Free in-home measure and quote - PGT, CGI and CWS impact lines compared on your actual openings, style by style
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AfterFast, Reliable Window Installation Across Fairfax
Window installation in Fairfax runs anywhere from $850 to $4,200 per opening depending on the window type, size, and whether the project triggers Marin County’s WUI fire-safety review. That range covers everything from a standard double hung replacement in a 1950s ranch to a custom casement with tempered, fire-rated glazing on a Cascade Canyon hillside. We’re Westlight Windows & Doors, an independently owned and operated Kingswell location, and we’ve been installing windows since 2009. If you’re weighing options for a Fairfax home, call (903) 354-7134 and we’ll give you a written price before any work starts.
Why Westlight Windows & Doors Is Fairfax’s Preferred Window Installation Company
Fairfax homeowners call us because we answer the phone. Not a voicemail box, not a chatbot – a real person, 24 hours a day. That matters when you’ve got a failed seal on a west-facing window and the first winter storm is two days out. Our crews know Fairfax streets: the tight hillside lots off Bolinas Road, the flat blocks near downtown, the fog-heavy pockets up toward Deer Park. We schedule a real arrival window and show up in it. After the job, we hand you a written guarantee on the work. If something fails within the guarantee period, we come back and fix it at no charge. That’s the 365-Day Done Right Promise, and it’s on every job we do in Fairfax, no exceptions.
Owen Satterfield, who leads our team, built the company around a simple idea: say the price before the work, show up when you said you would, leave the place cleaner than you found it, and come back if it fails. That’s the Kingswell Way, and it’s why Fairfax homeowners who’ve been burned by no-show contractors or door-step price revisions tend to stay with us for every subsequent project.
Casement Windows in Fairfax
Casement windows in Fairfax are a smart choice for the town’s west- and north-facing elevations, where wet-season wind-driven rain hits hardest. These are windows hinged on one side that crank outward, and when they close, the sash presses tight against the weatherstripping to form a seal that holds up far better than a sliding or double hung unit in wind-driven rain. A typical casement window replacement in Fairfax runs $950 to $2,800 installed, with the higher end reflecting custom sizing and WUI-compliant glazing on fire-hazard lots.
How the Sealing Works
Casement windows use a compression seal – the sash physically squeezes against the frame when you close the crank. That’s different from a sliding window, which relies on brush seals that degrade over time. On a Fairfax home where fog lingers in the valley well into the afternoon, that compression seal matters. It keeps condensation-driven moisture out of the jamb, which is exactly where redwood framing fails first.
For homes in the High Fire Hazard Severity Zone, casement windows often require tempered glass or dual-pane fire-resistant glazing. We price that into the written quote before we order anything, so the permit review doesn’t surprise you later.
Double Hung Windows in Fairfax
Double hung windows in Fairfax are the most common replacement we do, largely because the town’s 1920s-1950s cottages and bungalows were built with them and the original sashes have reached the end of their service life. Both the upper and lower sash slide vertically in a double hung, which gives you venting options and makes them easy to clean from inside – useful on tight hillside lots where exterior access is awkward. Expect to pay $850 to $2,200 per opening for a standard double hung replacement in Fairfax, installed.
Why Custom Sizing Is Usually Necessary
Almost none of the rough openings in Fairfax’s older homes are plumb or level. Century-old redwood framing has settled, warped, and absorbed decades of fog moisture. When we measure for double hung replacements, we’re almost always ordering custom-sized units rather than pulling stock sizes off the shelf. That adds about two to four weeks to the lead time, but it’s the difference between a window that seals tight and one that leaks air from day one.
Dealing With Rotted Sills
The sill is the horizontal board at the bottom of the window opening, and in Fairfax it’s usually redwood that’s been wet for 70 years. We regularly find sills rotted beyond acceptable tolerance. In those cases, we rebuild the sill and jamb before installing the new unit. It’s a separate line item on the quote, and we walk you through exactly what we found and why it needs doing before you approve anything.
Trusted Brands We Service in Fairfax
We carry eight manufacturer lines so the product matches the job, not the other way around. For Fairfax homeowners, the brands that come up most are CGI for their impact-rated and fire-resistant glazing, ECO Window Systems for energy-efficient double and triple pane options, and CWS for custom architectural window configurations. Because we stock parts for these lines and others, we can turn around service calls and warranty work in Fairfax faster than contractors who special-order every component. If you’re replacing windows on a Cascade Canyon slope or a fog-saturated north side, we’ll recommend the specific manufacturer and glazing package that makes sense for that exposure – not just the brand we happen to have in inventory.
Common Window Installation Problems We See in Fairfax Homes
- Rotted jambs and sills from persistent fog. The ridgelines around Fairfax funnel marine fog into the valley floor even on days when San Anselmo is clear. That chronic damp keeps wood window framing wet for weeks at a time, and we routinely find sill rot hidden behind what looks like cosmetic wear.
- Out-of-square rough openings in 1920s-1950s framing. Century-old redwood settles. A “standard” 36-inch rough opening in a Fairfax cottage is rarely 36 inches, and it’s rarely level. Custom milling is the norm, not the exception.
- Wind-driven rain failures on west and north elevations. Wet-season storms come from the northwest and hit those exposures hardest. Failing weather seals on those sides are a consistent driver of our Fairfax service calls, especially on older sliding and double hung units.
- Unexpected WUI fire-safety requirements. Homes bordering Cascade Canyon open space and other High Fire Hazard Severity Zone pockets trigger a glazing review at permit that can require tempered or fire-rated glass. When that’s not priced into the original quote, it doubles material costs. We include the review in the written price before ordering.
Pricing for Window Installation in Fairfax, CA
Here’s what you can expect to pay in Fairfax, based on the work we’ve done across town:
- Double hung window replacement: $850 – $2,200 per opening
- Casement window replacement: $950 – $2,800 per opening
- Picture or fixed window replacement: $700 – $1,800 per opening
- Bay or bow window installation: $3,200 – $6,500 per unit
- WUI-compliant glazing upgrade (tempered or fire-rated): adds 60-110% to material cost on affected openings
What moves the number is custom sizing, fire-rated glazing requirements on hillside lots, and any sill or jamb rebuild work. The price we give you is the price you pay – it’s written down before we order any materials, and we don’t revise quotes at the door. Call (903) 354-7134 for a free estimate. We’ll walk the property, measure the openings, and give you a line-item price you can sit with.
We Also Serve Cities Near Fairfax
Our crews work throughout the Ross Valley and central Marin. If you’re in San Anselmo, Kentfield, San Rafael, or Larkspur, we bring the same written-price guarantee and the same Window Installation standards to your job. Many of our Fairfax clients come from referrals in these neighboring towns, and the local permitting landscape in each is different enough that it pays to work with a crew who knows the codes. See what we do across the region by visiting our Window Installation in Fairfax page for full local details.
Serving Fairfax, CA - Our Local Coverage Area
We’re based in the Fairfax 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 Installation in Fairfax
Fairfax sits inside a High Fire Hazard Severity Zone, and homes bordering Cascade Canyon open space or other wildland-adjacent streets are in the highest fire-hazard tier. When you pull a permit for window replacement on those lots, Marin County’s WUI review may require tempered or fire-resistant glazing. That can double the material cost on affected openings. We identify whether your home is in the review zone before we quote, so the number on paper already reflects it.
Fairfax’s 35 to 45 inches of annual rain means exterior work has to be scheduled around storm cycles. We don’t pull a window during a heavy rain on a west-facing wall and leave the opening exposed. If a storm is moving in, we’ll stage the job so the rough opening is covered or sealed within the same day. It can push a schedule by a day or two, but it prevents water intrusion damage that would show up six months later as rot. Call (903) 354-7134 and we’ll give you a realistic timing window for your specific elevation and exposure.
Most Fairfax homes need custom-sized windows because the rough openings are not square and not standard. Custom millwork adds two to six weeks depending on the manufacturer, the glazing package, and whether fire-rated glass is required. That’s the honest bottleneck on any Fairfax window project – not labor, not our schedule, but the time it takes to cut and ship custom units. We lock the price in writing before ordering, so the lead time doesn’t become a surprise cost.
West- and north-facing elevations take the worst of it. Wet-season storms in the Ross Valley drive rain from the northwest, and those walls catch the brunt. Add in the fog that settles into the valley floor, and it’s the west- and north-side windows and doors we’re replacing most often. If you’re on a hillside lot where fog lingers later in the day, expect more frequent seal failures and faster sill degradation than a home on the flat blocks near downtown.
Yes, if you’re changing the rough opening size or installing windows on a home in the High Fire Hazard Severity Zone. The review checks proposed glazing against California’s WUI fire-safety standards. On simple same-size replacements outside the fire zone, permit requirements are lighter. We pull the permits, we handle the review, and we call you when the inspection passes. That’s part of the written price.
If you’re ready for a real number on window installation in Fairfax, call (903) 354-7134. Owen and the crew will come out, measure the openings, check whether your home falls in the WUI review zone, and hand you a written line-item price. No door-step revisions, no vague ranges. Just the price, the window, and the guarantee.
Written by Owen Satterfield, Owner at Westlight Windows & Doors, serving Fairfax since 2009.