Large-scale construction is in full swing at the V&A Waterfront as the R1-billion transformation of the Clock Tower Precinct into a premier 'lifestyle destination' is taking shape.

Given the historical and natural significance of its positioning, the redevelopment of the Clock Tower Precinct – and in particular the construction of No 1 Silo – is guided by the latest global requirements for environmentally sustainable construction, as governed by the Green Building Council of South Africa.

“Sustainable development is regarded as a fundamental aspect of the V&A Waterfront’s overall development strategy,” says David Green, CEO of the V&A Waterfront. “We have therefore adopted a rigorous approach to green construction and sustainable design principles, and the efficient use of natural and energy resources,” he says.

“Adding to the Clock Tower Precinct’s green credentials, and in an effort to enhance the appearance of the building site, the V&A Waterfront has now taken its commitment to green construction to a whole new level – quite literally!” Green says.

the transformation

The recent installation of vertical gardens on the outer surfaces of the temporary construction site hoardings has seen the transformation of an otherwise drab and dusty building site into a cheerful, interactive focal point.

Covering over 200 linear meters, and equalling a total of 500m², this is the first time in South Africa that construction site hoardings play host to vertical gardens on this scale. Third-party advertising has also been incorporated into the design and installation, resulting in a living, three-dimensional and impactful visual display.

“The concept of vertical gardens, or living walls, is capturing the imagination of urban space designers worldwide. However, it is still a relatively novel concept here in South Africa,” says Alana Robertson of ACR group, responsible for the development, installation and maintenance of this green initiative.

The ‘green hoarding’ initiative is collaboration between the V&A Waterfront’s development team, horticultural experts Greennaissance and the ACR Group, the green consultants on the project.

water-conducting

“The living wall basically constitutes a simple layer of irrigation cloth affixed to the hoarding boards,” she says. “Pockets, cut into the cloth and containing only the minimum required amount of soil, provide a solid footing for plants to establish and grow from,” Robertson explains. The water-conducting irrigation cloth, manufactured from non-degradable deconstructed acrylic textiles, allows for plant roots to firmly spread through the fibres and to absorb water and nutrients.

Robertson explains that the composition and functioning of the irrigation cloth can be compared to a layer of algae or moss covering forest rocks or tree trunks. “All the exchange between plant, water and atmosphere takes place through the irrigation cloth, rendering a soil-free solution and adding to the relative simple concept of vertical gardens,” she says.

The cloth is irrigated via a simple plastic tube incorporated into the top section of the material, and a diluted nutritive solution is added to the irrigation flow. Watering occurs three to five times daily for between one to three minutes, depending on the weather conditions and the stages of plant growth. Plants were carefully selected based on their ability to withstand severe climate and environmental conditions. “Proximity to the ocean, aptitude to sun and shade exposure, as well as the effects of construction had to be considered,” says David Gent of Greennaissance. The different species also had to bear the same growth characteristics and maintenance requirements. “Water-wise, indigenous plants and succulents have been selected as far as possible due to their sturdy growth and natural resilience levels,” Gent says.

long-term sustainability

The long-term sustainability of these plants was also a key consideration. The vertical gardens will remain in this position for the next two years up until the conclusion of this development phase. Once this construction phase has concluded, the panels will be removed and the gardens will be repositioned elsewhere.

“We have not yet identified the exact end-destination, but we are considering a number of worthy locations such as public spaces and community centres in and around previously disadvantaged communities in Cape Town,” Green explains.

These vertical gardens not only enhance the aesthetic qualities of the construction site, but also actively contribute to the improvement of the immediate environment. The leaf surfaces and irrigation cloth trap dust and pollutants emitted by nearby industries, vehicles and the construction process.

Once trapped, the dust is decomposed by water and micro-organisms into chemical elements that are absorbed by the plants. In addition, micro rubber fragments from tire wear on the roads along the hoardings are carried away in puddle spray and deposited on the lower sections of irrigation cloth.

the visual and aesthetic effects

“We have been able to keep water usage to a minimum,” Robertson says. Depending on the plant types, weather conditions and time of year, a typical vertical garden requires between 0.5 to 3 litres of water per m² per day, which is low compared to watering requirements for parks and other gardens.

“It has been almost two months since the first panels were installed, and so far we have experienced great success with plant growth. There has been very little water, soil and nutrient wastage, and wind and heat damage to cuttings and seedlings have been minimal,” she says.
“We have however experienced some plant loss at the hand of over-zealous plant lovers and admirers of the project, but we believe this problem should contain itself as the young plants start to settle firmly into the cloth,” Robertson quips.

“The V&A Waterfront is proud to be leading with this initiative,” Green says. Although it is still early in the project, he says the desired visual and aesthetic effects are definitely being achieved. “We continuously receive overwhelming public support for our green wall, and we are pleased to know that we are able to enhance our visitors’ overall experience through this project,” he concludes.