A pet window hosts a pet door wherein the pet window replaces an existing window screen. For example, the pet window fits securely into a window screen track adjacent and parallel to a window of a movable window sash, in a similar manner as the screen being replaced. The pet window may provide many options: insulation characteristics to minimize outside weather affecting home inside conditions, accessory window(s), solar panel integration, LED light(s), attached gauge(s), attached electric appliance(s), adaptable electric connectivity, an exterior awning, and any of a large range of decorative themes, colors, appearances, and other options.