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 Kensington
Window replacement in Kensington typically runs $900 – $2,400 per opening for a full-frame unit, and $600 – $1,500 per opening for an insert replacement, depending on whether the home needs WUI fire-rated glazing, custom sizing, or both. Most Kensington jobs take 2 – 4 weeks from signed agreement to install, with custom millwork and fire-rated sash pushing lead times further out. If your original wood windows are fogging, sticking, or letting the marine layer seep in, call (562) 478-8017 for a written quote, no guessing.
We work in Kensington every week, and we know this neighborhood’s houses the way a local should: the 1920s Tudors off Arlington Avenue, the craftsman bungalows climbing the terraces above Colusa Avenue, the Mediterranean stucco homes that catch afternoon sun and evening fog in equal measure. None of them were built for modern window code, and most of them still carry original single-pane wood sash. That is exactly the work we are built for.
Kensington’s status as an unincorporated pocket of Contra Costa County means every permit routes through the county building department, not Berkeley’s or El Cerrito’s. That single fact shapes the entire calendar on a window job here. A contractor who doesn’t know it will promise you a timeline that falls apart the day plan-check opens the file. We know it before we knock.
Why Lightwell Windows & Doors Is Kensington’s Preferred Window Replacement Company
We’re part of the Cedarwell network, operating to the Cedarwell Care Promise since 2010, and led in this area by Keith Yamada. Keith knows the East Bay hills the way only someone who has measured hundreds of pre-war openings can: he’s the one who walks your home, checks the rough opening against the existing sash, and tells you plainly whether you need a custom unit or a stock size will do. No showroom pitch. Just a measured conversation.
Every Kensington job comes with a written price before any work starts, and that price does not move unless the scope changes and you agree to it in writing first. That is not a promotion. It is a standing operating rule. We put it in front of you before we order a single sash, because the cabinetry-grade windows Kensington homes often need are ordered weeks out, and you deserve to know the exact number before that clock starts.
When the crew arrives, they arrive in uniform and background-checked. They wear shoe covers and lay drop cloths before the first ladder opens. They ask before moving furniture or touching anything in a room. If your child is napping, we adjust the schedule to work quiet. If your dog is anxious, we use pet-safe sealants and keep cords and tools out of reach. Every day ends with a photo of the cleanup before the crew pulls out of the driveway. That is the C.A.R.E. values at work: Clean up like it’s our own home, Ask before we move or touch anything, Respect your time and quiet hours, Explain the price before the work.
And if something is not right after the job is done, the 365-Day Done Right Promise is simple: we make it right. No debate, no countdown. You call (562) 478-8017, a live person answers, and we come back.
Window Repair in Kensington
Window repair in Kensington usually means one of two things: a sash that has swollen into its frame from the near-daily fog cycle, or a seal that has failed and left condensation between the panes of an otherwise modern unit. Most repair work in this neighborhood runs $180 – $600 per window, with custom-milled wood sash on 1920s – 1950s homes on the higher end.
Sticking and Swelling Original Wood Sash
Kensington’s microclimate is unforgiving to original wood windows. Afternoon sun bakes the west-facing sash; evening fog rolls in off the Bay and swells the wood; the cycle repeats the next day. After seventy or eighty years, the sash no longer opens without force, and forcing it cracks the hardware or breaks the counterweight cord. We true the jamb, recut the sash where there is enough material, and replace corroded hardware with stainless fasteners. When repair is possible, it keeps original character intact and saves thousands over full replacement.
Failed Seals on Existing Insulated Units
Salt-laden fog accelerates seal failure in this neighborhood faster than in flatland cities below the hills. You will see it as a permanent haze between the panes that cleaning cannot touch. We replace the glass pack without disturbing the existing frame when the frame is sound, and we do it with low-E insulated units matched to the home’s orientation. The fix typically runs $220 – $480 per sash.
Window Replacement Company in Kensington
Window replacement company work in Kensington is different from most of the Bay Area because this neighborhood sits inside California’s designated Very High Fire Hazard Severity Zone. Nearly every project here requires windows and doors that meet WUI fire-resistance standards: dual-pane, tempered, and often with laminated glass interlayers. A full-frame replacement in Kensington runs $900 – $2,400 per opening; an insert replacement where the existing frame is sound runs $600 – $1,500 per opening.
Full Frame Replacement for Hillside Homes
Steep terraced lots in Kensington mean many homes have cantilevered construction and rough openings that are no longer square. Stock double-hung units shimmed to fit will rack the sash and quietly defeat the unit’s weather seal within a season or two. We measure each opening to the frame, not to the sash, and order custom-sized units that fit the house as it actually sits, not as the original 1928 drawings intended.
Insert Replacement for Sound Frames
If the existing jamb is solid and square, an insert replacement preserves the interior and exterior trim while swapping the sash and balances for a new, tight-sealing unit. It is the least disruptive route on a Kensington craftsman where the millwork is original and the homeowner wants to keep it. The lower labor cost means insert work lands at the bottom of the pricing range, but it only works when the frame tells us it will.
Trusted Brands We Service in Kensington
Lightwell carries a curated lineup of eight manufacturer brands, and for Kensington homes we most often specify CGI, ES Windows, and ECO Window Systems. CGI’s laminated-glass casements and picture units meet WUI glazing requirements and hold up to the marine air off the Bay. ES Windows gives us the custom sizing and finish work that high-end hillside builds and remodels expect. ECO Window Systems handles the mid-range replacement market well, with tight low-E performance at a fair price. Because we stock local hardware and fasteners for these lines in the Bay Area, turnaround on a warranty part or a replacement sash in Kensington is measured in days, not weeks.
Common Window Replacement Problems We See in Kensington Homes
- Corroded hardware and broken seals from marine fog. Kensington’s position in the East Bay hills pulls dense fog and salt-laden air through the neighborhood on a near-daily basis. Original bronze hardware corrodes, and even modern seals fail years earlier than they would three miles downhill in El Cerrito. We spec stainless fasteners and marine-rated hardware where the exposure is worst.
- Out-of-square rough openings on terraced lots. Homes built into the hillside shift over decades. Cantilevered foundations settle, jamb lines go out of level, and a stock unit simply will not seat. We true the framing before setting the new unit, and we build the true-up time into the written quote.
- WUI code retrofits into 1920s framing. Original framing was never designed for fire-rated glazing assemblies or the heavier sash that comes with them. County plan-check can bounce a permit multiple times if the detail work is not drawn correctly. We handle the county submittal ourselves and coordinate with the inspector directly.
- Failed drainage detailing on earlier replacement jobs. Some homes have already had a window replaced once by a crew that treated Kensington like a flatland job. Missing flashing and shallow sill pans let fog moisture in at the jamb, and rot follows. When we pull an old replacement out and find the rot, we rebuild the sill and add proper pan flashing before setting anything new.
Pricing for Window Replacement in Kensington, CA
A straight insert replacement in a sound frame runs $600 – $1,500 per opening here. Full-frame work, which means removing the old jamb, rebuilding as needed, and setting a new unit, runs $900 – $2,400 per opening. Custom-sized units for the neighborhood’s hillside homes add $150 – $500 per opening over stock sizing. WUI-compliant fire-rated glazing, required on most Kensington properties, adds $180 – $400 per opening, depending on whether the sash needs a laminated interlayer or just tempered glass.
What you will not see is a number that changes at the end. The price goes in writing before anything is ordered, and it covers the permit drawing, the county plan-check, the unit, the install, the flashing, and the cleanup. Call (562) 478-8017 for an exact quote on your home, and we’ll walk the openings with you and show you the math.
We Also Serve Cities Near Kensington
Our Window Replacement team works throughout the East Bay and beyond. In addition to Window Replacement in Kensington, we serve Los Angeles, San Diego, San Jose, and San Francisco. If you’re in a neighboring city and dealing with fog-damaged sash or WUI code confusion, the same written quote standard applies.
Serving Kensington, CA - Our Local Coverage Area
We’re based in the Kensington 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 About Window Replacement in Kensington
Kensington is unincorporated Contra Costa County, so every window permit routes through the county building department in Martinez rather than the city desks in Berkeley or El Cerrito. That means a separate plan-check queue, county-specific detail requirements for WUI glazing, and county inspectors who schedule on their own calendar. We handle the submittal and the back-and-forth ourselves, and we build county plan-check time into the written timeline before you sign. Call (562) 478-8017 if you want us to walk your specific project through the county process.
Yes, in most cases. Kensington falls inside California’s Very High Fire Hazard Severity Zone, which mandates dual-pane, tempered glass, and often laminated interlayers or other fire-rated glazing details on replacement windows and doors. The exact spec depends on your lot’s exposure and the opening’s location, but planning a Kensington window job without WUI compliance will not pass county plan-check. We spec compliant units from CGI and ES Windows as standard practice here.
Custom-sized WUI-compliant sash is not sitting on a shelf anywhere. On a recent terraced lot off Arlington Avenue, a 1928 Tudor Revival needed out-of-level rough openings that no stock unit would ever fit, so we ordered custom CGI casements with laminated glass and low-E coatings and a solid-core Therma-Tru entry to satisfy the fire zone. The framing work took two days, but the calendar was set by the weeks-long lead time on the custom sash. Every line was fixed in writing before the order went in. That is how we protect you from a moving date.
Often, yes. If the sash has enough wood left to recut and the jamb is not rotted, we true the frame, plane the sash to proper clearance, and replace the corroded hardware with stainless fasteners. The repair typically runs $180 – $600 per window and can keep original 1920s millwork in place for another decade. We’ll tell you honestly if the rot has gone too far for repair, because no one benefits from a patch that fails next fog season.
Yes, but in Kensington the bigger shift is comfort, not just the utility bill. Original single-pane wood windows lose heat every evening when the fog rolls in, and low-E insulated units change the interior feel immediately, especially on west-facing walls. Most Kensington homeowners see a 15 – 25% drop in heating-related energy use after replacing original single-pane sash, but the daily difference you will notice first is less draft and less moisture on the sill. For an exact quote on your home, call (562) 478-8017.
Written by Keith Yamada, Owner at Lightwell Windows & Doors, serving Kensington since 2010 as part of the Cedarwell network.










Before
After
Before
After
Before
After