In the Search for Sustainable Vertical Green Systems: An Innovative Low-Cost Indirect Green Façade Structure Using Portuguese Native Ivies and Cork

Abstract

Green façades in the urban environment represent points of biodiversity value, contributing to species conservation, acting as urban wildlife corridors connecting elements, and also aiming at sustainability, when the materials and structure are thoughtfully chosen. Ivies (Hedera spp.) are perennial climbing evergreen plants that are easy to cultivate and demand little input, and their use in vertical green systems is much appreciated but may lead to damage to the constructions in the long term. Among the 14 species of Hedera currently recognized, a few have been bred into cultivars and are available in the market for cultivation, often as exotic species. Four Hedera spp. are native to Portugal, but most cultivated species in this territory are exotic and the suitability of native species for their use in green façades has not been documented. Thus, in the present work, we describe the installation of a low-cost indirect green façade structure supported on cork panels using plants belonging to the native H. iberica and H. hibernica. The structure is installed at the Ajuda Botanical Garden, under Mediterranean conditions, on a brick and cement wall, and will enable researchers and landscape architects to follow the development of this structure as a long-term experiment, prompting the use of native species toward increased biological and technical sustainability. The preliminary results indicate that the cork structure is able to provide adequate support for the plants and that these were able to climb and develop in this structure, avoiding direct contact with the wall and the possible subsequent damage. Therefore, the structure provides a viable solution to implementing sustainable green façades with native species, on brick-cement walls, able to be replicated in other urban locations under similar environmental conditions.

The Assessment of Residents’ Perception of Possible Benefits and Challenges of Home Vertical Gardens in Kigali, Rwanda

“…However, there are concerns about possible challenges, cost-benefit considerations, and motivations to implement home gardening such as vertical gardens [64]. Despite the increasing value of properties with green spaces [65,66], some issues are considered to discourage dwellers to develop home vertical gardens, such as knowledge, costs, and maintenance [25].…”

“…Second, two questions were asked to know the respondents' general knowledge about vertical gardens and whether they had applied some forms of home vertical gardens [79]. Third, it was the main body of the questionnaire, arranged in five clusters to discover how participants perceive the purposes of creating vertical gardens [14,39,58,59], the possible challenges/risks for householders [25,67,68], the main effects of vertical gardens on urban environments [21,25,30,[54][55][56], the common interests of residents to learn more about vertical gardens [4,14,[57][58][59], and the preferences or concerns about the technology [2,4,46,47] and costs [64,69] of vertical gardens [25,67,68]. Fourth, as the last part, an open question was put to receive any suggestions and recommendations.…”

“…Method: to select critical points for questionnaire in each district of the city residents to learn more about vertical gardens [4,14,[57][58][59], and the preferences or concerns about the technology [2,4,46,47] and costs [64,69] of vertical gardens [25,67,68]. Fourth, as the last part, an open question was put to receive any suggestions and recommendations.…”

Investigating the Effect of Living Walls on Cooling Energy Consumption in Various Urban Microclimates, Building Heights, and Greenery Coverage Areas

“…The use of plants to cover building walls positively affects thermal stability, contributing to energy savings and aiding in the face of climate change. Additionally, such soil and plant ecosystems promote biodiversity and ecological balance in urban environments [43]. Additionally, these green additions not only beautify the surroundings but also help to alleviate pressure on several important aspects.…”

“…However, these living structures also raise concerns, including potential long-term damage to buildings, increased humidity, the release of allergens, and the presence of undesired insects or reptiles if not properly maintained [43]. While living walls offer versatile and multi-scalar benefits in the built environment, they must meet the requirements of social, economic, and environmental sustainability [48].…”