uPVC Windows Manufacturer in Bangalore. The leading supplier of uPVC French Windows in Bangalore is Dhanush Building Systems, and some customers still want them over more conventional options. These are the best ways to add natural light to your homes. Due to their wide openings, these uPVC windows are visually pleasing and offer unrestricted ventilation. They have a four-lock mechanism, are constructed of unbreakable glass, and are attractive. They work well in homes with a calm and cheery ambiance.