Vinyl doesn't suit every house. A 1900s Victorian on a Petaluma side street, a craftsman bungalow a few blocks off the Sonoma Plaza, a ranch house with a wall of glass facing the vineyards. The original windows on homes like these were part of the design, with thin frames, deep sills and real wood you could see from the street. Swap them for chunky white plastic and the house loses something you can't get back with paint. That's where wood and fiberglass come in. Wood keeps the character inside and out. Fiberglass gives you a slim, strong frame that barely moves when a 100-degree afternoon hits the glass, and it takes paint like wood does.
Below we cover which homes call for each material, how clad wood and fiberglass are built, what our installs involve and how to pick between the two. If you're still weighing every option, our main window replacement page walks through the full job, from signs it's time to what drives the price.
Homes That Call for Wood or Fiberglass
A few situations point straight past vinyl. Older homes with original trim, divided-light windows or a historic look are the obvious ones. If your house is inside one of Petaluma's historic districts, the city has special rules for exterior changes, windows included, so we check before anything is ordered. Big openings are another: picture windows, wide sliders and tall glass walls need a frame that stays stiff without getting bulky, and fiberglass does that well. Hot inland walls count too. In Healdsburg and up the Alexander Valley, south- and west-facing glass takes a beating every summer, and fiberglass handles that heat with very little expansion. And if you want a dark color outside, both materials hold it better than vinyl.
Clad Wood and Fiberglass, Built Differently
Most wood windows sold today aren't bare wood. They're clad, meaning real wood faces the room, where you can stain or paint it to match your trim, with an outer skin of aluminum or fiberglass that sheds rain and sun. That skin is why a clad window can go decades without the rot and repainting that ruined the originals. Fiberglass windows are made a different way. Glass fibers are bonded with resin and pulled through a mold into hollow frame pieces, a process called pultrusion. The result is strong and stable, and because fiberglass grows and shrinks with temperature almost exactly as much as the glass it holds, the seals stay tight through hot days and cold nights. Both come with dual-pane Low-E glass, and both can be ordered with a tempered pane for fire hazard zones.
Our Process for Wood and Fiberglass Installs
These windows reward careful work. We start by checking the old frame and sill for rot, which is common in the damp parts of the county and on older homes where the paint has failed. Soft wood gets cut out and repaired, or the frame comes out entirely for a full-frame install. Each opening is measured several times, since custom wood and fiberglass units take longer to build and a wrong size is an expensive mistake. On install day, the window is set on shims, leveled, fastened and sealed against water, with flashing tape lapped under the sill and up each side. Inside, we fit trim to match what's there, or leave the wood ready for your painter. Wood interiors usually arrive primed or unfinished, so plan on a stain or paint coat afterward.
Wood or Fiberglass: Which One Applies to Your Home
If the inside of the window matters most to you, go with clad wood. Nothing else looks or feels like real wood trim around a window, and it suits craftsman, Victorian and farmhouse homes best. If the outside and long-term upkeep matter more, fiberglass is hard to beat. It won't rot, it won't warp in the heat and it can be painted any color you like down the road. Fiberglass also tends to cost a bit less than clad wood, though both run above vinyl. Plenty of homeowners mix them: clad wood on the street-facing rooms where the look counts, fiberglass on the back of the house and the big openings. We'll walk the house with you and suggest what goes where.
Replacing the slider at the same time? Our patio and sliding door replacement page covers wood-clad and fiberglass doors that match these windows.
Common Questions
They are if the look of the house matters to you and you plan to stay. Clad wood keeps the warmth of real wood inside while the outer cladding protects it from weather, so you get the character of the originals without the constant scraping and painting. For a rental or a newer tract home, the extra cost is harder to justify, and vinyl or fiberglass usually makes more sense.
Factory finishes on fiberglass hold up well against sun, and they don't need painting to stay protected. If you want a new color years from now, fiberglass can be painted, which sets it apart from vinyl. A light cleaning once or twice a year keeps the frames looking right, especially on the sunny sides of the house.
Usually, yes. Most wood and fiberglass windows can be ordered with grilles that mimic the old divided panes, either between the glass or applied to the outside and inside surfaces for a more authentic shadow line. We'll look at your existing windows, count the panes and match the pattern as closely as the product allows.