The ‘Yorkshire Light’ is most probably the oldest design of sliding sash window. It is a simple window: one section slides horizontally and there is no mechanism to assist movement.
The horizontal-sliding sash window can be subject to water ingress and draught problems. So, we manufacture replacement windows with a number of modifications in order to make our windows more resistant to water ingress and less draughty. We also recommend using Accoya® when we manufacture new windows because of its proven longevity and stability.