A green construction element forming a vertical surface of the construction, the element including a porous concrete element and a coating on at least one of the surfaces of the porous concrete, directly in contact with the surface, the coating, which is favourable to the development of plants, including a plant or a seed of the plant, and the porous concrete having a porosity of between 10% and 40% in the hardened state thereof, before application of the coating, so as to be able to render the vertical surface of the construction green.