External Threat: Protecting Your Property when the Fire Starts Outside

In early 2025, a 30,000-square-foot steel warehouse full of storage was destroyed by fire — and deemed a total loss.

The building, located in the Southwest, was well maintained and featured a working automatic sprinkler system. The fire started outside the building in the open dry brush and was fueled by wind and an unusually arid winter. Flames spread quickly across the open field, igniting wooden crates stored outside the warehouse and quickly engulfed the building and contents. The fire protection sprinklers were overwhelmed, and the extreme heat collapsed the roof.

As dry conditions, rising temperatures and high winds become more common, so do these scenarios. Nearly one-third of all housing units in the contiguous U.S. are now located in wildland–urban interface zones, and commercial development is following similar patterns.  In 2024 alone, wildfires in these areas destroyed over 4,500 structures, including 80 commercial or mixed-use buildings.  Such conditions also expose a critical gap in many fire prevention plans: Internal systems are only one layer of defense — and often the last.

Whether you’re storing goods, housing vehicles or managing a warehouse, external threats could determine whether your property survives a fire. Here are key lessons from this loss and practical steps building owners can take to minimize fire risk from external exposures. 

The most common external fire hazards

To protect commercial properties in today’s fire-prone environments, building owners must shift their focus from containment to prevention. That means reducing fuel sources, creating defensible space and addressing the risks that exist outside the structure itself. 
Common external fire hazards include: 

• Dry vegetation such as brush, weeds and tall grass
• High winds that drive fire toward and around buildings
• Combustible storage like wooden pallets, crates, cardboard and plastic bins
• Neighboring properties or infrastructures that may introduce unintentional fire risk, such as rail lines, utility poles and transformers 

It’s also important to recognize that steel buildings — often assumed to be more fire-resistant — are not immune to structural failure. Under extreme heat, steel loses strength and can bend or collapse. No matter the type of structure, it’s crucial to be aware of the hazards that may go unnoticed but often add fuel to a fire.

5-point checklist to reduce external fire risk

Here are five best practices to help minimize external fire exposure and strengthen your property’s resilience:

1. Eliminate combustible outdoor storage

• Avoid storing flammable materials like wooden crates or plastic containers near your building.
• Keep overhangs, loading docks and covered walkways free from combustible materials. Pallets or equipment stored in these semi-enclosed areas can allow fire to bypass your internal protection systems.
• If outdoor storage is unavoidable, place it as far from structures as possible and maintain clear separation.

2. Maintain a defensible perimeter

• Regularly clear brush, tall grass, weeds and debris from around your property.
• Keep landscaping trimmed and well-maintained near buildings, docks and fence lines.

3. Be mindful of the parking layout 

• Don’t park trucks, trailers or fleet vehicles directly against your building overnight.
  Create designated parking zones with safe distance to minimize the risk of fire spreading between vehicles and structures.

4. Update detection and alarm systems  

• Ensure all fire detection and alarm systems are installed, regularly tested and up to code.
• While these systems can’t stop an external fire, they can provide critical early detection and warning.

5. Think beyond your property line 

• Monitor neighboring properties for untrimmed vegetation, trash or risky storage that could impact your business.
• When possible, coordinate with adjacent owners to address shared risks and prevention efforts.

Insurance can help cover the financial impact of a loss, but proactive prevention is the best protection. By recognizing and addressing external fire risks — before they reach your building — business owners can reduce exposure, protect operations and strengthen long-term resilience.

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