As the Sydney visitor grinds by bus along Broadway (we're often not very imaginative in our naming of streets or buildings here in Australia), he or she passes a sight that gladdens the heart of those who are interested in, indeed passionate about, sustainable architecture. I'm a visitor to Sydney myself these days, and I never fail to be uplifted by the vision of One Central Park.
This glossy shopping mall/apartment building, erected on the site of an old brewery, was opened in December 2013 and has received many accolades including a five-star green rating and winner of the World's Best Tall Building award in 2014. It has many features of sustainability, but I'm most interested in the hanging gardens decorating the walls of the building. I've learned that these hanging gardens were very challenging to design and build, requiring special planter boxes, each with its own irrigation system, supported by floor slabs in such a way that the plants can grow without disturbing the building's walls. A special mix of soil was used in the planter boxes.
As well, there are vertical green wall panels attached to the building. Creator, French botanist Patrick Blanc, insisted that plants could grow on these panels as long as they had something to attach to. There are three layers in the green wall: one of PVC and two of felt. In the outer felt layer, pockets were cut so that plants could be inserted and stapled in. The plants were tested in a wind tunnel to ascertain their suitability for this project as they have to able to withstand gusty wind, high temperatures and humidity. It's hydroponic gardening, and water and nutrients are delivered artificially to the panels from within the building.
In all, there are about 350 species of plants on the walls, some of which are quite rare: a variety of both exotic and native plants, and mosses. The idea for many of the native plants came from the vegetation found around the Wentworth Falls area in the Blue Mountains west of Sydney. Patrick Blanc said, “the vertical gardens will appear like a natural cliff as though [one has] cut a giant slice of the Blue Mountains and put it in the middle of the city.” Over time, microclimates have developed on the panels.
I was outside this building a few days ago and gazed with great pleasure upon it, admiring the lush greenery on its walls and the panels soaring up 33 storeys. It was a grey and rainy day, so in the photos the building appears somewhat sombre, but no matter, I'm sure that even though a bright blue sky is missing, the benefits of this building are apparent: a building that transcends the usual concept of a city building, and brings the benefits of greenery, gardening and nature to the city dweller.
Have you experimented with a green wall? Or seen a wonderful example somewhere? I would love to hear about it.