Free in-home measure and quote - PGT, CGI and CWS impact lines compared on your actual openings, style by style
Fast, Reliable Window Replacement Across San Lorenzo
Window replacement in San Lorenzo usually means pulling out a 65-year-old single-pane aluminum unit that salt air has pitted to the point of seizing, squaring a rough opening that clay soil has racked out of plumb, and setting a frame that will stay true through forty more years of marine layer. Most jobs run between $850 and $2,600 per opening depending on material and whether we do a full-frame or insert replacement. If you need an honest look at what your windows actually need in San Lorenzo, call (888) 635-0804. Our Window Replacement crews know the postwar tract homes here block by block, because we work in them every week.
Why TruePane Windows & Doors Is San Lorenzo’s Preferred Window Replacement Company
TruePane has spent years earning a reputation for square deals and straight answers across the East Bay. When we come to a San Lorenzo home, we’re stepping into a house built between 1945 and 1960, often with the original windows still in place. That means we already know what we’ll find before the first piece of trim comes off: aluminum frames corroded by bay air, sash hardware frozen with salt, and rough openings that have shifted in the area’s expansive clay. Our background-checked, uniformed technicians measure every opening twice, quote manufacturer lines side by side on paper, and register both warranty layers in writing before the truck leaves the driveway. Dale Kessler founded this company on a rule that still governs every install: if the pane is not true, the job is not done.
We stand behind the work in writing. Every San Lorenzo window replacement is covered by the Done Right Promise and The Keystone Standard. If something is not right, we make it right. No paperwork fights, no arguing. San Lorenzo homeowners call rather than click, and they expect a company that answers the phone with a human voice. We do that, 24 hours a day, seven days a week.
Our Window Replacement Services in San Lorenzo
Most San Lorenzo homes share the same three or four window styles repeated block after block. We replace all of them, including sliding and patio doors in San Lorenzo, but these are the services that matter most here.
Full Frame Replacement
Full frame replacement is the dominant job in San Lorenzo, and it is not close. The original aluminum windows on these 1945-1960 tract homes are 65 to 75 years old, and the frames themselves have corroded from decades of salt-laden air off San Francisco Bay. When the frame is pitted, bowed, or leaking at the rough opening, an insert window does nothing useful. Full frame replacement removes everything down to the studs, lets us re-square the opening, properly flash the perimeter, and set a new frame that actually fits. In San Lorenzo’s clay-soil neighborhoods, we regularly find openings racked 3/8 inch or more out of square. Full frame work is the only way to correct that.

Insert Window Replacement
Insert replacement works when the existing frame is still structurally sound and square. That is uncommon in San Lorenzo’s older tracts, but when the sill and jamb are intact and only the sash and glass are gone, an insert saves the homeowner money and preserves the home’s original trim profile. We measure every opening twice and only recommend inserts where the frame can honestly carry another generation. On homes near San Lorenzo Creek where moisture has started on the sill plate, we tell the homeowner the truth: inserts are not the fix.

Storm Window Replacement
Storm windows have a specific role in San Lorenzo’s damp microclimate. Many 1950s tract homes here were built without double-pane glass, and some homeowners use storm windows over single-pane units to cut condensation in winter. That condensation is worse here than most of the East Bay because San Lorenzo Creek adds a secondary moisture source on top of the bay’s marine layer. We replace existing storm windows and can supply new ones sized to the original postwar sash dimensions. But in most cases, we will show you the math on a modern low-E double-pane replacement, because it outperforms a storm window while eliminating the maintenance of a second sash.

Energy-Efficient Upgrade
San Lorenzo’s marine layer means single-pane glass loses heat to the outside for ten months of the year, then traps moisture in the summer when the fog rolls through. Replacing 1950s single-pane windows with energy-efficient windows in San Lorenzo changes both the comfort and the utility bill. We quote Andersen, Pella, Marvin, Milgard, PGT, CGI, and ES Windows side by side on paper so you see exactly what you are buying. The energy conversation in San Lorenzo is different from inland cities like Dublin or Livermore: the goal here is not just insulation, it is controlling condensation and salt corrosion.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in San Lorenzo
TruePane is an authorized installer for more than a dozen manufacturer lines, including, PGT, CGI, and ES Windows. For San Lorenzo’s coastal flats, we often recommend vinyl or fiberglass frames with stainless hardware rather than aluminum, because salt air eats aluminum faster here than anywhere else in the East Bay. We stock common parts and hardware for the window lines most often found in San Lorenzo’s postwar tracts, which means faster turnaround when a hardware replacement is all you need. Every job gets both warranty layers registered in writing before we leave.
Common Window Replacement Problems We See in San Lorenzo Homes
- Salt-pitted aluminum frames and seized sash hardware. Marine air off San Francisco Bay carries salt that settles into aluminum window frames. After 60-plus years, the frames pit and the sash locks and balances seize. This is the single most common reason we get called to a San Lorenzo home.
- Racked rough openings from expansive clay soil. San Lorenzo’s flatlands sit on clay that expands and contracts with seasonal moisture. Post-and-pier and slab foundations move just enough that window openings shift out of square. A stock replacement unit will not seal properly until the opening is re-shimmed and squared.
- Condensation and rot near San Lorenzo Creek. Homes in the blocks near the creek carry extra moisture in the air from the waterway itself. Single-pane glass fogs, thresholds rot, and exterior casings swell. If we see rot at the sill plate, we address it during full frame replacement, not after the new window is in.
- Failed seals on first-generation double-pane retrofits. Some San Lorenzo homeowners had early double-pane units installed in the 1980s and 1990s. Those seals are now failing, showing fog between the panes that cannot be cleaned. Seal failure on 30-year-old glass is a permanent condition. Replacement is the fix.
Pricing for Window Replacement in San Lorenzo, CA
Window replacement pricing in San Lorenzo runs on a repeatable range because the housing stock is so uniform. A standard insert window replacement in a tract home here typically costs $850 to $1,600 per opening for vinyl, and $1,200 to $2,200 for fiberglass or premium vinyl lines. Full frame replacement, which most San Lorenzo jobs require, runs $1,400 to $2,600 per opening depending on the window size, frame material, and glass package. Energy-efficient upgrades with low-E, argon-filled glass add roughly $150 to $300 per unit over base glass. A whole-house replacement on a 1,200-square-foot San Lorenzo ranch with eight to ten windows typically lands between $11,000 and $24,000. These are real numbers from the jobs we do here, not internet averages. The free estimate we give you is the price we stand behind. Call (888) 635-0804 to schedule yours.
Key Takeaways for San Lorenzo Homeowners
- Most San Lorenzo homes still carry original single-pane aluminum windows from 1945-1960.
- Salt air from the bay and moisture from San Lorenzo Creek make aluminum frames and hardware fail faster here than inland.
- Clay-soil settling means most rough openings are out of square and need re-shimming.
- Full frame replacement is the most common job we do in San Lorenzo, not insert work.
- Both warranty layers get registered in writing before our truck leaves your driveway.
We Also Serve Cities Near San Lorenzo
TruePane serves San Lorenzo and the surrounding East Bay communities full-time. If you are in Window Replacement in San Lorenzo or any nearby area, you get the same local crews, the same written warranty registration, and the same Done Right Promise. We work regularly in Castro Valley, San Leandro, Union City, and Oakland, and our scheduling is coordinated from our San Francisco Bay Area office. Call (888) 635-0804 and a person answers.
Serving San Lorenzo, CA - Our Local Coverage Area
We’re based in the San Lorenzo area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - Window Replacement in San Lorenzo
San Lorenzo was built almost entirely between 1945 and 1960 as tract housing for returning veterans, and a large share of those homes never got a window upgrade. The original aluminum windows are now 65 to 75 years old. They should be replaced when the frames show visible pitting or corrosion, when the sashes no longer operate smoothly, when you see condensation between panes, or when drafts are obvious in winter. If your windows are original to a San Lorenzo tract home and you have not replaced them, it is time for an honest assessment. Call (888) 635-0804 and we will walk you through it.
Salt air accelerates corrosion on aluminum window frames, sash hardware, and screen clips. In San Lorenzo’s flatlands near the bay and the creek, aluminum frames pit and seize years before they would in inland cities. For homes near the water, we recommend vinyl or fiberglass frames with stainless hardware. Vinyl does not corrode, and fiberglass is dimensionally stable and holds paint well. Aluminum is not automatically a bad choice, but in San Lorenzo’s marine environment it requires a marine-grade finish and stainless hardware, which narrows the cost gap with vinyl. We will show you the difference side by side on paper.
It means the rough opening has shifted with the clay soil under your foundation, and a stock-size replacement unit cannot be set properly without correcting the opening first. This is routine in San Lorenzo. Our installers shim and re-square the jamb before the new frame is set, then flash the full perimeter with butyl tape. If an installer skips this step, the new window leaks air and water even if the unit itself is straight. Every San Lorenzo full frame replacement includes this re-squaring work in the quote. Call (888) 635-0804 for a free estimate that accounts for it.
San Lorenzo tract homes were built from a small handful of developer templates, so a few standard rough-opening dimensions repeat block after block. The most common windows are roughly 32-by-54 double-hungs, 36-by-36 sliders, and 48-by-48 picture units, but decades of clay-soil settling mean almost every opening has drifted enough that each unit still needs custom shimming and re-squaring. We can often source stock-size replacement units, but the installation is never a simple drop-in on a 1950s San Lorenzo ranch. Call (888) 635-0804 and we will measure your openings and tell you exactly what fits.
Most San Lorenzo homeowners replacing original single-pane aluminum windows with double-pane low-E units see a 15 to 25 percent reduction in heating and cooling energy use, with the biggest difference coming in winter when the marine layer keeps temperatures damp and cool. The comfort change is usually more noticeable than the dollar savings: rooms stop feeling drafty, condensation on glass disappears, and window hardware actually operates. For homes near San Lorenzo Creek that fight constant interior moisture, new sealed double-pane glass makes the biggest difference. Call (888) 635-0804 and we will help you figure out which upgrade makes sense for your home.
Written by Dale Kessler, Owner at TruePane Windows & Doors, serving San Lorenzo and the East Bay since 2008.



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