If the back bedrooms cook on an August afternoon and the front rooms feel drafty by December, the windows are usually the reason. A lot of Martinez homes — especially the older stock in and around the historic downtown, but plenty of postwar tract houses too — still carry original single-pane windows with no Low-E coating. In a climate with genuinely hot, dry summers and cool, damp winters, that single pane is the weak point in the wall for both comfort and energy. Bay Area Siding Company, a Marin-based (Larkspur) siding and window contractor, replaces them properly: measured, spec'd to code, flashed, air-sealed, and finished.

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

The comfort problem in older Martinez homes

Single-pane glass does two things badly. In summer it lets heat pour in through the sunny elevations, so the rooms facing the afternoon sun never quite cool down. In winter it radiates warmth back out and invites condensation. The symptoms are familiar:

• Rooms on the west and south sides that stay hot long after sunset
• Drafts and cold spots near the glass even with the window shut and locked
• Fog trapped between the panes on a dual-pane unit — a failed seal that can't be repaired, only replaced
• Sashes that stick, won't stay up, or won't latch — swollen wood, paint-sealed frames, or worn balances
• Rot, soft frames, or staining at the sill

A modern dual-pane, Low-E unit closes that gap, and on an older Martinez home the improvement in day-to-day comfort is the part people notice first.

Three decisions that shape the result

Most of a good window project comes down to getting three choices right:

1. The glass package. Dual-pane insulated glass with a Low-E coating is the baseline. California's Title 24 energy code sets maximum U-factor and SHGC values for replacement windows, and those targets vary by climate zone and change across code cycles — so rather than quote a fixed number, we confirm the values in effect at permit time and spec the glass to meet them. For Martinez's sun exposure, the SHGC (how much solar heat the glass lets through) is worth paying attention to.
2. The frame material. Vinyl, fiberglass, aluminum-clad wood, and aluminum each balance cost, thermal performance, and looks differently. An older character home near downtown often looks right with clad-wood or a profile that respects the original opening; a tract house has more latitude.
3. Retrofit vs. new-construction install. A retrofit (insert) keeps the existing frame and is less invasive. A new-construction (full-frame) install removes the window down to the rough opening so the flashing can be fully renewed — the right call where there's rot or past water intrusion. We do both and recommend based on what the openings show.

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

Permits and energy compliance in Martinez

Window replacement in Martinez is permitted through the City of Martinez Building Division (525 Henrietta Street), which reviews under the currently adopted California Building Standards Codes. Because replacing windows is treated as an alteration under the state Energy Code, a Title 24 energy-compliance document is typically part of the submittal. We prepare the paperwork and confirm the current requirements with the Division rather than assuming last cycle's numbers still apply.

Fire-zone glazing on hillside and valley-edge parcels

This applies to some Martinez addresses, not all. Cal Fire's 2025 local Fire Hazard Severity Zone maps place parts of the city's hillsides and rural Alhambra Valley edges in hazard zones. Where a parcel is in a High or Very High zone and an opening is altered, California Building Code Chapter 7A can require multi-pane glazing with at least one tempered pane, among other measures — and the requirement attaches to the specific altered openings and assemblies, not automatically to the whole house. Whether it applies depends on your parcel's designation and whether the work is classed as a repair or an alteration, so we confirm the designation before ordering glass.

What the install looks like

Short version: we measure each opening precisely, help you settle glass and frame choices, pull the permit, remove the old units and inspect the openings for rot, set the new windows level and plumb, flash and air-seal against water and air, then trim, caulk, test operation, and clean up with a final walkthrough. Nothing about that changes with the phase of the moon — it changes with what the openings reveal, which is why measuring comes first.

Cost factors

We don't post prices because every home is different. What actually drives the number: how many openings and how large, frame material and brand, retrofit vs. new-construction, whether fire-zone tempered/multi-pane glazing is required for the parcel, how much rot repair the openings need, and access — upper-story and hillside openings take more setup.

FAQ

Do I need a permit to replace windows in Martinez? Yes. Window replacement goes through the City of Martinez Building Division, and because it's treated as an alteration under the Energy Code, a Title 24 compliance form is generally part of the submittal. We handle it.

Will new windows really make the hot rooms more comfortable? On an older single-pane home, noticeably. Dual-pane Low-E glass cuts the solar heat gain that overheats sun-facing rooms in summer and the heat loss that chills them in winter — the comfort change is usually the first thing homeowners mention.

I'm on a hillside or out toward Alhambra Valley — do my windows need tempered glass? Possibly, if the parcel is in a fire-hazard zone and the opening is altered. Chapter 7A can require multi-pane glazing with at least one tempered pane on altered openings in those areas. It depends on your parcel and scope, which we confirm before ordering.

Can I keep the look of an older Martinez home? Yes. Frame material and profile can be matched to the original openings — clad-wood and certain vinyl or aluminum profiles all work depending on the house.

Schedule your Martinez window project

Get your windows measured, spec'd to current code, and installed right the first time. Doing the exterior too? See Martinez siding replacement and James Hardie siding, browse the project gallery, or explore the wider Contra Costa service area. Call (415) 619-5167 or request an estimate.