The office that governs your street address issues your basement finish permit. Inside Denver that's Community Planning and Development (CPD).1 Aurora, Arvada, Lakewood and Littleton each run their own building department. Highlands Ranch homes sit in unincorporated Douglas County, so they go to the county Building Division in Castle Rock.2 What changes from office to office is the drawing set, the egress rule and how the fee is figured.
TL;DR
- Your address picks the office: Denver CPD, the Aurora Permit Center, Arvada Building Services, the Lakewood Building Division, the Littleton Permit Center or the Douglas County Building Division.
- Every office checked here treats a basement finish with new walls or wiring as permit work. Denver's exempt list covers small jobs like painting, flooring and one sheet of drywall.
- Aurora charges one flat fee for a basement finish. The other five price the permit from the job's valuation and add plan review, so the same job costs different amounts in different towns.
- Plan on an egress window or door even without a bedroom. Douglas County, Lakewood, Littleton and the Aurora guide all ask for one in the basement.
- Radon isn't a submittal item on any captured basement page. Test anyway and settle any mitigation piping before the drywall goes up.
Which office issues a basement finish permit in metro Denver?
The building department for the city or county that governs your address issues it. Denver residents apply to CPD.1 Aurora, Arvada, Lakewood and Littleton residents apply to their own city. Highlands Ranch and other unincorporated Douglas County homes apply to the county.2 A mailing address can mislead, so check the city limits first.
Littleton and Arvada both link an address lookup for exactly this reason.34 Every entry below comes from the office's own pages, captured in September 2026, and gaps are marked for you to confirm. Local adoption and amendments vary, so check the current rules with the office before your contractor submits.
| Jurisdiction | Permit office and how to apply | Drawings asked for | Egress | Radon | Inspections | Fee basis |
|---|---|---|---|---|---|---|
| Denver | Community Planning and Development. Apply online in e-permits and pick "Building Log."1 | Site plan to scale with a north arrow, floor plan labeling existing and proposed rooms, building elevations and energy code compliance.1 | New egress windows need a permit.1 The captured pages don't state a basement egress rule. Confirm with CPD. | Not stated on the captured pages. Confirm with CPD. | The inspection card lists rough and final plumbing, electrical and mechanical, plus frame, insulation, drywall and final.5 | Valuation table, plus plan review at 50% of the permit fee on jobs over $2,000.6 |
| Aurora | City of Aurora Permit Center, 15151 E. Alameda Parkway, Suite 2400. Apply online at Aurora4Biz.org.7 | Scaled floor plan of the whole basement with room uses, outlets, smoke and CO alarms, lighting, fans, plumbing, furnace, water heater, windows, egress wells, structural changes and insulation values.8 | The guide Aurora posts says all basements and sleeping rooms need an escape window or exterior door.8 | A radon system needs no permit unless new electrical is added for the fan.9 | Framing, mechanical, plumbing and electrical. Every inspection has a rough and a final.9 | 2026 flat fee of $536 for a basement finish. Use tax is still calculated.7 |
| Arvada | Building Services at City Hall, 8101 Ralston Road. Apply at arvadapermits.org.4 | Dimensioned floor plan in blue or black ink on white with room uses, electrical, alarms, plumbing, furnace, water heater, windows and wells. Engineer's stamp for structural changes or new egress windows.4 | The basement permit covers egress windows. New egress windows need an engineer's letter.4 | Not stated on the captured pages. Confirm with Building Services. | A list of 13 common inspections, from underground plumbing to final structural.4 | Valuation (the higher of your contract or the city's table) on Table 18-1, plus plan review and use tax.10 |
| Lakewood | Building Division. Apply through eTRAKiT.11 | Separate existing and proposed floor plans, new electrical and plumbing, a floor to ceiling section showing floating walls and finished ceiling heights under beams and ducts.11 | An egress window in each bedroom. A basement with no bedroom needs at least one egress window or door.11 | The division lists a "Radon Control Methods" handout.12 Its content wasn't captured. Confirm with the Building Division. | Includes underground and rough plumbing, shower pan, rough mechanical, gas piping, rough electrical, framing, insulation, drywall and finals.13 | Valuation table, plus plan review at 65% of the permit fee. The posted schedule dates from 2021.14 |
| Littleton | Permit Center at Littleton Center, 2255 W. Berry Avenue. Submit electronically through eTRAKiT.15 | Existing and proposed floor plans with north arrow, framing members, room uses, ceiling heights, doors, windows, stairs and beam and duct heights. Electrical, plumbing and mechanical layouts.15 | Basements and every sleeping room need at least one egress window or door.15 | Not stated on the captured pages. Confirm with the Permit Center. | The captured pages don't list a basement inspection sequence. Confirm with the Permit Center. | Valuation table, plus a use tax deposit, Arapahoe County open space tax and plan review at 65%.16 |
| Douglas County (Highlands Ranch) | Douglas County Building Division, 100 Third Street, Castle Rock. Over the counter plan review weekdays 8 a.m. to noon.2 | One set of ¼ inch scale plans in blue or black ink (two for over the counter review) showing rooms, fixtures, windows, doors, egress wells, furnace, water heater, stairs, unfinished areas and alarms.2 | Required in every finished basement no matter when the house was built. With bedrooms, each bedroom needs one.17 | Not in the captured guide. Confirm with the Building Division. | Underground plumbing, electrical slab, rough electric, rough frame, gas line, insulation, shower pan, drywall, final electric and final building.17 | Valuation from the finished square footage, run through 1997 UBC Table 1-A, plus plan review at 65%.218 |
What does each office ask for beyond the table?
Each office adds its own rules on who can pull the permit, how long review takes and which code edition applies. These details decide whether you can do part of the work yourself and how early your contractor needs to submit. Find your city or county below, then confirm the current version with that office.
Denver
Denver issues basement permits through e-permits.1 Electrical, plumbing and mechanical work usually goes on separate trade permits, most issued online as quick permits.1 A homeowner can pull the permit only for a single-family home they own and live in. They must pass an exam before doing electrical, plumbing or mechanical work and stay in the home a year after the work is done.19 Denver's current code is the 2025 Denver Building Code, which builds on the 2024 I-codes.20 Two edge cases matter. Interior remodels over 2,500 square feet of modified floor area fall under the city's recycling ordinance.1 Exterior work in a historic district, like a new egress window, needs a certificate of appropriateness.1
Aurora
Aurora enforces the 2021 International Residential Code.21 Its basement guide asks you to consult the building department if a finished ceiling will be under 7 feet.8 It also asks for walls on the slab to allow at least 1-1/2 inches of floor movement where floors heave.8 Homeowners can pull permits for work on their primary home, and any contractor you hire must hold an Aurora license.9 A permit expires if work doesn't start within six months or finish within one year.9
Arvada
Arvada issues one basement permit that includes the mechanical, plumbing, electrical and egress window work.4 An owner who lives in the home and does the work needs no license. A hired contractor needs a Class B or Class C license, and subcontractors sign on to the same permit.4 Plan review takes 1 to 2 days, depending on the plans and the workload.4 Hand-drawn plans can be dropped off at City Hall for staff to scan.4 Arvada adopted the 2024 IRC on March 24, 2026, and its implementation page decides which code cycle your project falls under.22 After the final inspection the permit shows as finaled, with no certificate of occupancy needed.4
Lakewood
Lakewood wants the permit before any work starts.11 Homeowners may pull permits and do the work on their own single-family home, duplex or townhouse, though not in a condo.11 Every wall built on the concrete slab must float, with at least 1½ inches of float.11 Swelling soil is common in Colorado and can badly damage houses.23 A floating wall leaves a gap above the plate fastened to the slab, so a heaving slab can't shove the wall up into the floor framing. Finished rooms need a 7 foot ceiling, and perimeter walls need at least R-15 continuous or R-19 cavity insulation.11 Lakewood enforces the 2021 IRC with local amendments.12 Inspections requested before 7:30 a.m. can usually happen the same business day.13
Littleton
Littleton takes submittals electronically only, and the applicable code editions must be noted on the plans.15 Plans marked "Preliminary" or "Not for Construction" aren't accepted.15 If the heating system or ductwork changes, the plans need Manual J, S and D calculations.15 Any change to the foundation needs a structural engineer's stamped drawing, and that engineer must inspect the work before final approval.15 The city enforces the 2024 IRC.24 The Permit Center is closed on Fridays.15
Douglas County (Highlands Ranch)
The county says a basement finish needs a permit once any walls go up or electricity is added.2 A complete application normally takes 7 to 10 business days.2 Homes with fire sprinklers need written approval from the fire district for the basement sprinkler design.2 Homes on septic need a Douglas County Health Department letter before adding a bedroom.2 If a contractor does the work, the contractor pulls the permit.17 A permit expires after 180 days without inspections.2 The county adopted the 2024 IRC effective July 1, 2026.25
How much does a basement finish permit cost?
Aurora charges a flat $536 for a basement finish in 2026.7 The other five offices price the permit from the job's valuation, then add plan review. Arvada and Littleton also list use tax on their fee pages, and Littleton adds a county open space tax.1016 On the same $40,000 job, that works out to about $510 in Denver and about $1,820 in Littleton.616
That $40,000 figure is only an illustration. It sits inside the $30,000 to $90,000 range one local builder published for finishing a basement in metro Denver (checked September 2026). The office sets the real valuation, and several won't accept a number below their own table. Arvada uses the higher of your contract or its valuation table, and that table has its own line for a basement finish at $31.50 a square foot.10 Lakewood also uses the higher of your figure or its calculated one.14 Douglas County bases the valuation on the square footage you finish.2
Here's the arithmetic on each office's published table for a $40,000 valuation:
| Office | Building permit fee | Plan review | Other charges on the fee page | Our total |
|---|---|---|---|---|
| Denver | $340.00 ($220 plus $8 for each $1,000 over $25,000)6 | $170.00 (50%)6 | Optional $25 youth construction contribution6 | $510.00 |
| Aurora | $536 flat7 | Not listed | City use and county taxes still calculated7 | $536 plus taxes |
| Arvada | $553.25 ($401.75 plus $10.10 for each $1,000 over $25,000)10 | 65% of the permit fee, or $40 for modifications to existing single-family homes10 | Use tax10 | Confirm with Arvada |
| Lakewood | $533.15 ($395.15 plus $9.20 for each $1,000 over $25,000)14 | $346.55 (65%)14 | 2021 schedule. Fees change periodically.14 | $879.70 |
| Littleton | $597.02 ($430.37 plus $11.11 for each $1,000 over $25,000)16 | $388.06 (65%)16 | Use tax deposit $787.60, open space tax $50.0016 | $1,822.68 |
| Douglas County | $542.75 ($391.25 plus $10.10 for each $1,000 over $25,000)18 | $352.79 (65%)18 | One fee covers building, electrical, mechanical and plumbing. Schedule dated 2018.18 | $895.54 |
Arvada's schedule lists both plan review rates without saying which one a basement finish gets, so ask. Denver can require separate trade permits, and it adds a 2.5% service fee on eligible card payments.16 Reinspections cost extra too. Denver charges $100 an hour, Arvada $125, Littleton and Lakewood $80 an hour, and Douglas County $47 an hour.610161418 The permit is a small line next to the build itself, so see what finishing costs in Denver before you set a budget.
Can you finish a basement with no egress window?
In most of this metro, plan on one. The 2021 IRC, section R310.7, says an existing basement being altered needs a new escape opening only if you add a bedroom.26 Douglas County, Lakewood and Littleton ask for one in the basement anyway, and every bedroom needs its own.171115 Local adoption and amendments vary.
The local rules go further than the model code. Douglas County requires emergency egress in every finished basement no matter when the house was built.17 Lakewood requires at least one egress window or door in a basement without bedrooms.11 Littleton requires one in basements and every sleeping room.15 The guide Aurora posts says the same for all basements.8
An egress window is an emergency escape and rescue opening, a window or door big enough to climb out of. The 2021 IRC sets the net clear opening at 5.7 square feet or more.26 Littleton's checklist spells out the rest: at least 24 inches of clear height, 20 inches of clear width and a sill no more than 44 inches above the floor.15 A window below grade needs a well with at least 9 square feet of clear area and 36 inches in each direction. Wells deeper than 44 inches need a fixed ladder or steps.15
Cutting a new opening in a foundation wall is structural work. Arvada, Lakewood, Littleton and Douglas County all want an engineer's design or stamp for it.4111517 Douglas County will accept a pre-existing window well with a 24 inch projection if everything else meets the rule.17 Aurora prices an egress window as its own $99 flat permit.7 For how egress fits the rest of a Front Range build, read our guide to finishing a basement in Colorado.
Where does radon fit in the permit?
Mostly outside it. None of the six offices' captured basement pages lists a radon test as a submittal item. Colorado's health department calls radon the leading cause of lung cancer among non-smokers in the United States.27 Test before you finish, and if the result calls for a radon mitigation system, use a licensed radon professional.
The state health department puts radon at about 500 lung cancer deaths a year in Colorado. It comes from uranium breaking down in the soil under a house.27 A few permit pages touch radon at the edges. Aurora's chart says a radon system needs no permit unless new electrical is added for the fan.9 Arvada's fee schedule includes a registration for state-licensed radon mitigation professionals.10 Lakewood's Building Division posts a radon control handout.12 The practical point is timing. A mitigation pipe and fan circuit are easy to route through open framing and hard to add after drywall.
Can I finish my basement without a permit?
Not once the job adds walls, wiring or plumbing. Lakewood says permits are required for basement finish work before you start.11 Aurora's chart marks a basement finish as always needing a permit.9 Denver's exempt list covers only small jobs, like painting, flooring and patching one sheet of drywall.19
Denver also notes that a wastewater, zoning or fire permit may be required even when a building permit isn't.19 Skipping the permit tends to cost more later. Aurora warns that a buyer's home inspection can turn up unpermitted work, stall a sale and force you to redo it with a permit.9 It also says insurers may not cover work done without permits and inspections.9 In Littleton, the investigation fee for work without a permit is double the permit fee.16
What should you ask your contractor about the permit?
Ask who pulls the permit, which office it goes to, what the drawings will show and which inspections they'll book. The answers tell you whether the quote includes permit work or leaves it to you. A good quote names the office and lists the permit fee as its own line.
Questions worth asking before you sign:
- Will you pull the permit in your company's name? Denver's own hiring tips warn against contractors who want the permit in the homeowner's name, because the permit holder is legally responsible for the work.19
- Are you licensed or registered with my city? Aurora, Arvada and Lakewood each require hired contractors to hold local credentials.9411
- Does the plan set show egress, floating walls, ceiling heights and alarms?
- Which inspections will you book, and will you hold drywall until rough work passes? Denver's inspection card says rough work in walls, ceilings and floors shall not be covered until it's inspected and approved.5
- Does the quote include an engineer's stamp if an egress window needs a new opening?
- When is final payment due? Denver advises holding final payment until building inspections are approved.19
When you're ready, get a written quote for finishing your basement in Denver. Basement Remodeling Co. sends your request to one vetted, licensed basement contractor, and your contractor pulls the permit and books the inspections. Suburban homeowners can start from the Aurora basement remodeling page, the Arvada page or the Lakewood page. Anywhere else, find a basement contractor by ZIP code or browse the Denver metro hub.