No national WUI construction code

The United States has no federal WUI construction book for a private house. Executive Order 13728 (18 May 2016) points Federal agencies at the current IWUIC, or an equivalent nationally recognized code, for Federal buildings greater than 5,000 square feet on Federal land in moderate or greater WUI risk. That is not your permit. IWUIC binds a lot only where a jurisdiction adopts it.

You are looking at a roof bid in a state with no statewide WUI book and asking whether “the national IWUIC” is the spec. It is a model. The building official names the adopted edition, or tells you there isn’t one.

Why it matters

Embers do not wait for a federal house code. The T0 answer in most states is ordinary building code plus a voluntary program such as IBHS Wildfire Prepared, plus whatever local overlay actually exists. Pretending EO 13728 is a nationwide residential mandate sends the wrong book to plan review.

How it works

USFA’s implementation guidelines, opened 26 August 2026, say the order covers Federal agencies that design or own those Federal buildings, lease space in newly constructed buildings for predominant Federal use over 5,000 rentable square feet, or help finance named projects in mapped moderate-or-greater WUI. The guidelines state they are advisory only and create no right or benefit enforceable against the United States.

The same PDF quotes 2015 IWUIC §101.2 as applying to construction, alteration, movement, repair, maintenance, and use of buildings within wildland-urban interface areas. That extract is the guidelines’ quotation of the 2015 model. This session did not retrieve 2024 Chapter 1 body text from ICC Digital Codes (the title page loaded; the chapter required a Premium login). Spec the edition the official names.

The paths

1. Adopted local or state WUI book. Spec that book. See how to read a state page.
2. No statewide WUI book sourced. Ordinary IBC/IRC unless a county overlay exists. Example: Wyoming WUI code status.
3. Harden anyway. Ready.gov for household moves; IBHS if you are getting ready for a designation inspection.

Arizona: the adoption switch in practice

A.R.S. 11-861(D) says a county board may adopt a current WUI code after a public process. A.R.S. 9-806(A) separately says a city or town may adopt one. Neither provision makes the national model book your statewide residential permit rule by itself. The practical question is which local ordinance and edition were actually adopted. The Arizona WUI status guide carries the local examples and the current source boundary.

Wyoming: the state list is not the local overlay

Wyoming’s Council on Fire Prevention Chapter 1 names five current ICC code families but not IWUIC. That is evidence against a statewide IWUIC house book, not evidence against every local overlay. Jackson and unincorporated Teton County each adopted a separate 2024 IWUIC application with its own boundary and effective date. The national model still needs that local legal bridge. See Wyoming WUI code status.

New Mexico: local adoption can also remove the construction chapter

New Mexico’s statewide construction books are the 2021 IBC and IRC, not IWUIC. Santa Fe County separately adopted the 2021 IWUIC and deleted Chapter 5. That is a local authority and a reduced local book—not a national mandate, not a statewide New Mexico roof book, and not proof that nothing else in the County overlay remains. See New Mexico WUI code status and what deleting Chapter 5 removes.

Florida: a statewide building code is not a statewide WUI code

Florida does have a statewide construction book, but F.S. 553.73 names the model families used to update it and does not name IWUIC. The Florida Fire Prevention Code is a separate NFPA path. Lightning fire, hurricane provisions, and a national wildfire model are three different facts; none silently inserts IWUIC Chapter 5 into the Florida Building Code. See Florida WUI code status.

Texas: municipal building authority is not a statewide WUI overlay

Texas Local Government Code 214.212 adopts the IRC as a municipal residential building code and provides a municipal amendment process. It does not name IWUIC. Austin separately adopted and mapped a 2024 WUIC for its own project criteria; that local bridge does not turn the model into a Texas statewide house code or extend it to an unopened city ordinance. See Texas WUI code status.

What people mix up

• Treating ICC’s model PDF as automatically in force on a private lot.
• Treating EO 13728 as a homeowner construction mandate.
• Importing Oregon R327 or California CWUIC because “the feds use IWUIC.”

How to check

1. Ask the building official which WUI book, if any, is adopted, and which edition.
2. Open this site’s state WUI-status guide when one exists.
3. If the official names IWUIC, spec that adopted edition — not “the federal EO.”

Limits

This page does not classify a parcel. It does not quote 2024 IWUIC section numbers from an unopened chapter. It does not decide a permit.

Related records

• IWUIC
• How to read a state page
• USFA: WUI is not only the West