Start with conditions, not a product
Regardless of frame material, flashing and sill prep still determine real-world performance.
Build a complete scope
- Whether original sash is repairable, which is common in the older neighborhoods
- Openings surveyed one at a time instead of ordered from a size chart
- Frame material and thermal break for Ohio Valley winters
- How the opening is flashed against wind-driven rain on exposed elevations
- Casing and sill made good both sides, haul-away, and the cover offered
Lexington context
The useful local fact for windows is timing, not geology. Fayette County's 1958 urban growth boundary concentrated residential construction inside a defined urban service area from the 1960s through the 1990s, which means a very large share of Lexington's housing received its original windows within one comparatively narrow span -- and those units are now aging out together, which is why so much of the metro faces this decision at once. The older in-town neighborhoods are the exception worth checking before quoting anything: original wood sash there is often repairable, and openings are rarely standard sizes. The rest of the local picture reaches windows hardly at all. Karst limestone, the county's springs and sinkholes, and the crawl-space foundations under most of the metro are all ground-and-water facts, and an opening in a wall does not engage them. What decides the result is the frame material and thermal break against Ohio Valley winters, and whether the installation is flashed to handle wind-driven rain on exposed elevations.