Common in the Loess Plateu, the original house was formerly a ‘yaodong’ or ‘house cave’ — a traditional house carved out of the earth to form a sunken courtyard. The ‘Cave house’ had been abandoned, left in a state of collapse until the time of renovation. The updated home is now separated by function — hyperSity were able to preserve the largest cave, which now acts as the primary living area. The southwest caves were renovated as independent living spaces; a kitchen, bedrooms, bathroom, dining area and storage space. To ensure that sunlight permeates the depths of the cave, skylights have been incorporated, and open-air courtyards connect the living spaces. A central skylight provides a light tunnel made of glass, separating the bedroom and living space of the main home. The rammed earth used to construct the walls is composed of mixed sands and clays from the tops of the surrounding mountains. To ensure a cohesive relationship between the interior and exterior, the use of natural materials continues inside, with wooden walls, furnishings and a timber and glass screen, which allows more light to enter the main building. The entrance to the home is a semi-curved canopy, shielding it from the strong Mongolian wind.