How to Paint a PVCU Exterior Door Upvc pvcu sidelight-front door-white-porch-white-external-exterior-double-glazed originally it had a white panel fitted. UPVC / PVCu White Fixed window. Glazing is 28mm thick Double Glazed, Distorted with oak leaf pattern, toughened with Metal silver spacer bar, Low E, filled with Argon Gas for extra efficiency.