Window, door & siding replacement in Los Altos Hills, CA

Custom Exteriors replaces windows, entry doors, patio doors, and siding for Los Altos Hills homeowners, with fire resistance built into the product choices. We install Infinity from Marvin fiberglass windows, James Hardie fiber cement siding, and ProVia and Therma-Tru entry doors, using our own full-time AAMA Certified Master Installers, not subcontractors.

Why Los Altos Hills homes need a different approach

Los Altos Hills homes sit on large, often hillside lots next to open space, so exterior upgrades here have to account for wildfire exposure as well as comfort and appearance. The Town incorporated in 1956 to protect its rural, residential character. Today about 8,000 residents live across nine square miles, with no commercial district and an 80-mile network of community pathways.

Lots are large, with a one-acre minimum, and the housing stock spans nearly a century. It includes early twentieth-century summer estates, midcentury ranch homes, and modern estates built in the last few years. Many homes exceed 4,000 square feet and have far more glass than a typical suburban house.

With average home values above $6 million, homeowners here expect a replacement that fits the architecture and holds up for decades. Custom Exteriors has completed 30,000+ projects over 29 years with Infinity from Marvin, James Hardie, and ProVia and Therma-Tru products, exclusively. We do not install vinyl or builder-grade alternatives.

Wildfire considerations for Los Altos Hills homeowners

Wildfire risk is part of owning a home in Los Altos Hills, and the Town's own map makes it specific to your address. In May 2025, the Town Council adopted a local Fire Hazard Severity Zone map that classifies about 507 properties as Very High fire hazard. You can look up your property on the Town's map or the CAL FIRE Fire Hazard Severity Zone viewer.

New homes built in fire hazard zones must meet California's wildfire building standards. For windows, that means multipane glass with at least one tempered pane. For siding, it means noncombustible or ignition-resistant material. Replacing windows or siding on an existing home generally does not trigger those rules, but many homeowners choose to meet the same standard anyway.

That is where product choice matters:

Windows: Infinity from Marvin windows are available with tempered glass options, and our design consultants can specify glass packages that match the standard new homes must meet.
Siding: James Hardie fiber cement siding is noncombustible. Learn more about fire-resistant siding.
Roofing: The Town already requires Class A fire-rated roofing on all roofs, so upgrading windows and siding closes the other gaps in the exterior.

Replacement windows and patio doors

Infinity from Marvin fiberglass windows suit Los Altos Hills homes because fiberglass stays stable through sun, heat, and cool nights on exposed hillside lots. Fiberglass expands and contracts at nearly the same rate as glass, so the seal between frame and glass holds up longer than vinyl typically does. See our fiberglass versus vinyl comparison for the details.

Homes here often have large, view-facing glass and several distinct architectural styles on the same street. Common projects include:

View windows: Large picture windows and window walls sized to preserve views of the hills and the valley.
Ranch homes: Casement and double-hung windows that replace original aluminum or wood frames without changing the home's look.
Estate homes: Divided-lite patterns and trim profiles matched to the original construction.
Indoor-outdoor living: Sliding, French, and bi-fold patio doors that open onto large yards and terraces.

We choose retrofit, block frame, or new construction installation based on the condition of your frames and exterior. Our window installation methods guide explains each one. As an Infinity from Marvin Platinum Partner, Marvin's highest certification tier for Infinity dealers, we carry full-size displays in our Pleasanton showroom.

Entry door replacement

On a Los Altos Hills estate, the entry door sets the tone for the whole facade, and it is one of the easiest exterior upgrades to complete on its own. ProVia and Therma-Tru entry doors come in fiberglass and steel, with glass, hardware, and finish options for everything from a midcentury ranch to a traditional estate.

Fiberglass and steel doors also resist warping and weathering better than many original wood doors on sun-exposed hillside lots. Our design consultants help you choose the style, glass, and hardware so the door fits the house.

James Hardie fiber cement siding

James Hardie fiber cement siding is the siding we recommend for Los Altos Hills because it is noncombustible, the same class of material the state requires on new homes in fire hazard zones. It also resists moisture, pests, and rot, which matters on homes surrounded by trees and landscaping.

ColorPlus Technology, James Hardie's factory-applied finish, is baked on under controlled conditions, so it holds color longer than siding painted on site and needs far less repainting on large homes. The siding is backed by a 30-year non-prorated product warranty and a 15-year ColorPlus finish warranty. We install James Hardie exclusively because after 29 years of evaluating siding, it is what we would put on our own homes.

If you are replacing siding, it is the right time to replace windows too, using new construction installation while the exterior is open.

Why Los Altos Hills homeowners choose Custom Exteriors

Los Altos Hills homeowners hire Custom Exteriors for accountability they can verify before they sign:

Full-time installers, not subcontractors. Our installation team are Custom Exteriors employees, many with more than a decade on our crew.
AAMA Certified Master Installers (American Architectural Manufacturers Association), trained to the installation standards manufacturers require to honor their warranties.
Permit handling. We manage the Town of Los Altos Hills permit and inspection process for you.
Older-home experience. We are EPA Lead-Safe Renovation, Repair, and Painting (RRP) Certified for homes built before 1978.
Third-party recognition and warranty coverage. Diamond Certified and BBB Accredited. See our awards, reviews, and product and labor warranty.

Frequently asked questions

Q: Do I need a permit to replace windows in Los Altos Hills?A: Yes. The Town of Los Altos Hills lists window replacement among the projects that require a building permit. Custom Exteriors handles the permit application and inspections with the Town as part of your project.

Q: My home is in a Very High Fire Hazard Severity Zone. Do my replacement windows have to be tempered?A: Generally, no. California's wildfire building standards, including multipane glass with at least one tempered pane, apply to new homes in fire hazard zones, and replacements on existing homes are typically exempt. Many homeowners choose tempered glass anyway, because it meets the same standard new homes must meet. We can confirm the requirements for your property during the consultation.

Q: How much does window replacement cost in Los Altos Hills, CA?A: Cost depends on the number and size of your windows, the glass package, the products you choose, and the installation method. Large-format view windows and tempered glass add cost compared with standard sizes. Review our window pricing factors and window cost guide before your consultation. We provide free, itemized estimates so you know what you are paying for before you decide.

Q: Is James Hardie siding a good choice for a home near open space?A: Yes. James Hardie fiber cement siding is noncombustible, which is the kind of material California requires on new homes in fire hazard zones. It also resists moisture and rot and needs far less maintenance than wood siding.

Q: My Los Altos Hills home was built before 1978. Does that change the project?A: It can. Homes built before 1978 may contain lead-based paint, and federal law requires lead-safe work practices on renovations that disturb painted surfaces in those homes. Custom Exteriors is EPA Lead-Safe Renovation, Repair, and Painting (RRP) Certified, and we confirm whether lead-safe procedures apply before installation begins.

Q: Do I have to visit the Pleasanton showroom to get an estimate?A: No. We offer free, no-pressure in-home consultations throughout Los Altos Hills. The showroom is there if you want to see and handle full-size window, door, and siding displays first.

Ready to upgrade your Los Altos Hills home's windows, siding, or doors?

Schedule a free, no-pressure consultation and we will walk through your home, your fire hazard zone, your options, and an itemized estimate, with no obligation. Prefer to see the products first? Our Pleasanton showroom has full-size displays of every window, door, and siding product we install.

Convenient financing options

We offer 18 months zero payments and zero interest, or 4.99% financing on approved credit. Financing is a tool to make a project more accessible, not the reason to choose us. Bring it up during your consultation if you would like to discuss options.

Schedule a Consultation | Visit Our Showroom | Explore Financing Options

Nearby areas we also serve

Custom Exteriors also serves Los Altos, Cupertino, Saratoga, Mountain View and Sunnyvale, San Jose, and Palo Alto, along with Pleasanton, Dublin, Livermore, San Ramon, Danville, and the greater East Bay. See the full service area list for every city we cover.

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