Start with conditions, not a product
Sill condition and flashing deserve extra care with wood or clad units, given their upkeep needs.
Build a complete scope
- Whether original sash is repairable, common in the older housing near downtown
- Each opening measured on site rather than taken from a schedule
- Frame material and thermal break for lake-effect winters, not glass coating alone
- How the opening is flashed and air-sealed, which outlasts the unit specification
- Trim made good on both faces, old units removed, and the terms of cover
Waukegan context
Waukegan's oldest housing stock, concentrated in the Near North Historic District that reaches back to the 1840s, was largely built before modern window units existed, and later postwar and contemporary construction added its own range of opening sizes and frame materials. Add lakefront wind exposure off Lake Michigan and the freeze-thaw cycle that comes with it, and opening condition, flashing, and frame material matter as much in Waukegan as the glass package itself.