Bay Area Siding Company replaces windows for Cupertino homeowners — the aluminum-frame single-panes still hanging on in ranch and tract houses, the original units in the Eichler tracts, and everything since. We're a Larkspur (Marin) siding and window contractor, and window work is its own discipline: getting the glass package right for the valley's climate, choosing a frame that fits the home, and installing so the opening is sealed and flashed for the long haul.

Ready to start? Request an estimate or call (415) 619-5167.

Three decisions do most of the work

Window shopping gets simpler once you know the levers that actually matter:

1. The glass package. For the South Bay, the win is dual-pane insulated glass with a Low-E coating — it cuts the summer heat gain that makes west- and south-facing Cupertino rooms uncomfortable by mid-afternoon, and it holds warmth on cool winter nights. California's Title 24 energy code caps the U-factor and SHGC allowed for replacement windows, and those limits shift by climate zone and by code cycle, so the right move is to spec to the numbers in force at permit time rather than to a figure you read once. We confirm the current values as part of the job.

2. The frame. Vinyl, fiberglass, aluminum-clad wood, and aluminum each land differently on cost, thermal performance, and looks. A postwar ranch or Eichler with clean, spare lines often reads best with a slim profile that doesn't fatten the sightlines; a home with wood trim may call for clad-wood. This is worth matching to the house rather than defaulting.

3. Retrofit or new-construction install. A retrofit (insert) install keeps the existing frame and is the less invasive path when the surrounding wall is sound. A new-construction (full-frame) install takes the unit back to the rough opening so the flashing and WRB integration can be fully renewed — the right call where there's rot, past leakage, or a frame that's failing. We do both and recommend based on what the openings actually show.

Comparing brands

We install a range of lines so the window can be matched to the home and the budget, not the other way around. Start at our window hub, then dig into the ones you're weighing:

• Anlin — California-made vinyl, built around this state's climate
• Milgard — a West Coast mainstay across vinyl and fiberglass
• Andersen — wood and composite lines
• Marvin — wood and clad-wood, strong on larger and custom openings
• Pella — a broad range across materials

We install aluminum windows as well where the look or the opening calls for it.

Permitting and Title 24 in Cupertino

Here's a Cupertino wrinkle worth knowing up front: the City offers an instant online permit for some exterior work — siding re-side, like-for-like re-roof — but window replacement is not on that instant list, so it runs as a standard permit. Because swapping windows is an alteration under the Energy Code, a Title 24 fenestration compliance form is part of what gets submitted. None of that should slow you down — we prepare the submittal and pull the permit — but it's why a window project is worth scheduling with the permit timeline in mind. The City's baseline rule is simple: if the work isn't on the exempt list, a permit is required, and the Building Division handles residential fenestration.

If your parcel touches the foothills

Most Cupertino homes are on the flat valley floor, where the window conversation is purely about energy, comfort, and fit. But the city's western edge runs up toward the Santa Cruz Mountains, and CAL FIRE's 2025 fire-hazard maps expanded the areas of Cupertino designated moderate, high, and very high fire hazard well beyond the old boundaries. In a designated fire-hazard zone, exterior glazing falls under the state's fire-hardening provisions — which can mean multi-pane units with a tempered pane for altered openings — but exactly what applies turns on your parcel's designation and whether the work is a repair or an alteration. We check the parcel against the City's fire-hazard lookup before ordering glass, so nothing gets specced twice. On the valley floor it's simply not part of the equation.

What the job costs comes down to

We don't post prices, because the number is built from your openings: how many windows and how big; the frame material and brand; retrofit versus full-frame; whether any openings turn up rot that adds scope once they're out; whether fire-zone tempered/multi-pane glazing applies; and access, since upper-story or hillside openings need more setup. A measured walkthrough is how we turn that into a real quote.

FAQ

Do I need a permit to replace windows in Cupertino? Yes. Unlike siding, window replacement isn't eligible for the City's instant online permit, so it goes through a standard permit, and a Title 24 energy compliance form is part of the submittal. We handle the permitting.

How energy-efficient do my windows have to be? They have to meet Title 24's limits for replacement fenestration, and those depend on the climate zone and the code cycle in effect when you permit. Rather than quote a fixed number that may be out of date, we confirm the current U-factor and SHGC requirements at permit time and spec to them.

My property is near the foothills — will my windows need tempered glass? Possibly. In a designated fire-hazard zone, altered openings can require multi-pane glazing with at least one tempered pane under the state's fire provisions. Whether it reaches your project depends on your parcel's designation and whether the work is a repair or an alteration — we confirm before ordering.

Retrofit or full-frame — which is right for my house? Retrofit keeps the existing frame and is less invasive when the wall around the opening is sound. Full-frame goes back to the rough opening to renew flashing and is the better choice where there's rot or past water intrusion. We assess each opening and recommend.

Get your Cupertino windows handled

Sized, specced to code, and flashed to keep water out — done once, done right. Request an estimate or call (415) 619-5167.

Also weighing the exterior walls? We do James Hardie siding and siding replacement in Cupertino, serve the wider South Bay, and keep finished jobs in our project gallery.