What makes this green?

This home for seniors was designed with passive solar strategies to keep the interior spaces cool without the use of air-conditioners. Exterior walls made of hollow terracotta Porotherm blocks and well shaded windows keep the interior spaces bright and airy but cool. Vents made by placing Porotherm blocks in a perpendicular fashion provide a vent of hot air to go out. A courtyard in the centre of the building helps bring in natural light to the inner spaces and vent hot air. The façade made of exposed Porotherm blocks also helped reduce the use of cement.