The materials used in 3D printed construction usually consist of different concrete mixtures. The concrete is usually adapted to the 3D printing technology by using less water, some sand and other additives. These materials are said to be very strong, especially after you leave them some time to dry. After two days, some companies claim, the 3D printed house has alreasy reached the stability of their traditionally built counterpart, after that it gets even harder. There has even been a 3D construction project which utilized steel, something that embodies stability. Some projects, like the one from Gaia, have been realized using dirt and soil. While this might raise some concern regarding stability, companies themselves claim these houses to be of extreme stability.