The German University of Technology in Oman, GUtech, on 14 December 2021, celebrated the finishing of the 3D printing of the walls of the so far largest 3D printed building in the world made with a real concrete. The house consists of 190 square meters and is typical for a social housing unit in Oman. It has 3 bedrooms, three bathrooms, a living room, kitchen, and guest reception area. The house was printed in two stages. While the materials recipe was adjusted and training of the Omani crew took place during the printing of the first part of the house, the second part of the house was done by the Omani crew on their own and it only took five days to complete.While the Middle East have seen numerous 3D printed buildings, the 190 square meter building in Oman is the first to be printed with a real concrete instead of the traditional dry mix mortars used in most other 3D printed buildings. To make the concrete 3D printable, GUtech applied the D.fab solution developed by COBOD and CEMEX in cooperation where the concrete can have particle sizes up to 10 mm and is made from locally available cement, sand, and gravel. CEMEX and COBOD launched the news about the D.fab solution last week in connection with the first 3D printed building in Angola. The D.fab solution was also used in Angola with the result that the cost of the concrete materials was less than 1,000 USD for the 52 square meterIn the case of Oman, more than 99.5% of the materials used were local, with less than 0.5% coming from Europe in the form of the D.fab additives. In Oman the cost of materials for 3D printing of the walls of the 190 m2 (2.100 SF) house was less than 1,600 Euro. According to COBOD, if a printable dry mix mortar had been used the cost of the materials would be more than 20,000 Euro, and it was such significant cost reductions which COBOD and CEMEX was aiming for with their cooperation.