Green Fenster Industries We are the best UPVC Windows/sliding windows service providers and manufacturer in Chennai. UPVC windows are the great option for your living and office space. It is a one of the best trending window type. This is not only famous for this model as well as quality and stability of the material. Very easy to maintain.The material is also a good insulator, making your house warm in winters and cool in summers. At Green Fenster, we manufacture AtGreen Fenster, we manufacture Fixed Windows, Casement windows, Sliding Windows, Top Hung windows, and Combination windows.