Bay Area Siding Company replaces windows for San Leandro homeowners — the original wood double-hungs in downtown and Broadmoor bungalows, the aluminum sliders in postwar ranch tracts, and the larger openings on the slopes above Bay-O-Vista. We're a Larkspur-based siding and window contractor covering the East Bay, and we run the full job: field measuring, glazing and energy selection, permitting, removal, flashing and air-sealing, and a final walkthrough. San Leandro publishes its own window and door guidelines, and we install to them so the work passes and stays on the record.

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

Signs your windows are due

Old windows tend to tell on themselves. Any of these usually means replacement rather than another repair:

• Air you can feel at the edges of the sash even when it's latched shut
• Fog or moisture trapped between the panes — a blown seal on a dual-pane unit, which can only be replaced, not repaired
• Sashes that stick, drop, or won't lock — swollen wood, paint-sealed frames, or spent balances
• Heating and cooling bills running high behind single-pane glass with no Low-E coating
• Soft frames, rot, or water staining at the sill or surround

Two or more of these and you're usually spending good money maintaining a window that's better replaced.

What to look for in a replacement window

Three decisions carry most of the outcome:

• Energy performance. You want dual-pane insulated glass with a Low-E coating. California's Title 24 energy code caps the U-factor (and, for some orientations, solar heat gain) on replacement windows, and San Leandro's window guidelines require your units to carry a compliant Title 24 label. The exact target shifts by climate zone and code cycle, so we confirm the current figure at permit time rather than quoting a number that may be out of date.
• Frame material. Vinyl, fiberglass, aluminum-clad wood, and aluminum each balance cost, thermal performance, and looks differently. San Leandro's older bungalows and cottages with wood detailing often sit best with clad-wood or a profile chosen to respect the original opening; a mid-century ranch may carry a clean vinyl or aluminum line well.
• Retrofit vs. new-construction. A retrofit (insert) keeps the existing frame and is less invasive; a new-construction install strips the opening to the framing so the flashing can be fully renewed — usually the right move where there's rot or past water intrusion. We do both and recommend based on what the openings show.

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

What to expect: our process

1. Consultation — we look at the existing windows, the openings, and your goals.
2. Measure — precise field measurements for each opening.
3. Product & energy selection — glass package, frame, and finish chosen to meet San Leandro's Title 24 label requirement.
4. Permit — we submit through the City of San Leandro Building & Safety Division; most window replacements are issued without plan review.
5. Removal & prep — old units out, openings checked for rot or damage.
6. Install, flashing & air-seal — set level and plumb, flashed and sealed against water and air, with sealing around the frame per the city's guidelines.
7. Finish & walkthrough — trim, caulk, an operation check, and cleanup with you.

San Leandro-specific things to know

The city's window and door guidelines. San Leandro publishes a homeowner-facing window and door guideline document, and it sets out several requirements we build to:

• Energy compliance. Replacement windows must carry a Title 24-compliant U-factor label. We confirm the current maximum with the city at permit time.
• Safety glazing in hazardous locations. The code requires tempered (safety) glazing in specific spots — in and beside doors, near walking surfaces, low glazing close to the floor, and around stairs. We identify which of your openings are "hazardous locations" and spec tempered glass there.
• Bedroom egress. Each sleeping room needs at least one window or door that meets emergency escape-and-rescue requirements — a minimum clear opening, minimum height and width, and a sill within reach of the floor. If a replacement would shrink an opening below that threshold, the design has to account for it, so we check egress before ordering.

Permits protect resale. Most San Leandro window replacements are permitted quickly, and pulling the permit matters beyond passing inspection: unpermitted work has a way of surfacing later — in disclosures, an appraisal, or a buyer's inspection at resale — and becoming a problem to unwind. Keeping the job on the record avoids that. We handle the permitting as part of the project.

Mostly flat, a note for the slopes. San Leandro is largely bay plain, outside the high-fire terrain that shapes hillside projects elsewhere in the East Bay. The State Fire Marshal's 2025 maps did add some Moderate and High Fire Hazard Severity areas toward the eastern edge and the Bay-O-Vista slopes; if your parcel is up there, exterior glazing can carry added Chapter 7A requirements. We confirm your designation before ordering — for most of the city it isn't a factor.

Doing the exterior envelope too? We also handle siding replacement and James Hardie siding in San Leandro, and we serve the wider East Bay. See finished work in our project gallery.

What affects the cost

Every job prices differently, so we don't post numbers. The drivers: the number and size of openings; frame material and brand; retrofit vs. new-construction; how many openings need tempered safety glazing; whether any egress opening has to be reworked; the condition of the existing framing (rot repair adds scope); and access — upper-story or hillside openings on the eastern slopes take more setup than a single-story ranch on the flat.

Frequently asked questions

Do I need a permit to replace windows in San Leandro? Yes — window replacement is permitted through the City's Building & Safety Division, and most are issued without plan review. Keeping the work permitted also protects you at resale, when unpermitted work tends to surface. We handle the permitting.

Which of my windows will need tempered glass? The ones the code treats as "hazardous locations" — in and next to doors, near walking surfaces, low glazing close to the floor, and around stairs. We walk the house and identify those openings, then spec safety glazing where it's required under San Leandro's guidelines.

Will new windows still meet bedroom egress rules? They have to. Each sleeping room needs an escape-and-rescue opening that meets minimum size and sill-height requirements, so we check egress on those openings before ordering to make sure the replacement keeps you compliant.

Retrofit or new-construction — which is right for my home? Retrofit keeps the existing frame and is less disruptive; new-construction strips the opening to the framing so flashing can be fully renewed, which is the better call where there's rot or water damage. We assess your openings and recommend.

Get started

Get San Leandro windows measured, specced to the city's guidelines, and installed right the first time. Request an estimate or call Bay Area Siding Company at (415) 619-5167.