Conditions come before the product choice
Sill condition, flashing, frame material, glass package, trim restoration, and how much sun a wall gets all matter as much to the outcome as the window itself.
Build a complete scope
- What is installed now, and whether older sash is worth restoring
- Whether paint layers in the oldest housing govern how work may proceed
- Every opening measured, since the older stock is rarely standard
- Frame material and thermal break sized for a northern Illinois winter
- Sealing at the perimeter, trim made good, old units hauled away, and cover
Elgin context
Elgin's housing stock splits into two eras worth knowing before ordering replacement windows: the 1880s–1920s homes in the Elgin Historic District and the 1886–1920 Spring/Douglas Historic District, added to the National Register in 2002, that were framed around original double-hung wood sash and non-standard opening sizes, and the later infill built after the Elgin National Watch Company's 1864–1969 run ended, which mostly took standard-size openings. Confirming which era a given house falls into is the first step in scoping a window-replacement project here.