This guide provides critical information on how to design, operate and maintain these green wall and façade systems to maximise their water treatment benefits to ultimately increase the sustainability and liveability of cities.

Green infrastructure or technologies, essentially, represent a set of engineered elements providing multiple ecosystem services at building and urban scales. They aim to integrate local water management with urban greening. Examples include biofiltration systems (or raingardens), constructed wetlands, green roofs, vegetated swales and ponds, green walls and living walls (or green façade). In particular, the presence of green walls and facades within city precincts has grown tremendously in the recent decades since inception of the concept in the seventeenth and eighteen centuries. Initially designed as aesthetic features, their (additional) merits in terms of easing the urban island heat effect and improving the adjacent building energy efficiency are turning them into highly valued urban assets.