Replacement Window GuideVinyl, wood, and fiberglass are the frame materials most homeowners weigh, and the NFRC consumer guide notes that frame material has a major impact on a window's thermal characteristics. This Old House reports 2026 average installed costs of about 472 dollars for vinyl, 544 dollars for wood, and 564 dollars for fiberglass per window. The sections below attribute each durability and cost claim to the source where it appears.
Why frame material matters
The NFRC consumer guide states that frame material has a major impact on the thermal characteristics of the window. Because the sash and frame represent 10 to 30 percent of the total window area, the guide notes that frame properties significantly influence overall window performance.
That means the choice between vinyl, wood, and fiberglass is not only about looks and budget. It also shapes how well the whole unit insulates and how it holds up over decades of temperature swings.
Vinyl windows
Vinyl is the affordable, popular choice. This Old House lists vinyl at about 472 dollars per installed window, placing it near the budget end of the material range.
Vinyl does move with temperature. Modernize reports that vinyl expands and contracts roughly seven times more than glass, which over years of temperature cycling can stress the unit. For many homeowners the low cost and low maintenance still make vinyl the default pick.
Wood windows
Wood offers a traditional look at a higher price. This Old House lists wood at about 544 dollars per installed window, above vinyl and composite.
Wood moves less than vinyl but more than glass. Modernize reports that wood contracts roughly three times more than glass, and wood generally requires more upkeep than vinyl or fiberglass to protect it from weather. The premium buys appearance and a natural material rather than the lowest lifetime maintenance.
Fiberglass windows
Fiberglass sits at the premium end for durability. This Old House lists fiberglass at about 564 dollars per installed window, the highest of the common materials, and Modernize separately quotes fiberglass installation at about 400 to 1,000 dollars per window.
Modernize reports that fiberglass can last up to 80 years and will not crack, peel, bend, or warp, and that fiberglass frames expand and contract at rates similar to glass, which reduces stress on the unit. Modernize notes fiberglass costs more than vinyl despite a similar appearance, so the case for it rests on longevity and stability.
Where aluminum fits
Aluminum is a fourth option worth knowing. The NFRC consumer guide describes aluminum window frames as light, strong, durable, and easily extruded into the complex shapes window parts require, though aluminum conducts heat readily, which works against thermal performance unless the frame is thermally broken.
On cost, This Old House lists aluminum at about 453 dollars per installed window, the lowest of the common materials it tracks. Aluminum tends to suit specific structural or design needs more than pure energy performance.
Cost comparison at a glance
Putting the materials side by side, This Old House lists aluminum at about 453 dollars, vinyl at about 472 dollars, composite at about 513 dollars, wood at about 544 dollars, and fiberglass at about 564 dollars per installed window.
The spread between the cheapest and most expensive common material is roughly 111 dollars per window on average, which adds up across a whole-house project of seven or more openings. Weigh that gap against durability and maintenance rather than upfront price alone.