergola/patio cover, demolition, miscellaneous...' residential row); an Attached ADU is an addition and a Detached ADU is a new accessory structure (both 10 business days per the Review Schedule's 'Additions, temporary or accessory structures and swimming pool/spa' residential row). The Attached ADU guide is literally titled 'ADU ADDITION' and the Detached guide describes a structure 'entirely detached or separated' — so the category mapping is grounded in the City's own guide definitions, not inferred, and each endpoint is a City-published figure. All other ADU substantive requirements (zoning, size, setbacks, parking, registration) are independently verified from the City's ADU page.
• 2025 Colorado Wildfire Resiliency Code has been adopted by Centennial per its Current Building Codes list; statewide WUI-designated jurisdictions have until April 1, 2026 to adopt and July 1, 2026 to be fully compliant, per the Colorado Division of Fire Prevention and Control.