The retail units all have a concealed drainage system which runs where the wall meets the roof as shown in the structural detail above. The concealed drainage system means that water is carried away effectively from the units and no excess run off runs into the paths of those using the space below. This drain is concealed behind the front facade where it then runs into the greywater system tank which is buried below ground. The water for units is sourced from these tanks creating a sustainable approach to water useage on site.