A large share of San Anselmo's homes were built before 1940, which means a lot of original single-pane wood windows are still in service in the town's Craftsman bungalows, Tudor cottages, and shingle-style houses. In a cool, damp valley with wet winters, those old sashes are where comfort and energy quietly leak away. Bay Area Siding Company is a Larkspur-based siding and window contractor, and we install replacement windows for San Anselmo homeowners end to end: measuring, glass and frame selection, permitting, removal, flashing and air-sealing, and the final walkthrough.

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

Signs your windows are due

Old windows tend to tell on themselves. Watch for:

• Drafts and cold glass in winter even with everything shut — single panes have almost no insulating value
• Fog or moisture trapped between the panes on a dual-pane unit, a failed seal that can't be repaired
• Sashes that stick, drop, or won't latch — swollen wood, painted-shut frames, or worn balances, common in the valley's humidity
• Interior condensation pooling on sills through damp winter mornings
• Soft, stained, or rotting sills and surrounds, especially on shaded elevations

If a couple of these ring true across the house, replacement usually beats another round of repairs.

Choosing the right replacement window

Three decisions carry most of the weight:

• Energy and comfort. Dual-pane insulated glass with a Low-E coating is the baseline for a cool, damp climate — it cuts drafts, dampens condensation, and holds warmth on gray winter days. California's Title 24 energy code sets maximum U-factor and SHGC values for replacement windows, and those numbers vary by climate zone and code cycle, so we confirm the current requirement at permit time rather than quoting a fixed figure.
• Frame material. Vinyl, fiberglass, aluminum-clad wood, and aluminum each balance cost, thermal performance, and appearance differently. On San Anselmo's period homes, clad-wood or a frame profile that respects the original opening often looks right where a bulky retrofit would not.
• Retrofit vs. new-construction install. A retrofit (insert) keeps the existing frame and is less disruptive; a new-construction install takes the opening down to the framing so the flashing can be fully renewed — the better route where there's rot or past water intrusion, which older shaded walls here often hide. We do both.

Comparing brands? Start at our window replacement hub, then read the specifics for Anlin, Milgard, Andersen, Marvin, and Pella. We also install aluminum windows.

What to expect: our process

1. Consultation — we look at your existing windows, openings, and what you want to fix.
2. Measure — precise field measurements for every opening.
3. Product and energy selection — glass package, frame, and finish chosen to meet the Title 24 requirement in effect.
4. Permit — window replacement in San Anselmo is generally permitted work through the Town's Building Division; we confirm and pull it.
5. Removal and prep — old units out, openings inspected for rot or water damage.
6. Install, flashing, and air-seal — set level and plumb, then flashed and sealed against water and air, which matters in this wet-winter climate.
7. Finish and walkthrough — trim, caulk, an operation check, and cleanup with you.

San Anselmo-specific things to know

Permits and Title 24. Window replacement is handled by the Town of San Anselmo's Building Division and generally requires a building permit. Because California treats replacement windows as an energy-code matter, a Title 24 fenestration compliance form is typically part of the submittal. The exact U-factor/SHGC targets depend on the climate zone and current code, so we confirm them at permit time and choose units that comply — we handle the paperwork.

Period homes and matching the look. In the Yolanda District, Winship Park, and the cottage blocks around downtown, the streetscape's period character is part of the home's value. Frame material and sightlines can be matched so a Craftsman or Tudor keeps its proportions — clad-wood and certain vinyl and aluminum profiles all work depending on the house.

The hillsides. Homes on the wooded slopes — Seminary Hill, Bald Hill, near Sleepy Hollow — sit in terrain with wildfire exposure, and Cal Fire has been updating Fire Hazard Severity Zones for local-responsibility areas across the Ross Valley. Where fire-zone building provisions apply, altered openings can call for multi-pane glazing with a tempered pane, but whether that applies to your project depends on the parcel's designation and scope — Ross Valley Fire and the Town confirm it, and we build that check into scoping.

The creek flats. If your home is on the lower flats near San Anselmo Creek, the damp and periodic flood history make water-tight flashing and air-sealing around each opening especially important; we detail those carefully.

Thinking about the whole exterior? We also handle siding replacement and James Hardie fiber cement in San Anselmo, and we serve the wider Marin area. See finished work in our project gallery.

What affects the cost

Prices aren't something we post, because each home is different. The drivers are the number and size of openings, the frame material and brand, retrofit vs. new-construction, whether hillside fire-zone tempered/multi-pane glazing is required, the condition of the existing framing (rot repair adds scope), and access on upper stories or tighter lots. We price it after measuring.

Frequently asked questions

Do I need a permit to replace windows in San Anselmo? Generally yes. The Town of San Anselmo's Building Division permits window replacement, and a Title 24 energy compliance form is typically part of the submittal. We handle the permitting.

Can I keep the look of my older San Anselmo home? Yes. Frame material, profile, and sightlines can be matched to the original openings so a period home keeps its character — we'll recommend what fits a Craftsman, Tudor, or cottage.

I'm on a wooded hillside — do my windows need tempered glass? Possibly. Where fire-zone provisions apply, altered openings can require multi-pane glazing with at least one tempered pane, but that depends on your parcel's designation and scope. Ross Valley Fire and the Town make the call, and we confirm it before ordering.

Retrofit or new-construction — which is right for me? Retrofit is less invasive and keeps the existing frame; new-construction is better where there's rot or water damage and you want the flashing fully renewed. On older shaded walls here that's a common finding, so we assess each opening and recommend.

Get started

Get your windows measured, specced to code, and installed right the first time. Request an estimate or call Bay Area Siding Company at (415) 619-5167.