Fire-resistant James Hardie siding in Orinda, CA

Custom Exteriors replaces siding on Orinda homes with James Hardie fiber cement, a noncombustible siding suited to one of the highest fire hazard areas in the East Bay. Our own full-time crews install it, not subcontractors. James Hardie siding also resists rot, moisture, and pests, and carries a 30-year non-prorated product warranty. We have served Orinda and the Lamorinda area from our Pleasanton showroom since 1997, with 30,000+ completed projects.

Orinda's wildfire hazard, by the numbers

Most of Orinda is mapped as a Very High Fire Hazard Severity Zone, which makes siding one of the most important choices you can make for your home's exterior. Under the State Fire Marshal's 2025 maps, Orinda has more than 5,200 acres rated Very High, the most of any city in Contra Costa County. That is more than double the 2,424 acres mapped in 2011.

The Moraga-Orinda Fire District adopted the 2025 map on May 21, 2025, and it applies throughout the City of Orinda. The map also includes High and Moderate zones, so check your own address on MOFD's website or the State Fire Marshal's Fire Hazard Severity Zone viewer.

What that means for Orinda homeowners:

Defensible space. Homes in Very High zones must maintain 100 feet of defensible space.
Zone Zero. State rules for the ember-resistant area within 5 feet of the home are expected to apply in Orinda's Very High zones. Check with MOFD for current requirements.
Building requirements. Wildfire construction standards may apply to exterior wall materials when you replace siding. More on that below.

The map measures hazard, not your home's individual risk. The materials on your home's exterior are one of the things you can control.

How James Hardie siding performs in a fire

James Hardie fiber cement siding does not burn. It is made mostly of cement, sand, and cellulose fibers, and it is classified as noncombustible when tested to ASTM E136. Wood siding and wood shakes cannot make that claim.

Here is what that means for an Orinda home:

Noncombustible cladding. James Hardie siding will not ignite or add fuel when exposed to flame or wind-blown embers.
Class A flame spread. James Hardie siding has a Class A fire rating when tested to ASTM E84, the highest class in that test.
State Fire Marshal listed. HardiePlank, HardiePanel, and HardieShingle siding have been listed by the California State Fire Marshal for use in wildland-urban interface construction.
A clear path through the code. California's wildfire construction standards accept noncombustible material as a compliant exterior wall covering. Fiber cement meets that on its own, without special assemblies or treatments.

Siding is one part of a fire-resistant home, not the whole answer. Wildfire research consistently points to embers entering through vents, eaves, and windows, and to combustible material near the house, as major causes of home ignition. That is why we also recommend:

Boxed eaves with HardieSoffit panels, which use the same noncombustible fiber cement on the underside of your roofline.
HardieTrim boards around windows, doors, and corners instead of wood trim.
Dual-pane windows with tempered glass, which are more resistant to breaking from heat.
A noncombustible zone right next to the house, free of bark mulch, wood piles, and dry plants.‍

Learn more about James Hardie siding

Wildfire building codes in Orinda

California's wildfire construction rules now live in their own code. As of January 1, 2026, the state moved those standards out of Chapter 7A of the Building Code into the new California Wildland-Urban Interface Code. The Moraga-Orinda Fire District adopted that code with local amendments, and the Orinda City Council ratified it in March 2026.

Whether those standards apply to your siding project depends on your zone and the scope of work, and the building department makes that call. We confirm what applies during permitting and specify materials that meet it. Because James Hardie siding is noncombustible, it meets the exterior wall covering requirement without extra steps.

Why Orinda homes are ready for new siding

Many Orinda homes sit on wooded hillside lots, and their original wood siding takes a beating from the setting. Shade, irrigation, and tree cover keep lower courses damp. Sun bakes exposed walls. Woodpeckers and insects work on boards near oaks and open space.

At the same time, wood siding near brush and trees is a fuel source in a wildfire. Replacing it with noncombustible fiber cement addresses both problems at once.

When we remove old siding, we inspect the sheathing underneath and repair damaged sections before the new siding goes on. Many older homes also have lead paint. We are EPA Lead-Safe RRP Certified and follow lead-safe work practices during removal.

Siding styles for Orinda homes

James Hardie offers profiles that suit Orinda's traditional, ranch, and custom hillside homes, all with the same noncombustible performance.

HardieShingle siding gives you the cedar shake look many Orinda homes are known for, without the fire exposure of real wood shakes.
HardiePlank lap siding for the classic horizontal look on ranch and traditional homes.
HardiePanel vertical siding for a board and batten look on modern and farmhouse-style homes.
Hardie Artisan siding for a thicker profile and deeper shadow lines on custom homes.

ColorPlus Technology, James Hardie's factory-baked finish, holds color longer than paint applied on site and is backed by a 15-year limited finish warranty. Our East Bay siding color guide and full-size displays in our Pleasanton showroom help you choose.

Permits in Orinda

Siding replacement in Orinda usually needs a building permit, and Custom Exteriors handles it for you. The process has two steps: the City of Orinda Planning Department reviews the project first, then Contra Costa County issues the building permit and performs inspections.

If your neighborhood has an HOA, check its architectural review rules early. We provide product specifications and color samples for your application.

Replacing siding and windows together

If your windows are also near the end of their life, replacing both at once gives you a better result. With the siding off, we can install new windows using the new construction method, so each opening is fully flashed and sealed. It also lets you upgrade the whole wall, siding, trim, and windows, at the same time.

Ask about tempered glass options for wildfire exposure. See our Orinda windows page for the Infinity by Marvin fiberglass windows we install.

Why Orinda homeowners choose Custom Exteriors

Orinda homeowners hire us because they can verify who does the work and who stands behind it.

Full-time employee installers, not subcontractors. The crew that installs your siding works for Custom Exteriors. Here is why that matters.
Local since 1997. We have served Lamorinda and the East Bay from Pleasanton for nearly three decades, with 30,000+ completed projects.
Permits and inspections handled, including the City planning review, the County permit, and any wildfire code requirements for your project.
Third-party recognition. Diamond Certified and BBB Accredited. See our awards and reviews.
Warranty coverage. James Hardie's product warranties plus our own product and labor warranty.

Frequently asked questions

Q: Is James Hardie siding fireproof? A: No siding is fireproof, but James Hardie siding is noncombustible. It is classified as noncombustible when tested to ASTM E136 and has a Class A flame spread rating under ASTM E84, so it will not ignite or add fuel to a fire. A home's overall fire resistance also depends on its roof, vents, eaves, windows, and the area around the house.

Q: Is my Orinda home in a Very High fire hazard zone? A: Most of Orinda is. The 2025 map adopted by the Moraga-Orinda Fire District rates more than 5,200 acres of Orinda as Very High, with additional High and Moderate areas. Check your address on MOFD's website or the State Fire Marshal's Fire Hazard Severity Zone viewer.

Q: Do wildfire building codes apply to replacing my siding? A: They may, depending on your zone and the scope of your project. California's wildfire construction rules moved into the new California Wildland-Urban Interface Code on January 1, 2026, and MOFD adopted it with local amendments. The building department decides what applies. James Hardie siding is noncombustible, so it meets the exterior wall covering requirement. We confirm what applies during permitting.

Q: Will fire-resistant siding lower my homeowners insurance? A: We cannot promise that, because insurers set their own pricing and discounts. Ask your insurer which home hardening measures it recognizes. We provide product documentation for the James Hardie siding we install if your insurer asks for it.

Q: Do I need a permit to replace siding in Orinda? A: In most cases, yes. The City of Orinda Planning Department reviews the project first, then Contra Costa County issues the building permit and handles inspections. Custom Exteriors manages both steps for you.

Q: Can I get the look of cedar shakes without the fire risk? A: Yes. HardieShingle siding recreates the look of cedar shakes in noncombustible fiber cement. It is a common choice for homeowners who want to keep a traditional look while replacing wood shakes.

Q: How much does James Hardie siding cost in Orinda? A: Cost depends on the size of your home, how much old siding has to come off, the condition of the wall underneath, the profile and finish you choose, and how much trim and soffit is involved. Hillside access and two-story walls typically add cost. See our siding pricing guide for the main factors. We provide free, itemized estimates so you know exactly what you are paying for.

Ready to replace the siding on your Orinda home?

Schedule a free, no-pressure consultation. We will look at your current siding, check for damage underneath, walk through profiles, colors, and fire-resistant options, and give you an itemized estimate, with no obligation. Prefer to see the products first? Our Pleasanton showroom has full-size James Hardie displays.‍

‍Visit our Pleasanton showroom (2142 Rheem Drive, Suite E, Pleasanton, CA 94588) Phone: (925) 249-2280

Financing options

We offer 18 months with no payments and no interest if the balance is paid in full within the promotional period, or 4.99% financing on approved credit. Ask about options during your consultation.

See financing details

Nearby areas we also serve

Custom Exteriors also installs James Hardie siding in Lafayette, Walnut Creek, and Oakland, and serves nearby Moraga and Berkeley. See everything we offer in Orinda, or view our full service area list.