Skip to main content
PermitBase

Residential Addition / Remodel / Basement Finish Permit in Castle Rock, Colorado

Required for additions, basement finishes, and structural alterations to existing one- and two-family dwellings in Castle Rock. Reviewed under the 2024 IRC as locally amended. Basement finishes, decks, patio covers, sunrooms, carports, and detached garages follow a faster review track than full additions per the Town's own published timeline table.

Verified 2026-07-05 · Source

When you need this permit

  • Building permits required for additions, remodels, interior improvements, basement finishes, decks, patios, awnings, pools, and spas
  • Permits required for retaining walls over 4 feet high (including the footing/foundation) and for new mechanical equipment
  • Plans must comply with the 2024 IRC as locally amended, including Castle Rock's amended structural design criteria (115 mph wind, Seismic Category B, 36-inch frost depth, tiered snow load)
  • Deck construction must meet the Town's amended Table R507.7 maximum joist spacing table for decking material/thickness
  • Contractor registration required; homeowner self-permit option available only for the applicant's own owner-occupied primary residence Owner-builderContractor

Required documents

Check off what you have — your progress is saved on this device.

Not ready yet — 0 of 3 required documents checked.

This checker covers one permit. A full project usually triggers several — our paid checklist will assemble all of them, from $29 →

Fee schedule

Building Permit Fee (valuation-based, same tiers as new construction)Town of Castle Rock Development Services Fee Schedule, effective July 1, 2026
$23.50 minimum, scaling to $5,608.75 + $3.65/$1,000 over $1,000,000
Plan Review Fee
65% of the Building Permit Fee
Miscellaneous Permits and Fees (default, unless separately scheduled)
$75.00

Review timeline

Plan reviewCastle Rock’s published plan-review target
5–5 business days

How long did your Residential Addition / Remodel / Basement Finish Permit permit actually take in Castle Rock?

Anonymous — one question, no email. Answers are combined and only shown once at least 5 people have reported.

Inspection process

  1. 1

    Foundation (if applicable)

    For additions or garages with new footings — 36-inch minimum frost depth

  2. 2

    Framing

    Structural framing and connection to existing structure

  3. 3

    MEP Rough-In

    Mechanical, electrical, plumbing rough-in before walls closed

  4. 4

    Final

    All work complete per approved plans

See the full Castle Rock inspection guide — scheduling & re-inspection fees →

Tips

  • Basement finishes, decks, patio covers, sunrooms, carports, detached garages, and pools/spas all share the Town's fastest published review track (5 days), versus custom homes/master plans (21 days) or larger tenant improvements.
  • A permit is required for retaining walls over 4 feet high (including the footing), and for fences over 6 feet — verify your wall/fence height against these Town-specific thresholds before assuming exempt work.
  • Decks: the Town has its own amended maximum joist-spacing table (Table R507.7) for decking material and thickness — confirm your decking spec against the Castle Rock-specific version, not just the base IRC table.

Frequently asked questions

Yes, if it exceeds 4 feet in height, including the footing/foundation. Source: Town of Castle Rock Development Procedures Manual, Chapter X - Permits.

In Castle Rock, the published Building Permit Fee (valuation-based, same tiers as new construction) is: $23.50 minimum, scaling to $5,608.75 + $3.65/$1,000 over $1,000,000. Additional published fees: Plan Review Fee — 65% of the Building Permit Fee; Miscellaneous Permits and Fees (default, unless separately scheduled) — $75.00. These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Castle Rock's published plan-review target for a residential addition / remodel / basement finish permit is 5–5 business days.

You'll need: Plan Review and Construction Permit Application (eTRAKiT); Residential Addition Checklist; Site Plan / Construction Drawings. Depending on your project, Castle Rock may also ask for: Basement Finish Checklist and Building Guide. See the required-documents checklist on this page for details on each.

Castle Rock requires 4 inspection(s) for a residential addition / remodel / basement finish permit, in order: Foundation (if applicable), Framing, MEP Rough-In, Final. Schedule each through Town of Castle Rock Development Services, Building Division (720-733-3527).

Apply through Town of Castle Rock Development Services, Building Division at 100 N. Wilcox St., Castle Rock, CO 80104. Phone: 720-733-3527, email: buildingcounter@crgov.com. Office hours: Development Services Building Counter (Town Hall): Monday-Friday, 8 a.m. to 5 p.m. Inspection scheduling line: 303-660-1341.. Official information: https://www.crgov.com/1887/Building.

Castle Rock, Colorado has adopted: The Town of Castle Rock is a home-rule municipality that runs its OWN Building Division — it is a separate prequalified building department from Douglas County (confirmed via the Colorado Division of Fire Prevention and Control's Prequalified Building Departments list, which shows both 'Douglas County' and 'Town of Castle Rock' as distinct entries; Joseph Montoya is the Town of Castle Rock's listed prequalified contact, jmontoya@crgov.com, 720-733-2225). Source: Colorado DFPC Prequalified Building Departments list, https://dfpc.colorado.gov/sites/dfpc/files/Current%20Prequalified%20Building%20Departments.pdf; 2024 International Building Code (IBC), as amended by Ordinance No. 2026-017, adopted by Town Council June 2, 2026, effective June 30, 2026 (amending Castle Rock Municipal Code Title 15, Chapter 15.04); 2024 International Residential Code (IRC) for One- and Two-Family Dwellings, as amended by Ordinance No. 2026-017 (Castle Rock Municipal Code Chapter 15.06); 2024 International Plumbing Code (IPC); 2024 International Mechanical Code (IMC); 2024 International Fuel Gas Code (IFGC); 2024 International Fire Code (IFC), enforced by Castle Rock Fire and Rescue Department; 2024 International Existing Building Code (IEBC); 2024 International Swimming Pool and Spa Code (ISPSC); 2021 International Energy Conservation Code (IECC) — Castle Rock has adopted the 2024 editions of most I-Codes but retains the 2021 IECC rather than a newer edition; 2023 Colorado Model Electric-Ready and Solar-Ready Code, adopted by reference as new Castle Rock Municipal Code Chapter 15.15 via Ordinance No. 2026-017; applies to all new residential and commercial buildings and to additions/substantial remodels requiring a building permit; 2026 National Electrical Code (NEC); 2017 ICC A117.1 Accessible and Usable Buildings and Facilities (Ordinance No. 2026-017 adds a new Section 1102, Compliance, specifying the 2017 edition); 1997 Uniform Code for the Abatement of Dangerous Buildings; ASME A17.1-2022 (Safety Code for Elevators and Escalators), ASME A18.1-2020 (Platform Lifts and Stairway Chairlifts), ASME A17.3-2023 (Existing Elevators and Escalators); 2021 Automated People Mover Standards (ASCE 21, Parts 1-4); 2025 Colorado Wildfire Resiliency Code, effective July 1, 2026 (Castle Rock Municipal Code Chapter 15.20, per Ordinance No. 2026-017 amendments); Source for the full current adopted-code list and effective dates: Town of Castle Rock Adopted Building Codes page, https://www.crgov.com/2178/Adopted-Building-Codes, and Ordinance No. 2026-017 (full amendment text), https://www.crgov.com/ArchiveCenter/ViewFile/Item/2870. Local amendments apply — see the Castle Rock overview page for the full list.

Sources & verification

Verified against official sources. Last reviewed 2026-07-05.

Fees, timelines, and adopted codes are researched from each jurisdiction's published records — see how we verify. Requirements change and vary by project, so always confirm the current details with the Castle Rock building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.

Other permits in Castle Rock

Residential Building Permit (New Construction)Electrical PermitPlumbing PermitMechanical / HVAC PermitRoofing Permit (Re-Roof)Demolition PermitSolar Photovoltaic (PV) PermitFence and Retaining Wall PermitEV Charger / EVSE Permit

Residential Addition / Remodel / Basement Finish Permit in other cities

Akron, ColoradoArvada, ColoradoAspen, ColoradoAult, ColoradoAurora, ColoradoAvon, ColoradoBasalt, ColoradoBennett, Colorado

Compare residential addition / remodel / basement finish permit fees across Colorado →

Look up this fee in a different city →

Embed this data card →

Now live

Build your Castle Rock project checklist

Describe your project once and get every permit, document, and fee it triggers in Castle Rock — in one checklist. Sign up and pay once to generate it, or go unlimited with Pro.

Get started →