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When the overlay map decides the eave
A line on a city overlay map can decide whether the eave is an IWUIC eave. Idaho does not adopt IWUIC statewide. Eagle 7-1G-3 adopts the 2018 IWUIC, including Appendices A and B, only within the IWUI overlay district. 7-1G-2 then lets a city-approved fire-protection plan take a project back out of that article. Ask where the lot sits relative to the line.
You are looking at a Boise Foothills lot just inside, or just outside, Eagle’s overlay and asking whether last year’s roof detail still works. The statewide path is ordinary IBC or Idaho residential code. The overlay path is 7-1G. This site does not read your parcel. See Idaho WUI code status.
Why it matters
Embers do not stop at a GIS line. The permit does. Specifying “Idaho IWUIC vents” names a book the state did not adopt. Specifying 2018 IWUIC on a lot outside the overlay names Eagle’s map as if it were the city limits. Specifying the overlay book and skipping a required fire-protection plan misses the exemption path the ordinance actually wrote.
How it works
7-1G-3 (Ord. 947, 12 August 2025) adopts the 2018 IWUIC as published by ICC, as amended by the city, including Appendix A and Appendix B. Those provisions are controlling within the limits of the IWUI overlay district.
7-1G-2 names the map: the Wildland-Urban Interface Overlay District Map adopted by Ordinance 947, on file at the City Clerk. The article applies to new subdivisions, new construction, additions, alterations, and moving or change of use of residential, commercial, or industrial structures within that overlay. If 7-1G conflicts with other Eagle City Code, the more restrictive controls.
The same section then writes an off-ramp. Any project or development with a city-approved Fire Protection Plan prepared by a Certified Wildfire Mitigation Specialist or stamped by a Fire Protection Engineer shall be exempt from the regulations in that article.
7-1G-4 amends IWUI 108.5 so a fire-protection plan (the city also calls it a Wildfire Safety and Mitigation Plan) is prepared by that same specialist or engineer where the official requires it under Section 405. The plan is incorporated into CC&Rs and subdivision approvals. Additionally, the code official may require lots or land that abut or are contiguous to the overlay to have that plan. The line is not the whole story.
7-1G-4 also amends 602.1: an approved automatic sprinkler system may be required in new buildings that must meet Class 1 ignition-resistant construction in Chapter 5. Appendix B vegetation-management content is rewritten so the plan lives in the CC&Rs with a funding mechanism, and the city may audit every five years.
Eagle publishes the Ordinance 947 overlay map on its Plans & Maps page. The map depicts the adopted overlay, but it is not a parcel determination and it does not select a construction outcome. 2018 IWUIC Table 503.1 separately combines the official wildfire-hazard severity with water-supply and defensible-space conditions. The table can return IR1, IR2, IR3, IR1 plus the N.C. exterior-wall condition, Not Required, or Not Permitted.
When the official outcome includes an IR class, that class changes the roof path: IR1 is Class A, IR2 is Class B or better, and IR3 is Class C or better. The 2018 vent-mesh path belongs only to IR1 and IR2 and specifies noncombustible corrosion-resistant mesh with openings no larger than one-quarter inch; soffit and eave-overhang vent locations remain prohibited. FireApproved models 15 conservative IR1/IR2/IR3 product-field paths. It does not project the N.C., Not Required, or Not Permitted outcomes. Those are 2018 rules. A 2024 requirement row is not a substitute.
The paths
| Location relative to the overlay | What 7-1G does |
|---|---|
| Inside the Ordinance 947 map | 2018 IWUIC, Appendices A and B, as amended, on new work, additions, alterations, moving, and change of use |
| Inside, with a city-approved Fire Protection Plan | Exempt from the article, if the official approved that plan |
| Abutting or contiguous to the overlay | Not automatically inside 7-1G-2. The official may still require a Wildfire Safety and Mitigation Plan |
| Elsewhere in Eagle, or elsewhere in Idaho | Ordinary IBC / Idaho residential code unless another overlay exists |
- Ask whether the lot is in the overlay. Then ask whether a fire-protection plan is required or already approved.
- Ask for the full Table 503.1 outcome. The overlay polygon alone does not select IR1, IR2, IR3, IR1 + N.C., Not Required, or Not Permitted.
- Do not spec statewide Idaho IWUIC. There isn’t one. See Idaho WUI code status.
- Harden anyway. IBHS is a designation, not adopted code.
What people mix up
- Treating Eagle’s overlay as Idaho statewide IWUIC.
- Treating a lot just outside the polygon as automatically free of 7-1G-4’s abutting-lot plan.
- Writing “IWUIC” without the 2018 year and the overlay.
- Treating overlay inclusion as an automatic IR1/Class A assignment.
- Treating a consultant’s fire-protection plan as an exemption before the city approves it.
- Importing Oregon R327 or California CWUIC onto an Eagle drawing.
- Treating 7-1G-4’s “may require” sprinklers as a statewide 13D mandate.
How to check
- Ask the building official whether the lot is in the WUI overlay adopted by Ordinance 947.
- Open 7-1G-2, 7-1G-3, and 7-1G-4.
- Ask which Table 503.1 hazard, water-supply, and defensible-space conditions control the full outcome.
- Ask whether a Fire Protection Plan is required, already approved, or being used as the 7-1G-2 exemption.
- If the lot only abuts the overlay, ask whether 108.5’s contiguous-lot sentence applies.
- This site does not read your parcel.
Limits
This page joins Eagle 7-1G-2, 7-1G-3, and 7-1G-4 to the official ICC 2018 Chapter 5 text. It does not classify a parcel, hazard, full Table 503.1 outcome, project, effective date, Fire Protection Plan, or official approval. It does not extend Chapter 5 to land that merely abuts the overlay, and it does not decide Boise’s IFC Chapter 41 overlay.
Related records
- Idaho WUI code status
- Eagle place record
- How WUI is mapped
- The IWUIC edition on the lot
- IWUIC model book
Questions
Does every Idaho lot take IWUIC eaves?
No. Idaho has no statewide IWUIC construction book. Eagle 7-1G-3 adopts the 2018 IWUIC, including Appendices A and B, only within the IWUI overlay district. Ask whether the lot is inside that map. See Idaho WUI code status.
What if my lot is just outside the overlay line?
7-1G-2 applies the article inside the overlay. 7-1G-4 (IWUI 108.5) also lets the code official require a Wildfire Safety and Mitigation Plan on lots or land that abut or are contiguous to the overlay. Being outside the polygon is not an automatic pass. Confirm with the building official.
Can a fire-protection plan take the house out of 7-1G?
7-1G-2 says any project or development with a city-approved Fire Protection Plan prepared by a Certified Wildfire Mitigation Specialist or stamped by a Fire Protection Engineer shall be exempt from the regulations in that article. That exemption is the official’s approval, not a drawing note.
Does the overlay also bind additions on an older house?
7-1G-2 applies to new subdivisions, new construction, additions, alterations, and moving or change of use of residential, commercial, or industrial structures within the overlay. Confirm the job with the building official.
Does the overlay map determine whether my roof is Class A, B, or C?
No. The map depicts overlay reach. The 2018 IWUIC Table 503.1 separately uses wildfire hazard, water supply, and defensible space. Its outcomes include IR1, IR2, IR3, IR1 + N.C., Not Required, and Not Permitted. The 15 modeled rows cover only conservative IR1/IR2/IR3 product-field paths; confirm the full outcome with the code official.
Is this Idaho’s book?
No. It is Eagle’s overlay. See Idaho WUI code status.