Janssens Cathedral Victorian GreenhouseCathedral Victorian Greenhouse with Large Cupola: The majestic Cathedral is one of our largest greenhouses, and distinguished by a cupola. It features significantly more floorspace than even the VI 46. Like all Janssens models its 4mm tempered glass and aluminum frame make it resilient enough to withstand wind gusts and most hail. The Cathedrals structure is additionally reinforced by thick aluminum portal frames which span its entire width,