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Home-hardening ladder
This page is an order of operations for an existing house. It maps CAL FIRE’s low-cost retrofit list and FEMA P-737 onto the categories already on this site. The labels $0 / about $500 / about $5,000 are sequence bands. They are not prices. CAL FIRE does not print those dollar amounts. This page does not invent them.
You are on an existing house that will never see an R327 new-dwelling permit. Empty the five feet and the gutters before you buy a listed vent.
Why it matters
Most existing houses will never see an R327 new-dwelling permit. They still collect embers. CAL FIRE’s home-hardening page and the AB 38 low-cost retrofit list are the public retrofit spine. FEMA P-737 is the federal builder’s fact-sheet set. IBHS is a designation, not this ladder.
How to read the bands
Do the first band before you buy a listed vent. Do the second before you re-roof. A Class A roof over a bark bed is the wrong order.
| Band | What it means | Not a price |
|---|---|---|
| $0 | Work you can do with time and a rake | Not “free forever” if you hire it out |
| About $500 | Small hardware. Mesh, covers, caulk, arrestors | CAL FIRE does not quote $500 |
| About $5,000 | Replacement of a component when it is due | Roofs and windows can cost more. This page does not invent a quote |
The rungs
1. $0. Maintenance and Zone 0. Empty the roof and gutters. Pull bark, wood chips, and stored fuel out of the first five feet. CAL FIRE and IBHS both start here. See landscaping and bark mulch. Oregon’s State Fire Marshal names river rock, gravel, or pavers in that buffer. This is not R327.
2. About $500. Close the holes. CAL FIRE’s list: noncombustible gutter cover; chimney spark arrester (3/8 to 1/2 inch metal mesh); caulk gaps greater than 1/8 inch at rafters, blocking, and siding; garage-door weather-stripping where the list names UL 10C. Cover attic and underfloor vents with 1/16–1/8 inch metal mesh if you are not yet buying a listed assembly. See foundation vents and mesh versus listed.
3. About $5,000. Replace the weak component when it is due. CAL FIRE: ember- and flame-resistant vents (OSFM WUI products); multi-pane windows with at least one tempered pane when you replace windows; Class A roof when you replace the roof; noncombustible or ignition-resistant siding or decking when you replace those assemblies. Bird stops at the roof edge. Do not invent a listing ID.
4. Not on this ladder. New-dwelling R327 paths. ADUs and shops. Craftsman eaves. Community exhibits.
FEMA P-737 Vents Fact Sheet #8 and Gutters Fact Sheet #9 cover the same holes for existing buildings. Check the adopted code before you change airflow.
What people mix up
- Treating the dollar labels as bids.
- Buying 8165 vents before emptying Zone 0.
- Treating this list as Oregon R327. See remodels.
- Skipping mesh because a brochure said “listed only.” CAL FIRE still prints the mesh cover as a path.
How to check
Walk the five feet, the gutter, and every vent. Then open CAL FIRE’s list. Match each item you actually did. If you also want IBHS, Essential is a different checklist. If R327 applies, it is a different permit.
Limits
This page does not price your house. It does not stamp a permit. The 1 January 2026 CAL FIRE list is California retrofit guidance. Oregon may still use mesh and metal gutters as voluntary work.
Related records
Vents, gutters, landscaping, CAL FIRE BML.
Sources
Questions
Are the dollar bands prices?
No. CAL FIRE’s low-cost retrofit list does not print those dollar amounts. The bands are an order of operations so you do not buy a Class A roof before you empty the gutter. If a source does not price an item, this page does not invent one.
Does this ladder replace Oregon R327?
No. R327, where adopted, is new construction of new ORSC buildings. This ladder is retrofit guidance from CAL FIRE and FEMA. See remodels when the answer is no.
What is the first move?
Remove debris and combustible groundcover in the first five feet, and empty the roof and gutters. CAL FIRE and IBHS both start with maintenance. That work does not need a listing ID.
Do I need listed vents on day one?
CAL FIRE’s list allows ember- and flame-resistant vents or, as a temporary cover, 1/16–1/8 inch metal mesh. Oregon R327.3.2 uses the same mesh range for attic and underfloor openings. Eave undersides are a different sentence.