Vertical green facades have become increasingly popular in urban environments over recent decades. Leonard Ng attributes their emergence to good intentions, such as counteracting the diminishing presence of nature as cities develop and expand. But do they make development more sustainable?
Leonard Ng was recognised as ‘Designer of the Year’ in Singapore’s President*s Design Award 2023 for his passion and commitment to creating harmony between the city and nature.
© Ivan Loh, Pigscanfly
The application of landscape on, in, and around buildings often prioritises aesthetic appeal over its potential to achieve more fundamental purposes. Its benefits, suggest Leonard, can go far beyond cosmetic enhancement.
Leonard practises in tropical Singapore where the profusion of greenery on buildings is not only supported by the climate, but also by regulations. He delineates two primary methods for integrating greenery with buildings: applying vegetation to walls and roofs; and modulating built forms with spaces in which plants can be experienced as gardens.
Oasia Hotel Downtown in Singapore was designed by WOHA with green walls wrapping the facade, as well as sky gardens in large atria. The greenery amounts to a 1,110% green replacement of the site area. WOHA collaborated with landscape consultant Sitetectonix on the project, which was completed in 2016.
© Darren Soh / WOHA
The question is: What do we need such greenery to achieve? Beyond appearances, Leonard suggests we consider the potential performance of integrated vegetation and its capacity to contribute to sustainability goals.
At Oasia Hotel Downtown, WOHA used greenery as an architectural surface treatment, which reaches from ground level to the apex of the mesh-clad tower. By touching the ground, the green facades (consisting of 21 species of creepers) welcome land-based fauna into the vertical landscape.
© Patrick Bingham-Hall / WOHA
He identifies various key performance indicators (KPIs) that will help with evaluating decisions at the drawing board.
The mitigating effect of greenery upon heat gain in buildings is a clear and easily measurable example of its performative potential. Other KPIs include greenery’s potential to attract biodiversity, enhance the wellness of people, provide a means for managing water, and improve the recreational appeal of spaces.
Jewel Changi Airport (completed in 2019) is a commercial building at Singapore’s Changi Airport known for its internal garden and waterfall. It was designed by Safdie Architects, RSP Architects Planners & Engineers, PWP Landscape Architecture, ICN Design, and other collaborators.
© Supanut Arunoprayote, used under Creative Commons Attribution 4.0 International Public License via Wikimedia Commons
Leonard cites Kampung Admiralty, a prototypical public housing project for seniors in Singapore, as an example of the seamless integration of landscape, water, and architecture within a high-rise structure.
Kampung Admiralty is a public housing complex in Singapore designed by WOHA and Ramboll Studio Dreiseitl (now Henning Larsen) and completed in 2017. Its roofscape of terraces and local plants functions as a community park and farm.
© Patrick Bingham-Hall / WOHA
Leonard led the landscape design for this project. The roofscape has been transformed into a community recreation space and farm with staggered terraces covered in local plants.
A stormwater management system collects, cleans, and reuses water for irrigation, contributing to water conservation efforts. Furthermore, the therapeutic benefits of proximity to nature and an environment for exercise enhance the overall quality of life for occupants.
At Kampung Admiralty, greenery covers 53% of the area of the site (which was previously an unused field), but over 100% green area replacement was achieved.
© Patrick Bingham-Hall / WOHA
Clearly, there are many possible benefits to bringing plants and buildings together. Leonard also acknowledges the challenges, including the cost of installation and the potentially unforeseen costs of ongoing maintenance.
Another flip side is the increased infiltration of so-called pests into our spaces. He suggests a shift in mindset towards cohabitation rather than eradication.
Cultural centre CaixaForum Madrid in Spain (completed in 2008) was designed by Herzog & de Meuron and Mateu i Bausells Arquitectura. It features a vertical garden developed in collaboration with artist-botanist Patrick Blanc and Benavides & Lapèrche.
© Zurateman, used under Creative Commons CC0 License via Wikimedia Commons
Similarly, he advocates consciousness of the naturally evolving character of natural systems. Landscape, as he explains, is a dynamic entity that ebbs and flows as the seasons change. A green wall will never be an unchanging backdrop, and expectations about appearance should be managed accordingly.
RMA Architects designed the KMC Corporate Office in Hyderabad, India (completed in 2012) with a double-skin facade. The outer layer is a trellis for plants that help to cool the building and prevent the build-up of dust on windows. The vertical greenery created a new avenue for the employment of gardeners.
© Carlos Chen
Integrated greenery can achieve impressive outcomes, but it’s crucial to think beyond the cosmetic and set realistic goals about what is feasible in your context. Leonard encourages interdisciplinary collaboration within the project team from inception as a key ingredient of holistic, sustainable outcomes.
By striking a balance between the buildings and natural ecosystems, designers can help to mitigate the impacts of climate change while benefiting both people and planet.