The reason a lot of people move to Moraga is the view — wooded ridgelines, oak-covered hills, and open space out most of the back windows. That's also why window replacement here is rarely just an energy upgrade. A Moraga home usually has a few large view openings doing real work in the living space, and getting those right — the glass, the sightlines, the way the frame sits in a hillside wall — is the difference between a window you notice and one that disappears into the view. Bay Area Siding Company is a Marin-based siding and window contractor, and we handle Moraga window projects from the field measure through flashing and the final walkthrough.

Ready to talk windows? Call (415) 619-5167.

View glass, comfort, and the two things worth deciding first

On a Moraga home, the big glass is often the oldest and least efficient part of the envelope — original single-pane picture windows and sliders that leak heat on hot inland afternoons and feel cold against a shaded canyon in winter. Two decisions carry most of the outcome:

• The glass package. Dual-pane insulated glass with a Low-E coating is the baseline. On large west- and south-facing view openings, the coating choice matters more than usual — it's what keeps a wall of afternoon glass from cooking the room while still letting the view read clearly. California's Title 24 energy code sets the performance a replacement window has to hit, and the required numbers depend on the climate zone and the code cycle in effect, so we confirm the current targets at permit time rather than quoting a fixed figure.
• The frame. Vinyl, fiberglass, aluminum-clad wood, and aluminum each trade cost, thermal performance, and appearance differently. On a mid-century or ranch home with clean lines, a slim profile that keeps the glass area generous is usually what you want; heavier traditional homes may call for clad-wood.

Fire-zone glazing on the hills

Much of Moraga — the eastern and northeastern hills and parcels backing onto open space — falls within mapped fire hazard severity zones under the updated 2025 Cal Fire maps administered locally by the Moraga-Orinda Fire District. Where a parcel carries a fire-hazard designation, California Building Code Chapter 7A can govern exterior glazing on regulated openings, generally calling for multi-paned units with at least one tempered pane, among other requirements. Whether it applies to your project turns on your parcel's designation and on whether the work is treated as a repair or a regulated alteration — a genuinely nuanced call, and one we confirm with the Town and the fire district as part of scoping rather than assume. If your home is on or near the hills, flag it early; it can shape the glass order.

Permits in Moraga

Replacing windows in Moraga requires a building permit — the Town runs permit review, inspection, and code enforcement through the Contra Costa County Department of Conservation and Development. There's a useful distinction on the planning side: windows can generally be replaced without separate Town Planning Department approval as long as the openings aren't enlarged more than about 10% and no new windows are added; change the size or add openings and Planning review comes into play. A building permit is still needed either way, and we handle the application and coordination.

Retrofit vs. new-construction install

Two ways to set a replacement window, and the right one depends on the opening:

• Retrofit (insert): the existing frame stays and the new unit sets into it. Less invasive, faster, and a good fit where the surrounding wall and flashing are sound.
• New-construction (full-frame): the unit comes out to the rough opening so the flashing and water-resistive barrier can be fully renewed. This is the right call where there's rot, water intrusion, or you're re-siding at the same time and want the whole detail redone.

We do both, and we'll tell you honestly which one an opening actually needs after we look at it.

Comparing brands

We install and can compare the major lines for you: Anlin, Milgard, Andersen, Marvin, and Pella, plus aluminum. Start from the window replacement hub for the overview, then dig into the line that fits your home and budget.

What affects the cost

Every job is priced individually. The drivers: the number and size of openings — large view glass costs more than a standard bedroom window; frame material and brand; retrofit vs. new-construction; whether fire-zone tempered or multi-pane glazing is required on your parcel; the condition of the framing behind the trim (rot repair adds scope); and access, since upper-story and hillside openings take more setup.

FAQ

Do I need a permit to replace windows in Moraga? Yes — a building permit is required. Moraga handles permit review and inspection through the Contra Costa County Department of Conservation and Development. Separate Town Planning approval generally isn't needed if you keep the openings close to their existing size (within about 10%) and don't add windows. We handle the permit.

My home is on the hills / near open space — do my windows need to be tempered? Possibly. On parcels with a fire-hazard designation, Chapter 7A can require multi-paned glazing with at least one tempered pane on regulated openings when work is treated as an alteration. It depends on your parcel and how the scope is classified, which we confirm before ordering.

Can I keep the view and still improve efficiency? That's the usual goal in Moraga, and yes — a modern dual-pane Low-E unit in a slim frame keeps the glass area and the sightline while cutting the heat gain and drafts of an old single-pane window.

Retrofit or new-construction — which do I need? Retrofit is less invasive and keeps the existing frame; new-construction removes the unit to the rough opening so flashing can be fully renewed, which is the right choice where there's rot or you're re-siding at the same time. We assess and recommend.

Get started

We're based in Larkspur and serve Moraga and the wider Contra Costa area. See finished work in our project gallery, and if the exterior is on your list too, we also handle Moraga siding replacement and James Hardie siding. Call Bay Area Siding Company at (415) 619-5167 or request an estimate.