The Bosco Verticale in Milan are literally green tower blocks. The two tower blocks are home to over 700 trees, of which there are 90 species of plant! There are sooo many benefits to this, but these are the key ones:
Passive solar / thermal design – A deciduous tree during the summer has thick foliage, providing shading. If designed well, and integrated into the overall building’s design the trees could reduce strong glare and overheating during the summer months. Equally during the winter months, when the weather tends to be more overcast the lack of leaves allows much more light and heat to enter a building. This ultimately reduces the need for lighting and air conditioning / heating.
Water use – If there is a cohesive building wide strategy for water use, including biodegradable shower and cleaning products then there is no problem with using waste water from the sinks and showers (alongside rainwater) to be integrated into an irrigation system within the building. If you were really organised you could even integrate composting toilets into the apartments allowing solid waste to be turned into compost and urine to be diluted in water to create fertiliser. Although perhaps not to everyone’s taste, it does further reduce our impact on the earth.
Acoustics – Planting has been used for decades within design as an effective acoustic barrier. Imagine living in a city where there is so much natural planting that even in a skyscraper there’s only a faint sound of the roads beneath you.
Air quality – Plants reduce CO2 levels and increase O2 levels at a basic level, however they can be far better filterers than simply this exchange through photosynthesis. A study by the Nature Conservancy in America found that “planting 1,000 acres of native trees, primarily American and cedar elm, green ash and sugarberry, could remove as much as 209 tons of nitrogen oxides from the sky over 30 years. That’s the equivalent of taking more than 800 cars off the road annually.” This study obviously took place in America, but I wonder if native UK trees might have similar effects.
Bees! (and other insects) – Many people are aware that as a result of reduced biodiversity, and increased use of pesticides within farming we have a great reduction in insects that rely upon flowering plants to survive. This also has a knock on effect on plant species that rely on pollination, and also the other animals that might eat these insects. If planting is focussed on native trees and flowering plants there could be a massive increase in wildlife within our cities. Imagine if this was considered with a city-wide greening plan, and the buildings linked up with parks, possibly providing green strips of land throughout the city. Oh, I can dream!
Food production – You could easily integrate in edible plants and vegetables into the design. Trailing tomato vines off balconies, including herbs such as a bay tree or lavender, or planting carrots and parsnips beneath larger trees and shrubs. There are so many books written about producing food from small spaces, including a few of my own shown here:
This is a great example of exactly why a design team must be so well integrated throughout the design process. For this design to work architects, engineers and horticulturists all have to work together.