We have been making Aluminium sash windows for over forty years and Upvc sashes for over eight We estimate there are over 500,000 Clearview sash windows in the field operating today We have been manufacturing Spectus Upvc sash windows for over 10 years.. By incorporating a polyurethane or polyamide thermal break in our section designs, Aluminium becomes thermally efficient, reducing heat loss and saving precious energy From there we identified a niche market, and became the specialists in Sash windows we are today