Here’s a concise, Colorado-specific guide to finishing a basement — typical costs, code & permit items to watch for, and a practical checklist you can use when planning or talking with contractors.

Quick summary (typical Colorado ranges)

• Typical finished-basement cost in Colorado: roughly $55–$105 per sq ft (scope-dependent). Expect basic finishes at the low end, mid-range upgrades in the middle, and high-end builds (bath, kitchenette, theater, custom millwork) at the high end. (elkstonebasements.com, coloradobuildersgroup.com)
• Expect permit costs and local fees (varies by city/county): small projects often have a few hundred dollars in permit fees; larger projects’ fees scale with valuation. Some jurisdictions publish a flat “basement finish” fee (example: Pikes Peak/Boulder/Denver schedules). (rbdnet.pprbd.org, coloradobuildersgroup.com)

What building code and safety items you must consider (Colorado)

• Egress for sleeping rooms: any basement bedroom must have an approved emergency escape & rescue opening (egress window or door). Minimum net clear opening is typically 5.7 sq ft (5.0 sq ft allowed for grade-floor openings), with minimum clear height 24" and width 20"; sill ≤ 44" above finished floor. Window wells must meet minimum clearances and allow the window to open fully. If you plan bedrooms, plan/install egress up front. (buildingcodegeek.com, daylightegress.com)
• Insulation / energy code: Colorado follows the IRC energy requirements for basement walls — basement-wall R-values are specified by climate zone and must be installed per code (insulation usually installed from the top down to 10 ft below grade or to the floor). Expect to meet the R-values in the local code adoption (this affects whether you use rigid continuous foam, batt+ci, or spray foam). (up.codes)
• Radon: Colorado has widespread elevated radon — the state strongly encourages testing and, if needed, mitigation (sub-slab depressurization is typical; mitigation generally runs roughly $1,000–$2,000 unless complicated). Colorado now requires licensed radon professionals for testing/mitigation. Test (short- or long-term) before finishing so you can plan mitigation into the scope if needed. (cdphe.colorado.gov)

Common add-ons that increase cost (and approximate ranges)

• Egress window cut + well: $2,500–$6,000+ depending on concrete cutting, well, drainage. (Typical national average ~ $2,400–$5,000; Colorado jobs can be toward the top depending on access/drainage.) (thespruce.com, wickhamsworkbench.com)
• Adding a bathroom: $8k–$20k (plumbing, drains, possibly breaking slab).
• Waterproofing / sump pump / drainage tie-in: $1k–$6k+ depending on whether interior perimeter drain or exterior excavation is required.
• Radon mitigation system: typically $1k–$2k in Colorado (can be higher if layout is difficult). (cdphe.colorado.gov)

Practical order of operations (recommended)

1. Test the space (radon short-term test, look for moisture, check for structural issues). If radon > action level, plan mitigation before finish. (cdphe.colorado.gov)
2. Get local code/permit check — contact your city/county building department or use their online “start a project” guidance. Permits are typically required for basement finishes (framing, electrical, plumbing, HVAC). Fees vary by jurisdiction. (pprbd.org, rbdnet.pprbd.org)
3. Solve water/drainage first (grade, gutters, foundation cracks, interior perimeter drain/sump) — any finished basement must be dry.
4. Install radon mitigation (if required) and waterproofing.
5. Rough-in: framing, insulation (to code), plumbing, electrical, HVAC adjustments (add returns/heat runs or mini-split if needed).
6. Inspections for rough work (framing/plumbing/electrical).
7. Drywall, finishes, trim, flooring, fixtures. Final inspections and certificate of occupancy (where required).

Checklist for hiring contractors / getting bids

• Get at least 3 written bids with the same scope.
• Ask each contractor for license, insurance, references, and a project timeline. (For radon work, require a Colorado-licensed radon professional.) (dora.colorado.gov)
• Confirm who handles permits/inspections (owner vs. contractor). Many local codes require licensed contractors to obtain permits. (pprbd.org)
• Ask about waterproofing approach (interior vs exterior), where they’ll run plumbing/drains, egress/window options, and how they’ll handle HVAC and dehumidification.
• Include a 10–20% contingency in your budget for surprises (hidden moisture, structural issues, slab work).

Timeline (typical)

• Small cosmetic finishes: 2–4 weeks.
• Full basement finish (bathroom + bedrooms + living space): often 8–12+ weeks depending on scope, inspections, and subcontractor scheduling.

Local next steps (quick practical actions)

1. Measure basement square footage and write down desired rooms/features (bathroom? bedroom? kitchenette?).
2. Order a radon test kit (your county/state often provides free/discounted kits — CDPHE has resources). Test before you finish. (cdphe.colorado.gov)
3. Call your city/county building department (or check the online permit/fee schedule) to confirm required permits and fee estimates for your jurisdiction. Example fee schedules and “basement finish” permit categories vary — check the local fee schedule. (rbdnet.pprbd.org, coloradobuildersgroup.com)
4. Get 2–3 contractor bids that include permit handling, and compare scope line-by-line.

If you’d like, I can:

• Look up the building department and permit fee page for a specific Colorado city or county (Denver, Boulder, Colorado Springs, Fort Collins, etc.).
• Find licensed radon mitigation companies in your county or show free/low-cost radon test kit links from CDPHE.

Which city or county in Colorado is your house in? If you give me that, I’ll pull up the local permit page, the permit-fee estimate, and any local amendments (egress or energy code changes) that might affect your project.