A window installation and a wall panel and methods for construction thereof. The window installation includes a window liner in which a window unit can be installed. The window liner includes jambs, a header, and a sill that circumscribe the window unit and an exterior flange that depends outwardly from external edges thereof. The wall panel is a prefabricated panel that includes framing with sheathing and insulating members disposed on an exterior surface thereof and forms an opening in which the window liner is received. An external sheathing of the wall panel is formed with a larger opening dimensioned to receive the exterior flange of the window liner. The window liner and window unit can be removed from the wall panel to ease movement and transport of the wall panel and to reduce risks of breaking the window unit during manufacture and transport.