Architect & founder of the NIR Lode Van Pee has provided the details of the foundation works. After a 5 minute explanation, you can scroll down to a vast selection of photos.
There are 36 foundation wells (3 rows of 12). Their depth is determined by the subsoil, as we require a hard rocky base. The row closest to the wall is 120 cm deep, the middle one is 150 cm but the row closest to the slope goes up to 450 cm deep.
To save costs, the latter are first filled with hard rocks, gaining heights up to 150 cm. Supplemented with smaller boulders, this forms the basis for pouring 5 cm of ‘lean concrete’.
On top of this comes the reinforcement and the formwork. Next, the concrete is poured manually and then drilled by machine. The foundation feet are 35 cm high. The foundation wells (4 in total) in each corner of the building will be fitted with a lightning conductor.