Cities Keep Banning ADUs in Fire Zones. HCD Keeps Pushing Back.

You've got the backyard, you've priced the build, and then you pull up your city's ADU code and hit a wall: your lot sits in a Very High Fire Hazard Severity Zone, and the ordinance says no ADU there — full stop. From Los Angeles to Dana Point, cities keep writing that same rule.

Here's the thing: HCD keeps telling those cities the fire-zone label, by itself, isn't a reason.

HCD's line: a zone map isn't a justification

Reviewing the City of Los Angeles's ADU ordinance, HCD quoted the exact language it took issue with:

"No ADU is permitted on any lot that is located in both a Very High Fire Hazard Severity Zone…"

HCD's position is that a flat prohibition like this oversteps what state law allows. Government Code § 66314(a) lets a jurisdiction designate where ADUs may be permitted based on "the impact of accessory dwelling units on traffic flow and public safety" — but HCD found the City "has not adequately demonstrated that ADUs will impact public safety in the VHFHSZ." Its instruction: the city must either remove the prohibition or provide, by resolution, specific evidence of areas within the zone where ADUs would actually impact public safety.

Verified against HCD's findings letter to the City of Los Angeles reviewing its ADU ordinance (November 19, 2024), Finding 4.

The fire-zone label is a building standard, not a ban

This is the part homeowners miss. A VHFHSZ designation drives how you build, not whether you can. HCD spelled it out reviewing Dana Point's ordinance: while CalFire maps set building-design standards such as required building materials, "these zones do not limit the locations where ADUs may be permitted," and "these building standards and requirements do not prohibit the siting of ADUs."

HCD made the same point to Rancho Palos Verdes, noting that "the VHFHSZ mapping was not intended to serve as a development moratorium." Instead, HCD said an ADU in a VHFHSZ "must conform with standards set forth in Chapter 7A of the California Building Code (CBC), Chapter 49 of the California Fire Code (CFC), and the Minimum Fire Safe Regulations…" — plus the familiar 100-foot defensible-space clearance. Those are objective, buildable standards. A blanket "not here" is not one of them.

What a city actually has to do

If a jurisdiction still wants to restrict ADUs in the zone, HCD's position is that it can't just point at the map. Reviewing Agoura Hills, HCD said flatly that a "Very High Fire Hazard Severity Zone (VHFHSZ) designation was not in itself adequate grounds to restrict ADU development," and that under Government Code § 66326 a city adopting an ordinance in conflict with HCD "shall include findings in its resolution adopting the ordinance that explain the reasons the local agency believes that the ordinance complies with this section despite the findings of the department." Those findings, HCD added, "must be fact-based and demonstrate a clear connection to the issue at hand."

HCD has said the same about access rules dressed up as fire safety. Its conclusion to Los Angeles County: the County "may not deny ADU applications in VHFHSZ areas due to a lack of two vehicular means of egress without making the necessary findings to justify such a restriction."

Why this matters for your project

If your lot is in a fire-hazard zone and your city's ADU code reads like a flat ban, these letters suggest the barrier may not hold up — the zone label alone isn't a reason a city can lean on. What it can apply are the objective fire-safety standards: Chapter 7A construction, defensible space, and the like.

One caution: HCD's letters are its enforcement position, not settled law. Courts are the final word, and only a housing-element decertification self-executes. So before you rely on any of this, confirm the current code with your building department — and, if a permit is on the line, your own counsel. This isn't legal advice. But the pattern across five jurisdictions is consistent, and it's worth knowing which line in your city's code the state has been pushing back on.

What CrossBeam does with it

When the letter lands on your desk, CrossBeam turns it around the same day: what each item is actually asking, the code or law behind it, and a written response you can hand to your team or your attorney — the back-and-forth that used to eat weeks, done in a couple of hours.