Hill terrain at dusk with a wildfire burning along the ridge line. A risk surface is painted onto the ground and follows the topography — red along the ridge and down the canyon that runs toward the property, cooling through yellow and green to deep blue on the flanks — with a lit house at the foot of the canyon

FireShield Risk

Wildfire risk, calculated the way earthquake risk is

Not a color on a county map. A probability for your property, based on where fires start, how often they get large, and how easily fire can spread across the land between them and you.

The method

Using a method earthquake engineers have relied on for fifty years

Structural engineers stopped asking “is this an earthquake area?” a long time ago. They ask a sharper question: for this building, what is the chance of exceeding a given level of shaking in a given period? That question is answered by probabilistic seismic hazard analysis, and every building code in California rests on it.

Wildfire risk is still usually described the old way: a zone, a tier, a color on a map. Our founder spent his career on the second kind of question, and FireShield’s hazard model is built with the same three pieces.

The three components of a probabilistic hazard model, in earthquake and wildfire terms
The piece	Earthquake	Wildfire
Where it can start	Faults, and how often each one ruptures.	Ignition sources and their spatial density — lightning, powerlines, roadsides, equipment. Some ground simply starts more fires than other ground.
How big, how often	A recurrence relationship: many small earthquakes, few large ones.	The same shape, and more extreme. A small minority of fires account for most of the burned area, so a model based on the average fire gets the real risk wrong.
What reaches you	A ground-motion prediction equation: rupture to shaking at your address, through distance and soil.	A landscape relationship: ignition to fire intensity at your address, through fuel, terrain and weather. This is the most important part, and the hardest to calculate.

The one that matters most. In earthquake work, engineers calculate how an earthquake’s shaking travels through distance and soil to your address. Wildfire needs the same calculation, and it is harder: the land in betweencan burn, fire spreads more in some directions than others, and embers on the wind can jump over it completely. Everything below is what that one term has to account for.

What the model has to carry

Six things that decide whether a fire two miles away can reach your home

Burned land doesn’t burn again easily

Land that burned two years ago does not burn well. A road or a watercourse stops it. So the risk at your address changes as the land around you changes, even if nothing changes at your home.

Wind and slopes change how fire spreads

Fire does not spread as a circle. Wind elongates it downwind; it climbs far faster than it crosses or descends. Two houses on one street can carry very different risk.

Embers can jump ahead

Embers travel on the wind and land well ahead of the front. That is what actually ignites houses — and it means a home can be at real risk even when there is no continuous brush between it and the fire.

Whether anyone can get there

A fire gets large when it spreads faster than firefighters can contain it. In strong winds, many fires compete for the same limited crews and aircraft — so the odds of a large fire rise exactly when several are burning at once.

Neighboring homes can burn too

At the wildland–urban interface, structures ignite structures. On a dense street, what your neighbors have done to their roofs is part of your hazard.

Your own house

Hazard is the fire that reaches you. Damage is what it does to your house — roof, vents, eaves, siding, defensible space. Which is why the model can answer a useful question: what changes if you harden this part.

The output

Every house gets its own risk score

When you apply these factors to the real land, you no longer get one number for your whole ZIP code. It becomes a value for each individual property, recomputed as conditions change.

Neighbors come out differently. A house right at the canyon edge, with continuous brush running uphill to it, carries a different number from one three houses down that sits behind other homes and a road. Same street, same fire, same distance on a map.

That makes it useful. It shows which side of your property raises your risk the most, so you clear the brush that matters, not just the brush that looks messy.

Ask about your property How the system responds

As the fire comes down the canyon, the risk around the property changes with it. The number is not fixed — it is recomputed as the fire moves.

The same method insurers use

A burn probability for every coordinate around your house

Insurers and reinsurers do not price earthquake risk from a zone map. They run probabilistic catastrophe models — every plausible rupture, how often it happens, and what it does to each insured building — and set capital and premiums on the result. FireShield brings that same discipline to wildfire.

The ground around a property is divided into cells, and each one carries its own burn probability, driven by where the fire is, the wind, the fuel and the terrain, and extended with burn history, drought, forecast, access roads, concurrent fires, suppression resources and water nearby. Every cell is recomputed continuously, so the picture moves as the fire does.

It was designed by our founder, who holds a PhD in earthquake engineering and probabilistic seismic hazard analysis — the field that underpins seismic building codes and catastrophe insurance — to use that same careful method where it helps most: protecting homes and the communities around them, and to act on the result instead of just putting it in a report.

Engineering drawing: a grid of burn-probability values around a protected house, high near the fire and brush, falling away downwind, with the fire approach vector and wind direction — Burn probability, cell by cell, as the fire approaches a protected house — from our patent.

Before and during a fire

One model answering two different questions

Before the season — planning

Running periodically, it produces the standing hazard for a property: how exposed it is, what is driving that, and what would change if the roof, the vents or the defensible space changed. This is the question an insurer, a builder or an owner deciding where to spend money is actually asking.

During a fire — operational

During a fire, the same model uses live data — the sensed perimeter, the weather forecast, what suppression resources are committed — to estimate how long until the fire reaches the property and how likely it is to reach it in the next few hours. It updates as new data comes in.

The two feed each other. Where a fire actually burned changes the fuel the planning model assumes next time, so last season’s fires change this season’s risk map.

Why this is not a dashboard

The result turns on the sprinklers

Plenty of organizations compute wildfire risk. The output is almost always a map, a score or a premium. FireShield’s connects to physical hardware at the property: the same live fire data behind the number is what the FireShield system watches, and it starts the water on its own, fully automated and zero touch.

Our patent covers this: a risk calculation for each property that directly turns on the sprinklers, instead of just showing a number on a screen.

This page gives an overview of the model, not the technical details: which quantities go in, what comes out, and why each term is there. No system can eliminate wildfire risk, and no model can predict a particular fire. But both can lower the chance of being caught off guard.

Talk to us about your property Who built this