Accoya® is an acetylated timber manufactured from sustainably sourced Radiata pine. Through a proprietary acetylation process, the hydroxyl groups in the wood cell walls are replaced with acetyl groups, significantly reducing the wood’s ability to absorb moisture. This modification improves dimensional stability, durability and resistance to biological decay without introducing toxic preservatives. As a result, Accoya is widely used in high-performance window frames where stability and longevity are critical. The material can be machined, coated and finished using standard woodworking techniques and is compatible with conventional joinery systems. Accoya windows are designed to maintain dimensional stability in demanding exterior environments and are often specified for projects requiring long service life and reduced maintenance.