The potential of concrete: textures (140)
A really interesting concrete solution.
As HEARING indicates at their own website "they used triangular fillets as profiled shuttering and were thus ables to cause the grain to protrude evenly from the surface after surface treatment, washing in this case, thus providing the desired structure."
Applying the colour only to a superficial layer of concrete stone aggregate permitted highlighting the openings with this nearly white embrasures.
And pay attention to the extremely precise moulding process that permitted perfectly fitting the precast concrete panel openings in the exact position where the windows were placed in the back concrete wall!!