Residential Addition / Remodel Permit in Westminster, Colorado
Required for room additions, basement finishes, remodels, and structural alterations to existing one- and two-family dwellings in Westminster. Uses the same valuation-based fee schedule as new residential construction.
Verified 2026-06-30 · Source
When you need this permit
- Room additions, attached/detached garages, and accessory buildings larger than 120 sq ft require a permit
- Basement finishes and remodels involving modifications to electrical, plumbing, mechanical, and/or structural systems require a permit
- Installation of additional windows or doors, or a change in window/door size, requires a permit
- Electric-to-gas conversions require a permit
- Plans must show scope, dimensions, structural details, and connection to the existing structure
- Structural work must meet the City's Design Criteria for Structures (30 psf snow, Seismic Design Category B, City Map Wind Zone speed)
Required documents
- Req
Building Permit Application (eTRAKiT)
Online application; select the applicable remodel/addition permit type
- Req
Site Plan
Property lines, existing structures, proposed addition footprint, setbacks
- Req
Construction Drawings
Plans showing the addition/remodel scope, including structural details if structural work is involved
- Req
Residential Additions Plan Submittal Requirements
City of Westminster's current checklist for addition and remodel submittals
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Building Permit Fee — valuation-based (same tiers as new construction) | Varies by valuation — see Residential Building Permit fee tiers ($19.50 minimum, up to $4,659.20 + $2.65/$1,000 over $1M) | City of Westminster Building Division Fee Schedule, effective January 1, 2026 |
| Plan Review Fee | 65% of the Building Permit Fee | — |
| Permit Trade Fees (mechanical, plumbing, electric) | An additional 15% of the Building Permit Fee, plus 15% of the Plan Review Fee, for each trade involved | — |
| Estimated Use Tax | 4.25% of 50% of Total Valuation | — |
Review timeline
~1–1 business days
Typical estimate — confirm current times with the Westminster building department
Inspection process
- 1
Foundation (if new footings)
Before concrete pour — 36-inch frost depth minimum
- 2
Framing
After framing complete, before insulation or wall cover
- 3
MEP Rough-In
Electrical, plumbing, mechanical rough-in before walls closed
- 4
Final
All work complete per approved plans
Tips
- Additions and remodels use the same valuation-based fee table (and 65% plan review rate) as new residential construction — there is no separate flat-rate schedule.
- Structural additions must meet Westminster's Design Criteria for Structures (30 psf snow, Seismic Design Category B, City Map Wind Zone-based wind speed) — confirm your parcel's wind zone (1, 2, or 3) before finalizing structural plans.
- Replacing plumbing/light fixtures in place does NOT require a permit, but relocating them does.
Frequently asked questions
- Do I need a permit for a basement finish in Westminster?
- Yes, if the basement finish involves framing, electrical, plumbing, or mechanical work. A building permit is required and reviewed against the 2021 IRC with Westminster amendments.
Sources & verification
Verified against official sources. Last reviewed 2026-06-30.
- City of Westminster — Department of Community Development, Building Division — official building department
- City of Westminster — Apply for a Permit / Project
- Residential Building Permit Requirements (updated 08-22-2024) (PDF)
- Residential Additions Plan Submittal Requirements (PDF)
- Building Division Fee Schedule, effective January 1, 2026 (PDF)
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 Westminster building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.
Other permits in Westminster
Get the AI compliance checklist
Upload your project scope, get a jurisdiction-specific checklist of everything you need. Coming soon.
We only use your email to send permit updates. No spam, unsubscribe anytime. Privacy.