Westminster Roofing Codes: Permits, Inspections, and Requirements
Adopted building and energy codes, permit rules, and roofing requirements for Westminster, Adams and Jefferson Counties. Rows below reflect our reading of the jurisdiction's own published sources, linked at the bottom of the page.
Building department
303-658-2075Inspection line
303-658-2075Permit line
303-658-2075Official department
Live code pageWestminster roofing code requirements
- What this jurisdiction requires
- 2021 IBC and 2021 IRC
- What this jurisdiction requires
- 2021 IECC
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Class A
- What this jurisdiction requires
- Required. Westminster is a special wind region, so all asphalt shingles get high wind nailing per manufacturer specifications
- What this jurisdiction requires
- Not required for asphalt shingle installation. Required for batten type roofing such as tile and coated metal
- What this jurisdiction requires
- One layer
- What this jurisdiction requires
- Required. Asphalt shingles must be fastened to a solidly sheathed deck per R905.2.1
- What this jurisdiction requires
- Required
- What this jurisdiction requires
- Required
- What this jurisdiction requires
- Ice barrier required at eaves per the IRC
- What this jurisdiction requires
- Two layers of underlayment
- What this jurisdiction requires
- One layer of underlayment
- What this jurisdiction requires
- Required where the roof meets a wall
- What this jurisdiction requires
- Required, installed to manufacturer specifications
- What this jurisdiction requires
- Required on new construction under the 2021 IECC
- What this jurisdiction requires
- Required per IRC attic ventilation provisions
| Requirement | What this jurisdiction requires |
|---|---|
| Current building code | 2021 IBC and 2021 IRC |
| Current energy code | 2021 IECC |
| Building permit required | Yes |
| Roof system fire rating (residential) | Class A |
| Requires wind nailing | Required. Westminster is a special wind region, so all asphalt shingles get high wind nailing per manufacturer specifications |
| Requires midroof (in progress) inspection | Not required for asphalt shingle installation. Required for batten type roofing such as tile and coated metal |
| Maximum layers of asphalt shingles permitted | One layer |
| Requires solid sheeting over spaced decking | Required. Asphalt shingles must be fastened to a solidly sheathed deck per R905.2.1 |
| Requires drip edge | Required |
| Requires rake / gable metal edging | Required |
| Self adhering underlayment (ice and water shield) | Ice barrier required at eaves per the IRC |
| Underlayment required 2:12 up to 4:12 | Two layers of underlayment |
| Underlayment required 4:12 and above | One layer of underlayment |
| Kick-out required on step flashing | Required where the roof meets a wall |
| Requires ridge cap | Required, installed to manufacturer specifications |
| Blower door test when increasing ventilation to code | Required on new construction under the 2021 IECC |
| Requires soffit / eave vents | Required per IRC attic ventilation provisions |
Last checked September 2, 2026. This reflects published sources at that date, not an official ruling. Code adoptions change, so confirm with the Westminster building department before you pull a permit.
What Westminster requires, in plain language
Westminster builds to the 2021 IBC and 2021 IRC. That edition, not the newest code published nationally, is the rulebook an inspector in Adams and Jefferson Counties holds your roof to. Energy work on the same permit follows the 2021 IECC.
Layer limit in Westminster: One layer. This is the line item that moves a bid the most. If your existing roof is already at the limit, the deck gets stripped before new material goes down, and the labor plus dump fees belong in the written price.
Wind is what Westminster tests shingles against. Wind nailing: Required. Westminster is a special wind region, so all asphalt shingles get high wind nailing per manufacturer specifications.
Underlayment and edge metal are where roofs fail inspection. Ice and water shield: Ice barrier required at eaves per the IRC. On 2:12 to 4:12 slopes: Two layers of underlayment. On 4:12 and steeper: One layer of underlayment. Drip edge: Required.
The Westminster Building Division applies the 2021 IBC, IFC, IRC, IPC, IMC, IFGC and IECC per its published plan review and submittal guidelines.
Sources
These links go straight to the jurisdiction, so you always have the real-time source. Adoptions and amendments change on their schedule, not ours. Always confirm before permitting.
Last checked September 2, 2026. This is our best read of published sources, not an official ruling. Confirm with the Westminster building department before you pull a permit.