Accoya® Wood is a modified wood made by the process of acetylation. It has a class 1 durability according to EN 350-1 (= highest durability class, at least as good as the best performing European and tropical hardwoods) and exceptional dimensional stability. These properties make it well suited for external applications such as windows and doors, cladding, decking, outdoor furniture and when stress graded for structural applications such as bridges.

By significantly enhancing the durability and dimensional stability of fast-growing and abundantly available certified wood, Accoya® Wood provides compelling environmental advantages over slow-growing hardwoods (which are often unsustainably sourced), woods treated with toxic chemicals, and non-renewable carbon-intensive materials such as plastics, metals and concrete. The durability translates to an expected service life of 60 years for external cladding and decking more than 20 cm above the ground.