At Dempsey Dyer, we use the best wood available for sash windows to maintain their authentic appearance combined with exceptional performance. In addition to Sapele, European Oak and Redwood, all of which are high performance wood options for your design, we offer modified and sustainably sourced Accoya. This timber species for sash windows is the high quality available when it comes to durability, for wooden sash windows from the expert manufacturers that will stand the test of time.