page_title: Window
section_title: Foldup
hierarchical_section_title: Window / Types / Foldup
caption_attribution_description: English: Unlike traditional double hung windows the foldup creates a clear unobstructed opening from sill to header
context_page_description: A window is an opening in a wall, door, roof or vehicle that allows the passage of light and may also allow the passage of sound and sometimes air. Modern windows are usually glazed or covered in some other transparent or translucent material, a sash set in a frame in the opening; the sash and frame are also referred to as a window. Many glazed windows may be opened, to allow ventilation, or closed, to exclude inclement weather. Windows often have a latch or similar mechanism to lock the window shut or to hold it open by various amounts.
  Types include the eyebrow window, fixed windows, hexagonal windows, single-hung and double-hung sash windows, horizontal sliding sash windows, casement windows, awning windows, hopper windows, tilt and slide windows, tilt and turn windows, transom windows, sidelight windows, jalousie or louvered windows, clerestory windows, lancet windows, skylights, roof windows, roof lanterns, bay windows, oriel windows, thermal, or Diocletian, windows, picture windows, Rose windows, emergency exit windows, stained glass windows, French windows, panel windows, double/triple paned windows, and witch windows.
context_section_description: A foldup has two equal sashes similar to a standard double hung, but folds upward allowing air to pass through nearly the full frame opening. The window is balanced using either springs or counterbalances, similar to a double hung. The sashes can be either offset to simulate a double hung, or in-line. The inline versions can be made to fold inward or outward. The inward swinging foldup windows can have fixed screens, while the outward swinging ones require movable screens. The windows are typically used for screen rooms, kitchen pass-throughs, or for egress.
caption: Foldup window (inward swinging), cross-section side view