bies-from-wildland: gleanling:A truth window (or truth wall) is an opening in a wall surface, create
bies-from-wildland: gleanling:A truth window (or truth wall) is an opening in a wall surface, created to reveal the layers or components within the wall. In a strawbale house, a truth window is often used to show the walls are actually made from straw bales. @slavicafire -- source link