Sliding Sash Windows ~ these are an alternative format to the
conventional side hung casement windows and can be constructed
as a vertical or double hung sash window or as a horizontal sliding
window in timber, metal, plastic or in any combination of these
materials. The performance and design functions of providing
daylight, ventilation, vision out, etc., are the same as those given
for traditional windows in Windows † Performance Requirements on
page 366.Sliding Sash Windows