Living walls and green facades : a case study of the UP Plant Sciences vegetated wall

Abstract

The purpose of this paper is to investigate the differences between, and the importance and benefits of, green façades and living walls – both commonly referred to as ‘green’ walls in urban areas. The paper briefly describes the history of the greening of walls over the past 100 years, and the nature of a vertical habitat for plants is discussed. Some examples of green façades and living walls are presented but, as a case study, specific focus is placed on the living wall at the University of Pretoria’s (UP’s) Department of Plant Sciences, where an experimental habitat primarily for succulent indigenous cremnophytes has been established. The design, construction, plant-species selection and performance over the past two years of this project are investigated and presented in detail. The research finds that the differences between green façades and living walls are not merely semantic, but that there are essential differences in terms of wall construction, planting methods and appropriate plant species. The value of the research lies in the fact that the often arbitrary and confusing use of the term ‘green’ wall, which may refer to green façades or living walls, is clarified, and an understanding is shown of the challenges of recreating a cremnophyte habitat; one of the rarest and least-researched plant habitats.