Double-hung windows have two sash in a single frame, which slide up or down to provide ventilation. Because their sash remain flush with the wall while the window is open, they are a good choice for placement adjacent to patios, decks and walkways. Andersen® 400 Series Woodwright® double-hung windows feature thick, sloped sills, precision-milled wood interiors and historically accurate grille patterns, which bring authentic old-world character to homes of all ages.