Metal buildings for wildfire zones (California, Colorado)

If you live near the trees, hills, or open range, you know the routine. Fire season shapes your year. You keep a go-bag by the door. You ask “what if” more than you’d like.

Now you’re planning a shop, garage, barn, or ADU. A hard question follows. Will it survive a fire? And will your insurer still cover it?

Are metal buildings good for wildfire zones? Yes. Metal buildings are non-combustible, so they resist ignition from embers and radiant heat far better than wood. Pair one with ember-resistant details and defensible space, and you have one of the strongest options in California and Colorado.

This guide gives you honest answers. You’ll see what works, what doesn’t, and what each state requires.

At Metal Pro Building, we help property owners in fire-prone areas of California and Colorado build with confidence. Here’s what we’ve learned.

Why Wildfire Zones Demand a Different Way of Building

Most people picture a wall of flames when they think of a house fire in the hills. That picture is wrong, and it leads to the wrong choices.

How Wildfires Actually Destroy Structures

Most structures ignite from wind-blown embers, which are small burning bits of plants or building materials that can travel more than a mile ahead of the fire front. The flames often arrive later, if they arrive at all.

Picture a handful of glowing embers landing on your roof. One drops into a vent. Another settles in a gutter full of dry needles. Nobody is watching, and nobody has to be there for it to start.

Embers find the weak link, and vents are often the most vulnerable part of a house. IBHS testing found that vents facing into the wind let in the most embers.

So the question isn’t only “will fire reach my building?” It’s “what can an ember catch on?”

Why Wildfire Risk Keeps Growing in California and Colorado

Two things are happening at once. More people live where homes meet wildland. And fire seasons keep stretching.

That meeting zone is called the wildland-urban interface, or WUI. In California, it’s home to more than 11 million people, about a quarter of the state. Colorado’s WUI grew by 65 percent between 1990 and 2010, compared with almost 20 percent in California.

Seasons are changing too. California now stays dry longer, which pushes fire season deeper into autumn, when strong winds pick up. A 2021 study found that 15 of California’s 20 most destructive fires happened since 2014. 

Two fires show what that looks like:

• Camp Fire, California (2018): It destroyed over 18,000 structures and killed 85 people.
• Marshall Fire, Colorado (2021): It destroyed nearly 1,100 homes and caused $2 billion in damage, fed by drought and winds gusting up to 100 mph. It hit suburbs, not remote forest. And it came in late December. 

Big fires also create rebuild pressure. After the Marshall Fire, one of the first questions was where displaced families would live. Owners want to rebuild fast. They also want to rebuild safer. 

The Emotional Weight of Building Near Fire Risk

We won’t pretend this is easy. Choosing a building here feels different than it does elsewhere.

You’re not only picking a floor plan. You’re asking if the shop that holds your tools, the barn that shelters your animals, or the ADU that houses your family will still be standing. That’s a heavy question.

It’s okay to feel that weight. It means you’re taking the risk seriously. And it’s a good reason to be picky about materials.

Fear isn’t the goal here, though. You can’t control the wind or the season. You can control what you build and how you build it.

The materials you choose change the odds. Let’s look at what metal does well.

Are Metal Buildings Fire-Resistant?

Yes. Steel is non-combustible, so it gives embers nothing to burn. Metal roofing can carry a Class A fire rating, the highest level in standard roof tests. No shingles or shakes mean fewer places for embers to catch. Metal buildings are fire-resistant, not fireproof, so the details still matter.

Fire-Resistant vs. Fireproof: What the Terms Really Mean

Fireproof sounds nice. It’s also not true of any building.

Fire-resistant means a material resists ignition and slows the spread of fire. That’s the honest claim for metal, and it’s a strong one.

Here’s how roofs get tested. UL 790 sorts roofing into Classes A, B, and C, based on how well it resists flames, limits flame spread, and resists embers. Class A is the top grade. Galvanized steel, aluminum, and copper roofs all earn Class A under this standard.

One catch. Metal roofing is rated as a full assembly, so the layers underneath must match the manufacturer’s specs to earn that rating. The panel alone doesn’t carry the rating. The whole system does. One catch. Metal roofing is rated as a full assembly, so the layers underneath must match the manufacturer’s specs to earn that rating. The panel alone doesn’t carry the rating. The whole system does. 

And even Class A isn’t a force field. These tests don’t prove a roof will come through undamaged. 

How Steel Behaves in Extreme Heat (and Why Engineering Matters)

Steel doesn’t burn. It does soften when it gets very hot.

Steel melts above 2,500°F, but it loses about 20% of its strength at 750°F and about half at 1,000°F. For comparison, a typical gasoline fire burns at 1,200 to 1,500°F.

Why does this matter for you? A fast-moving wildfire front passes quickly. A long, hot fire fed by a nearby fuel source is a different story. That could be a woodpile against the wall, a stack of pallets, or an overgrown shrub.

This is where design and engineering earn their keep. Siting, clearance, and defensible space keep heat away from the frame. A well-engineered steel structure also gives you a margin that wood simply doesn’t have.

Why Embers Are the Real Enemy (and How Metal Helps)

Remember the earlier section: embers cause most home ignitions. They look for a place to land and a fuel to catch.

Metal takes away a lot of those places. Metal roofing doesn’t ignite, and it limits spots where embers can settle and light debris. There’s no wood shake to smolder and no asphalt to curl.

Still, an ember doesn’t need your roof. It can slip through a vent or sit in a gutter full of leaves. IBHS testing found vents were a weak point, especially when they faced into the wind. 

So metal is a great start. It isn’t the whole answer. Think of it as the strong frame that your ember-resistant details hang on. We’ll cover those details in the checklist section.

Metal vs. Wood vs. Traditional Construction in California and Colorado Wildfire Zones

Here’s the short version. Metal wins on fuel, embers, and upkeep. Wood-frame can still be built well, but it starts with more to defend.

What You Gain Beyond Fire Safety

The lifespan numbers matter more than they look. Metal roofs can last 40 to 70 years, while asphalt shingles typically need replacing every 15 to 30 years. That means you could re-roof a shingle building two or three times during one metal roof’s life.

Upkeep drops too. Metal roofs need less maintenance than asphalt or wood shakes. Wood is more demanding. A wood shingle roof should be inspected every year, and split shingles replaced promptly. 

Fire risk is the bigger gap. Wood shingles are prone to fire, and some municipalities ban untreated ones. Metal removes that problem from the start. 

Now the honest part. Metal costs more up front in most cases. Installation costs for metal roofing are higher than for asphalt shingles. You’re paying for the 50-year view. 

And wood-frame isn’t doomed. IBHS testing showed that fiber cement siding and other resistant materials helped a test home resist ember ignition. A wood building with the right details can perform well. It just needs more of them done right. 

Tired of Worrying About Every Ember Season?

Here’s what changes with metal.

You stop asking “what will burn first?” The roof won’t. The walls won’t. The frame won’t. Your attention shifts to the small stuff: vents, gaps, and what’s piled against the walls.

That’s a smaller list, and you can finish it.

Each state adds its own rules on top. California leans on its ignition-resistant building chapter. Colorado leans on wind, snow, and local WUI rules. We’ll take them one at a time.

Metal Building Requirements for Wildfire Zones in California

California’s wildfire building rules changed this year. If you’ve read older guides, they’re probably out of date. Here’s where things stand as of October 2026.

What Is the WUI and California’s Wildfire Building Code?

The WUI (wildland-urban interface) is where homes and wild vegetation meet. If you’re near trees, brush, or open hills, you’re probably in or near one.

For almost 20 years, the key rule was Chapter 7A of the California Building Code. That has changed. Chapter 7A was deleted on January 1, 2026, and its requirements moved into the California Wildland-Urban Interface Code, Title 24, Part 7. Projects with permit applications submitted before that date follow the old code. Applications on or after January 1, 2026 follow the new one.

The goals are the same. The code sets ignition-resistant construction rules for new buildings in the WUI and in fire hazard severity zones. Many local offices and contractors still say “Chapter 7A” out of habit. Expect to hear both names. 

Defensible Space and PRC 4291 Basics

Public Resources Code 4291 is California’s defensible space law. It requires you to maintain defensible space out to 100 feet from the structure, or to your property line, whichever is closer. It applies in State Responsibility Areas and Very High Fire Hazard Severity Zones.

The space breaks into zones. Zone 0 is 0 to 5 feet, Zone 1 is 5 to 30 feet, and Zone 2 is 30 to 100 feet. 

Zone 0 is the tricky one. State law calls for an ember-resistant zone, but the rules haven’t settled. One October 2026 report says the Board of Forestry adopted Zone 0 as an emergency rule on August 19, then the package was listed as withdrawn on September 8, so it isn’t in effect. Check with the Board of Forestry or your local fire authority before you plan around it. Some cities, like San Diego, have adopted their own Zone 0 rules. 

Our advice: build a clear zero zone anyway. It costs little and works.

Fire Hazard Severity Zones and How to Check Your Property

Cal Fire maps land as Moderate, High, or Very High. New construction and renovations in designated zones must follow WUI building codes.

The maps just grew. The 2025 update added about 1.4 million acres to the high and very high zones statewide. A parcel that was outside a zone a few years ago might be inside one now. 

To check, search your address at osfm.fire.ca.gov/fhsz. Then confirm with your county or city building department. Local agencies can add rules on top of the state’s. 

How Metal Buildings Meet Ignition-Resistant Requirements

Does a workshop or garage count? Often, yes. In Santa Cruz County’s State Responsibility Area, for example, WUI requirements apply to all new structures, including garages, workshops, and greenhouses. Some small sheds get exceptions. Don’t count on it for a real building.

Here’s what the code looks at, and how metal fits:

• Roofing: Roofing must have a Class A fire rating. Metal roof assemblies can meet this.
• Vents: Vent openings must be covered with flame- and ember-resistant vents listed by the State Fire Marshal or tested to ASTM E2886. This is where steel buildings can fall short if the details are ignored.
• Eaves and soffits: Open and enclosed eaves have their own material rules.
• Exterior walls: Walls must resist fire exposure. Noncombustible metal panels are a natural fit. Your plans still need to show the exact assembly.
• Windows and doors: Windows need at least one tempered pane, glass block, or a 20-minute fire rating.

The steel isn’t the hard part. The vents, openings, and documentation are.

Rebuilding After a Fire in California

If you’ve lost a building, you’re likely rebuilding under the new code. That’s a good thing in the long run. It also means your old plans may not work.

Pre-engineered metal buildings can cut on-site build time. Permitting, though, is often the slowest step. Your best move is to get the zone, code, and plan requirements settled early.

We can help you understand what your county will ask for before you break ground.

Metal Building Requirements for Wildfire Zones in Colorado

Colorado’s rules also changed recently. And unlike California, there isn’t one rulebook for the whole state. Your county or town matters a lot.

Colorado WUI Codes and County-by-County Variation

Colorado now has a statewide wildfire building code. The Colorado Wildfire Resiliency Code (CWRC) was adopted on July 1, 2025, and it sets minimum requirements for new construction and additions in designated WUI areas .

Local governments then had to act. A 2025 law moved the local adoption deadline to April 1, 2026, with compliance within three months of adoption, so July 1, 2026 in practice. The code covers mapped WUI zones rated Low, Moderate, or High fire intensity..

Here’s the catch. Local governments can be stricter than the state code but not looser. As an example, Garfield County adopted it and removed the state’s 35-acre exemption. And the state hasn’t published a single list of adopting jurisdictions. 

Timing varies too. Larimer County’s version took effect January 1, 2026. Mesa County began enforcing on July 1, 2026. 

What about your shop or barn? Don’t assume it’s exempt. Mesa County, for instance, requires review or a permit for accessory structures in a WUI area, and a list of materials with every review. On roofs, the code language is plain. Roofs must have a Class A rated covering or assembly. Metal handles that well. 

Your move: call your county or town building department. Ask if your parcel is mapped, what class it’s in, and what local changes apply.

Colorado’s Added Challenges: Wind, Snow Load, Altitude, and Dry Seasons

Colorado isn’t only a fire problem. It’s a fire-plus-weather problem.

Wind is the first one. During the Marshall Fire, gusts reached up to 100 mph in places. That fire also came in winter. It followed months of drought and a winter nearly without snow. Fire season here isn’t just summer. 

Then there’s the other side of the year. Snow loads vary a lot between the plains and the high country. Wind exposure changes with elevation and terrain. Every site needs its own engineering.

That’s where steel fits. Pre-engineered metal buildings are designed to specific wind and snow loads for your address. Fire resistance and structural strength can come from the same frame. A building that survives the fire but fails under a heavy snow isn’t a win.

Always give your engineer your exact site address and elevation.

Defensible Space and Colorado State Forest Service Guidance

Colorado uses three zones from the Colorado State Forest Service:

• Zone 1: 0 to 5 feet from the structure, the area nearest the building. 
• Zone 2: 5 to 30 feet, where fuels should be reduced. 
• Zone 3: 30 to 100 feet.

The purpose is simple. Defensible space lowers the chance a building ignites from direct flame or radiant heat .

One detail matters for you. These zones apply around every building on your property, including detached garages, storage buildings, and barns. Your new steel shop gets its own zones.  

And there’s a possible perk. Colorado offers an income tax subtraction for wildfire mitigation work done on Colorado property. Ask your tax pro whether your work qualifies.

Rebuild Lessons From Recent Colorado Fires

The Marshall Fire taught Colorado a lot. Three lessons stand out.

Embers got inside. After the fire, one expert found embers had entered through attic vents, found combustible material, and ignited homes from within. Upgraded vents could have changed the outcome. 

Wood fences were fuses. IBHS found wood privacy fences acted as pathways, spreading fire between homes. Steel fencing is a smarter option.

Everything nearby is fuel. One wildfire expert listed vegetation, RVs, campers, vehicles, trees, barns, and sheds as fuel. That’s a good reminder to site your building with care.

Rebuilders say the same thing about the building itself. The goal is a hardened shell with no gaps. Steel is a good start. The gaps are the work. 

A last practical tip from CU Boulder’s rebuild research: consider hiring a builder with disaster-rebuild experience

What Makes a Metal Building Wildfire-Ready?

A wildfire-ready metal building has six parts. Steel is the base. The other five parts close the gaps.

1. Class A roof assembly and noncombustible panels. Start with a roof tested as a full assembly. Class A is the top grade under UL 790. Use noncombustible wall panels, too. Ask your supplier for the test listing, not just a verbal “yes.” 
2. Ember-resistant vents and soffits. Vents are where many ignitions start. IBHS advises ember-resistant vents or 1/8-inch metal mesh over vents. Enclose eaves with noncombustible material. In California, the code goes further. It calls for flame- and ember-resistant vents listed by the State Fire Marshal or tested to ASTM E2886. One more tip: metal buildings often need airflow to manage condensation. Size your vents with your engineer, so you don’t trade one problem for another. 
3. Ignition-resistant doors and tempered or multi-pane windows. Heat can break glass before flames arrive. IBHS calls for dual-pane windows with tempered glass in both panes, and noncombustible doors with a metal threshold. Seal gaps around garage doors, too. Embers slip through small cracks. 
4. Noncombustible gutters and trim. Vinyl gutters can melt and fall away in a wildfire, while metal gutters hold up. Add gutter guards so leaves and needles can’t pile up. Keep trim noncombustible, too. IBHS also suggests keeping 6 inches of noncombustible siding above the ground. 
5. A clear “zero zone” (0 to 5 feet). Put gravel or concrete around the full perimeter. No bark mulch. No stacked firewood. No wood fence touching the wall. IBHS’s research points to a five-foot noncombustible zone, including fences, as part of the perimeter. Colorado’s state forestry guidance calls this area Zone 1, and California’s version is Zone 0. The idea is the same .
6. Smart siting and defensible-space landscaping. Place the building away from heavy brush and steep slopes if you can. Space it from your home and other structures. Then manage vegetation out to 100 feet, or to your property line in California. In Colorado, the zones apply around every building on your property, including detached garages, storage buildings, and barns. 

A Building Is a System

Here’s the point of the whole list. Steel doesn’t burn. But a steel building with an open vent, a plastic skylight, or a woodpile against the wall still has a weak link. Embers find the weak link in the chain .

So the details matter as much as the steel. If you can only do one thing this week, check your vents and clear that five-foot zone.

Will a Metal Building Help With Wildfire Insurance?

Let’s talk about the question behind the question. You’re not only asking if the building will survive. You’re asking if you’ll still be able to insure it.

Non-renewal letters, higher premiums, and a push toward the FAIR Plan are real worries in both states. We won’t promise a metal building fixes that. But it can help, and both states now have rules that make your mitigation work count.

How Insurers Evaluate Wildfire Risk

Insurers look at your property from a few angles: the building’s materials, the roof’s fire rating, the vents, and the space around it.

California and Colorado both give you more leverage than before.

California. The Safer from Wildfires regulation requires insurers to give discounts for actions like a Class A fire-rated roof, ember- and fire-resistant vents, and defensible space. The FAIR Plan must offer discounts too. The size varies. The regulation doesn’t set the discount amounts. And it isn’t a promise of coverage. It doesn’t guarantee renewal or a specific discount.  

Colorado. The state passed a transparency law. HB25-1182 requires insurers that use wildfire risk models to share your risk score, reflect mitigation in their models or give discounts for documented work, and offer an appeal. It covers private insurers and the Colorado FAIR Plan. Insurers must give you a written risk score within 15 days if you ask. 

Notice what both states reward. Class A roofs. Ember-resistant vents. A clear zone around the building. Those are the items on our checklist.

What to Ask Your Agent Before You Build

Most of these programs were written with homes in mind. A detached shop, barn, or garage may be treated differently. So ask first, before the foundation is poured.

• Will this building be covered? Ask how outbuildings are covered and what the limit is.
• Which features do you credit? Roof class, vents, zero zone, defensible space.
• What proof do you need? Spec sheets, test listings, photos, an inspection?
• What’s my current wildfire risk score? In Colorado, you can request it in writing.
• Will adding this building change my renewal? Get the answer before you commit.

Write down what they say. Then bring that list to us.

An Honest Note

Results vary by carrier and by location. A metal building won’t guarantee a lower premium or save a policy. A strong roof on a property buried in brush still looks risky.

What we can do is give you clear documentation. That means building specs, roof and wall assembly details, and a plan your agent can review. It’s the paper trail insurers ask for.

More Than Fire Protection: What It’s Like to Own a Building That Lasts

Picture a Saturday morning in October. The air is dry and the wind is picking up. You’re not checking the roof or wondering what might blow in. You’re in the shop with a coffee, working on the project you’ve put off all summer.

That’s what a good building gives you. It isn’t just fire protection. It’s one less thing to worry about.

The Spaces You’ll Actually Use

Think about what you’re building for.

• The workshop where you spend your weekends and keep your tools safe.
• The barn that shelters your animals, your hay, and your equipment.
• The garage that keeps a classic car out of the weather.
• The backyard studio or ADU that gives family a place to land.

These aren’t just structures. They hold the things and the people you care about. When everything else feels uncertain, it helps to have one space you trust.

The Practical Perks

Fire resistance is the headline. The everyday benefits are what you’ll notice year after year.

• Durability. Metal roofs can last 40 to 70 years, and they generally outlast asphalt shingles and wood shakes. 
• Low maintenance. They need less upkeep than asphalt or wood. You won’t be re-shingling or repainting every few years. 
• Pest and rot resistance. Steel doesn’t rot, and termites can’t eat it.
• Customization. Sizes, doors, windows, and layouts can be fitted to how you work.
• Faster timelines. Pre-engineered parts usually mean less time on site than a custom-framed building.

One honest caveat. Metal isn’t dent-proof. It can dent in hailstorms. If hail is common where you live, ask about panel gauge and finish. 

What You Can Build With Metal in a Wildfire Zone

Metal works for more than one kind of building. Here’s what we see people build in fire-prone areas, and one wildfire tip for each.

Garages and Workshops

Your tools, vehicles, and projects are all valuable. A steel garage or shop gives you a noncombustible shell around them. Keep the zero zone clear and store fuel cans away from the walls.  Explore metal garages and workshops 

Barns and Equestrian Buildings

Animals and equipment need real protection. Metal barns resist ember ignition better than wood. One note on fuel: hay burns, so store it in a separate building if you can. In Colorado, defensible space zones apply around barns and every other building on your property. Explore metal barns and horse barns  

RV and Equipment Storage

Boats, RVs, and tractors cost a lot to replace. A covered or enclosed steel building keeps embers off them. Seal door gaps so embers can’t drift in.  Explore equipment storage  

ADUs and Backyard Studios

Extra living space is a big draw. Just know the rules are stricter for places people sleep. In Santa Cruz County’s State Responsibility Area, for example, WUI requirements apply to all new structures regardless of use. Expect the same code review as any new building, plus residential requirements for insulation and egress. Check early with your building department.
 

Agricultural and Commercial Buildings

Farms, shops, and storage yards all do well with steel. Some counties, like Mesa County in Colorado, require review or a permit for accessory structures in WUI areas. Ask what your county needs before you design. Explore agricultural and commercial buildings 

How Metal Pro Building Helps You Build With Confidence

Building in a fire zone shouldn’t feel like guesswork. Our job is to be your guide. We’d rather you understand your options than rush into one.

Here’s what that looks like in practice. We help with the site, the code questions, the design, the engineering, and the delivery. You make the calls. We make sure you have the facts.

How It Works

1. Talk it through. Tell us what you want to build and where. We ask about your parcel, your zone, and your concerns.
2. Design for your site and zone. We match the building to your location. That includes fire-hazard zone, wind, snow, and the ember-resistant details covered in the checklist above.
3. Engineering and permitting support. We help you understand what your county will ask for. In California, that’s the WUI Code. In Colorado, it’s the Wildfire Resiliency Code and any local changes.
4. Clean, efficient installation. The building is delivered and set up with as little disruption as possible.
5. Peace of mind. You get documentation you can hand to your insurer, and a building built to last.

Not Sure What Your Property Needs?

That’s a normal place to start. Wildfire rules vary by state, by county, and sometimes by street.

Talk with a building specialist. No pressure, just straight answers. Request a free consultation →

Frequently Asked Questions

Build Smart, and Sleep Better

You can’t control fire season. You can control what you build.

Metal gives you a strong start. It doesn’t burn, and it leaves embers little to hold onto. Add ember-resistant vents, a clear zero zone, and real defensible space, and you have a solid defense. The details matter as much as the steel.

If you’re planning a shop, barn, garage, or ADU in a fire-prone area, you don’t have to figure it out alone. Request a free consultation or quote, or see what we offer in California and Colorado.