In these work Survey about different types of affordable housing was dond with the advantages and disadvantages of each type. The combtability of each type with sustainable in construction according to national and international standards was considered. The risk assessment related to this type of construction was evaluated. The Egyptian innovation in the affordable housing which is registered as patent in the egyptian patent office is studied. The new building has one floor with spherical external shape for energy conservation , it is consists of multilayers movable walls moving on the streams. The metalic structure is installed in the soil surface by fixation elements, it is equipped with sensors which is controlled automatically to detect climate changes. the movement of successive layers can be controlled manual or automatic according to climate changes, The movement of insulated layers is done by sliding on dedicated channels, It is equipped with upper and lower ducts located on several axes positioned at the top and bottom of the ball so that the upper and lower positions are located on one axis. The unit has conical top contain the layers folded to the top and prevent the accumulation of dust and water. The layers can be stored inside the conical top. The Egyptian patent model is compared with the common global models of affordable housing to explain its advantages and disadvantages