I restored 189 windows in my 200-year-old house in Poland rather than replacing them. The windows are fundamental to a building's character and historical authenticity. You can date a building by analyzing its window features. The older the house, the fewer and smaller the windows, often due to glass manufacturing limitations and structural needs. For instance, a 16th-century manor might have small, thick-glassed windows with irregular panes, while an 18th-century townhouse would show taller, multi-paned sash windows.