Residential Addition / Alteration-Remodel Permit in Aspen, Colorado

Aspen requires a residential addition / alteration-remodel permit for: Reviewed under the 2021 IBC as locally amended; Classified as a New Minor Permit or New Major Permit depending on whether the addition/remodel changes floor area, height, net livable, or net leasable area (Major) versus other alterations (Minor); The Building Permit Application Checklist distinguishes required submittals by column: New Construction, Addition, Alteration/Remodel, and Alteration (Interior only) each have different required document sets; Asbestos test required if affecting more than 160 sq ft of potentially asbestos-containing materials when altering interior walls, per the EPIC Permit Policy's interior-wall-change requirements (also applicable outside EPIC scope); A Licensed Structural Engineer's stamped plans or stamped letter of structural engagement required for any interior wall changes; If alteration area exceeds 50% of the building footprint, Engineering Development requires a major grading & drainage report, stamped civil plan, current survey, and a soils report. If your project isn't listed, confirm with City of Aspen Community Development Department, Building Division at 970-920-5000 before starting work.

In Aspen, the published Building Permit Fee (valuation-based) is: Computed via the City's Building Permit Fee Estimator (Excel) referencing the current Municipal Code Fee Ordinance (Title 2). These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Aspen's published plan-review target for a residential addition / alteration-remodel permit is 56–70 business days.

You'll need: Building Permit Application Checklist for Singlefamily, Duplex, and Townhouse Projects (2021 IBC). Depending on your project, Aspen may also ask for: Stamped Structural Engineer Letter or Plans. See the required-documents checklist on this page for details on each.

Aspen requires 4 inspection(s) for a residential addition / alteration-remodel permit, in order: Foundation (additions with new footings only), Rough Frame, Rough Electrical / Plumbing / Mechanical, Final Inspection. Schedule each through City of Aspen Community Development Department, Building Division (970-920-5000).

Apply through City of Aspen Community Development Department, Building Division at 427 Rio Grande Place, Aspen, CO 81611. Phone: 970-920-5000, email: buildingsupport@aspen.gov. Office hours: City of Aspen main line 970-920-5000. Building Support (permit requirement inquiries, pre-submittal questions): buildingsupport@aspen.gov, Monday-Friday 9:00am-5:00pm. Builder of the Day (building code/regulations questions): builderoftheday@aspen.gov, 970-429-2735, Monday-Friday 8:30am-4:30pm. Planner of the Day (zoning, floor area, net leasable, signage, mountain view plane, exterior design): planneroftheday@aspen.gov, 970-429-2764, walk-in hours Monday-Friday 9:00am-12:00pm. Historic Preservation: HP@aspen.gov, 970-429-2758. Construction hours: Monday-Friday 7:30am-5:30pm, Saturday 9:00am-5:00pm, no construction on Sundays.. Official information: https://aspen.gov/179/Building.

Aspen, Colorado has adopted: 2021 International Building Code (IBC) — adopted by Ordinance #1, 2023 (January 24, 2023), effective for permits submitted March 31, 2023 and later; the IRC has NOT been adopted by the City of Aspen and is not applied — single-family, duplex, and townhouse projects are reviewed under the 2021 IBC as locally amended, per the City's own 'Building Permit Application Checklist for Singlefamily, Duplex, and Townhouse Projects (2021 IBC)'; 2021 International Existing Building Code (IEBC); 2021 International Mechanical Code (IMC); 2021 International Fuel Gas Code (IFGC); 2021 International Plumbing Code (IPC); 2021 International Fire Code (IFC); 2021 International Swimming Pool and Spa Code (ISPSC); 2021 Aspen Energy Code (local amendment/supplement to the IECC); 2023 National Electrical Code (NEC), effective August 1, 2023; 2024 Colorado Wildfire Resiliency Code with local amendments — adopted by Ordinance 6, 2026 (March 25, 2026), effective April 23, 2026; referenced directly in the current Fence Permit Application Checklist (fences within 8 feet of a structure must be noncombustible/ignition-resistant; hedges within 5 feet must use ignition-resistant vegetation); Prior code cycle: 2015-edition IBC/IEBC/IMC/IFGC/IPC/IFC applied to permits submitted between February 2017 and March 2023, with local amendments in Ordinance 40, 2016 (superseded, listed for reference only); Local amendments to all adopted codes are codified in Title 8 (Building and Building Regulations) of the Aspen Municipal Code; Municode's Aspen library is a JavaScript-rendered application that could not be scraped directly in this or the prior session (confirmed again 2026-07-23: raw curl returns only the Angular SPA shell, and the shared browser environment used for the re-chase attempt this session was too unstable to reliably render deep-linked Title pages). However, the City's own 'Currently Adopted Building & Energy Codes' page (aspen.gov/197) directly publishes a 'Climate & Geographical Design Criteria' table (2026-07-23, live-confirmed): Ground snow load 100 psf; Wind Speed/Exposure Category 89 mph / B; Seismic Design Category C; Weathering Severe; Frost line depth 36 inches; Termite None to slight; Decay None to slight; Winter design temp -15°F; Summer design temp 82°F; Ice shield underlayment required Yes; Air Freezing Index 2000; Mean annual temperature 40°F. This resolves the design-criteria gap without needing Title 8/Municode.. Local amendments apply — see the Aspen overview page for the full list.

It depends on whether it changes floor area, height, net livable, or net leasable area. If it does not, it is typically classified as a New Minor Permit (published 8-10 week Round 1 timeline); if it does, it is a New Major Permit (16-18 weeks).