The specific permit, cost, licensing, and safety questions Denver homeowners ask before starting a remodel, ADU, or addition. CPD permits, the 2023 Group Living Amendment, Colorado's no-state-GC-license quirk, hail/Class-4 roofing, altitude concrete curing, and 2026 pricing — all answered with Denver specifics, not national averages.
Yes for any work involving electrical circuit changes, plumbing relocation, gas line work, or wall removal. Denver Community Planning and Development (CPD) issues residential permits through the e-permits portal. Like-for-like cosmetic swaps (cabinets, counters, paint, flooring with no subfloor change) are permit-exempt. Plan-review for a kitchen Long Form runs 3-6 weeks. Denver is one of the few major metros where the city issues residential permits but Colorado does NOT issue a state-level general contractor license — your contractor needs a Denver Class A, B, C, or D supervisor certificate plus a Class III General Contractor license issued through CPD.
Denver ADU plan-review runs 8-14 weeks under the 2023 Group Living Amendment, which legalized ADUs citywide. Detached ADUs and attached/internal ADUs both require a Site Development Plan (SDP) review with CPD and Denver Public Works coordination for sewer-lateral and right-of-way work. Historic Denver districts (Curtis Park, Five Points portions, Country Club, 7th Avenue) add a Landmark Preservation Commission review of 30-60 days. Permit fees on a typical ADU run $4K-$9K. Construction and tap fees can add another $8K-$18K depending on whether you need a new sewer service.
Denver's 2018 Slot Home text amendment ended the slot-home pattern (narrow side-by-side townhouses on flag lots) by requiring street-facing entries, primary façades on the street, and a maximum 60% lot coverage. The 2023 Group Living Amendment then allowed up to 5 unrelated adults per household and legalized ADUs in all residential zones. If you're adding an ADU, doing an addition that changes building form, or converting a single-family to a duplex, you'll route through Site Development Plan review. Build-form rules are stricter in Urban House (U-SU) zones than in Mixed-Use (U-MX) zones — pull your zone code from the Denver Maps tool before scoping.
Denver ranges in 2026: $40K-$75K for a mid-range kitchen (semi-custom cabinets, quartz, KitchenAid-tier appliances, same footprint), $80K-$155K for a full gut with custom cabinetry and Sub-Zero/Wolf appliances, and $170K+ for chef-grade with structural changes. Permit fees on a typical Denver kitchen run $1,200-$3,500. Trade labor is $80-$120/hr. Cherry Creek, Country Club, and Wash Park homes add 10-15% premium. Mountain-influenced builds incorporating reclaimed timber, stone, and steel run higher than coastal-style modern builds because of material sourcing and custom fabrication.
$185K-$420K all-in for a typical 600-1,000 sq ft detached ADU in Denver. Garage conversions are cheaper at $115K-$240K. Drivers of variance: lot access (alley vs front-yard delivery), utility connections (new sewer lateral $12K-$22K, new electrical service $6K-$10K), and Denver Water tap fees ($8K-$15K depending on meter size). Foundation costs run higher than coastal metros due to expansive bentonite clay soils requiring caisson piers in many neighborhoods (Park Hill, Stapleton/Central Park, southwest Denver). Budget $5K-$8K in geotech and structural engineering on top of standard architectural fees.
Full-gut renovations in Denver run $300-$550 per square foot in 2026. A 2,000 sq ft Wash Park bungalow gut typically lands at $600K-$1.1M including soft costs and permits. Pre-1950 Denver bungalows almost always need foundation underpinning ($25K-$80K) for expansive-soil-related cracking, and 1920s-1940s homes often have knob-and-tube electrical that triggers a full house rewire. Sewer scope inspection is non-negotiable — clay sewer laterals from the 1900-1960 era frequently fail and replacement runs $8K-$25K in Denver because of city right-of-way restoration requirements. Budget 18-22% contingency on any pre-1960 stock.
Colorado is one of the few states with NO state-level general contractor license. All licensing happens at the municipal level. In Denver, a residential contractor needs a Denver Class III General Contractor license issued by Community Planning and Development, plus a registered Class A, B, C, or D Supervisor Certificate (the actual person responsible on site). Verify both at denvergov.org/contractor-search. Trade contractors (electrical, plumbing, mechanical) need their state Colorado license from DORA Division of Professions and Occupations PLUS a Denver registration. If your project is in Aurora, Lakewood, Englewood, or unincorporated Jefferson/Arapahoe county, that municipality issues its own contractor license separately — Denver's license does not transfer.
Colorado law leaves residential general contracting unregulated at the state level — only trade-specific licenses (electrical, plumbing, HVAC, mechanical) are state-issued through DORA. Each municipality fills the gap with its own GC licensing, supervisor certification, and continuing education requirements. Practical impact: a contractor licensed in Denver may not be licensed in Aurora, Boulder, Colorado Springs, or unincorporated counties. Always verify at the city/county where YOUR project is located. The DORA state license database only covers trade licenses (electrical, plumbing, mechanical) — it will return 'no record' for general contractors regardless of how reputable they are.
Three problems. First, work without a Denver-licensed Supervisor on a permittable project is a code violation, and CPD inspectors can stop work and impose 2x permit-fee penalties. Second, your homeowners insurance will likely deny claims tied to unpermitted/unlicensed work — and Colorado's full-disclosure law on home sales requires documenting all work done, so unlicensed work creates resale liability. Third, mechanic's lien rights in Colorado require licensure for protected trades — the contractor has no lien, but you also lose statutory recovery options. Use the Denver contractor search to confirm an active Class III + Supervisor Certificate before any contract.
Denver gets the highest hail-damage payouts in the U.S. The Colorado Roofing Association and most insurers now require Class 4 (UL 2218) impact-resistant roofing for replacement. Many carriers offer 5-30% premium discounts on Class 4 roofs. Denver building code (2018 IRC + Denver amendments) requires ice-and-water shield in valleys, eaves, and around penetrations on roof slopes <4:12. Permits are required for full re-roofs through Denver e-permits. Roofing contractors must be Denver-licensed Class IV roofing contractors, and post-storm scams are a known problem — never hire a 'storm chaser' going door-to-door. CSLB-equivalent verification is the Denver Class IV roofing license search.
Denver's mile-high altitude and dry climate accelerate concrete curing and increase the risk of plastic shrinkage cracking if not managed. Best practice: cover slabs with curing compound or wet burlap immediately, avoid pours in direct afternoon sun May-September, and air-entrain concrete to 6% +/- 1.5% for freeze-thaw durability (required by 2018 IRC for exterior flatwork). Stucco curing also runs faster — use modified mixes and fog-coat between coats. Wood framing dries fast (good for schedule, bad for shrinkage cracking in drywall) — let lumber acclimate 7-14 days before installing finishes. Denver code requires R-49 attic insulation and R-21 wall assemblies; high-altitude HVAC sizing is 5-10% smaller than sea-level equivalents because of lower air density.
Denver Water and the City of Denver promote xeriscape through rebate programs and turf-replacement incentives. As of 2024, all new construction and major renovations in Denver are subject to landscape water-budget rules — the Landscape Code limits Kentucky bluegrass to 60% of irrigated turf area in single-family lots and bans non-functional turf in commercial and HOA common areas. Denver Water Garden In A Box rebates run up to $1,000 for converting turf to native/xeriscape. Rainwater collection is legal in Colorado as of 2016 SB-005 (up to two 55-gallon barrels per single-family home, residential use only). Greywater reuse is permitted under Colorado Reg 86 with a Type 1 simple-system permit through CDPHE.
Ready for a real scope? Talk to Baily — describe the project, drop a photo, and get matched with a Denver-licensed Class III General Contractor the same business day.