IBHS adds neighborhood and multifamily wildfire standards for Western builders

The Insurance Institute for Business & Home Safety (IBHS) has expanded its Wildfire Prepared program with new standards for neighborhoods and multifamily buildings and updated requirements for single-family homes, creating a more complete design roadmap for builders in fire-prone communities.

The nonprofit research organization announced the changes in an IBHS release, framing them as the final major pieces of a program aimed at helping the housing industry reduce wildfire losses through design, materials and site planning, rather than relying solely on emergency response.

For homebuilders working in the West and other wildfire-exposed regions, the expanded standards offer a clearer set of design and construction practices that can be applied at the lot, building and community scale. They are intended to complement model codes and may be adopted voluntarily by developers, builders, local governments and HOAs.

What changed in the Wildfire Prepared program

According to IBHS, the program now includes:

• Neighborhood standards that address how homes are sited and spaced, street layout, vegetation management in common areas and edge conditions at the wildland-urban interface.
• Multifamily standards focused on attached and stacked housing types, where shared walls, decks and vents can increase pathways for ember intrusion and structure-to-structure fire spread.
• Updated home requirements for single-family detached homes, refining earlier guidance on roofs, vents, decks, gutters, siding and the immediate 0–5 foot zone around structures.

The neighborhood and multifamily components are meant to “round out” earlier single-family guidance, creating a more integrated framework so that resilience is not undermined by adjacent properties or common spaces, IBHS said.

Why this matters for builders and developers

Wildfire risk has become a core land-use and underwriting issue in much of the West. In California and other high-risk states, insurers have pulled back in some markets, regulators are reassessing property-insurance rules and local governments are tightening building and defensible-space requirements.

For production and custom builders, the IBHS framework may serve several functions:

• Design baseline in high-risk markets: A structured checklist of wildfire-resistant assemblies and site features that can be integrated into standard plans and community design guidelines.
• Risk conversations with capital and insurers: A third-party, research-based framework that can be cited in discussions with insurers, equity partners and lenders about long-term property risk and insurability.
• Differentiation in competitive subdivisions: A way to formalize “fire-wise” or resilience branding through specific standards on lot layout, materials and landscape, rather than general marketing language.

IBHS bases its recommendations on testing at its research facility, where it studies how embers, direct flame contact and radiant heat cause home ignition. The updated program continues to emphasize the vulnerability of the first five feet around a building and details how to treat that zone with noncombustible materials and controlled vegetation.

Key elements for neighborhood and multifamily design

While the press materials do not read like a prescriptive code, they highlight several themes that can be translated into development decisions:

• Building separation and orientation: Guidance on spacing, staggering and orientation to reduce structure-to-structure ignition potential.
• Common-area fuels: Treatment of open space, slopes, greenbelts and recreational areas so they do not become conduits for fire approaching homes.
• Edge conditions: Specific attention to lots that back up to wildland fuels, including fencing, outbuildings and landscaping at the perimeter.
• Multifamily vulnerability points: Details for attached garages, shared attics, exterior stairs and stacked decks/balconies that can otherwise allow fire to move quickly through a building.

For multifamily developers, incorporating these details at the entitlement and early design stages can be less costly than retrofitting later and may support more stable operating costs if insurance markets continue to tighten in wildfire corridors.

How builders can use the IBHS standards

Unlike building codes, participation in the Wildfire Prepared program is voluntary. IBHS positions it as a resource that can be written into:

• Developer design manuals and pattern books
• Architect and engineer scopes of work
• HOA CC&Rs and landscape guidelines
• Local incentive programs for resilient construction

Embedding wildfire-resilient details at the community planning level can also reduce friction with local fire authorities during approvals, particularly in jurisdictions where wildfire evacuation and access are already political flashpoints.

For builders, the practical question is cost and constructability. IBHS materials note that many wildfire-resistant features involve material substitutions (such as ember-resistant vents, Class A roofs and noncombustible surfaces near the home) and site-planning decisions that can be incorporated into standard workflows, rather than bespoke custom solutions.

Regulatory and market backdrop

The expanded Wildfire Prepared program lands amid a broader recalibration of fire risk in the housing market:

• Western states continue to rewrite codes and defensible-space rules as fire seasons lengthen.
• Insurers in California, Colorado and other states have either tightened underwriting or requested rate increases tied in part to wildfire exposure.
• Investors and lenders are asking more pointed questions about physical climate risks to housing assets.

In that context, standardized, research-backed design guidance can help homebuilders and multifamily developers respond consistently across projects, rather than on a jurisdiction-by-jurisdiction basis.