Repeated patterns create calculated harmony and a sense of infinity, important for a funerary structure. Patterns of great variety, executed in baked brick include basketweave, checkerboard, "dog tooth" ornament (on spandrels and the main dome), borders of rosettes, floral ornaments, ribbons, and bands of pearls. There is a notable consistency between the exterior and interior decor in terms of patterns, materials and approach and this signifies that the construction was most likely performed by the same person or team. Repeat pattern of decor and general symmetry were helpful during the restoration works in 1930s as archaeologists used surviving elements to restore those that had been lost. Careful studies of the type of materials, mortar, patterns, thickness and forms of historic layers were conducted before the restoration works began. Prior to renovations, most of the damage was located at the gallery level. Some time during the 20th century, metal screens were installed within the portals to restrict access to the building. It is not known if the original portals had any screens installed.