Should we be encouraging green walls within cities?

This week, plans were unveiled for a 36-storey tower within the City of London. The building has been designed by Eric Parry and will consist of a 60,000sq m building, and a public viewing platform with the main feature being a huge vertical green wall spanning the entire external façade. Plans are set to be submitted soon and if approved it is set to be the UK’s tallest ‘hanging garden’.

The application follows plans for a new hotel, also submitted to the City of London last week. The 10-storey hotel will have 382 bedrooms and the largest living green wall in Europe with over 400,000 living plants and a living meadow on the roof and will be located next to St Pauls Cathedral. Not only is it an innovative design, the proposed green wall is predicted to absorb 8 tonnes of the city’s emissions, release 6 tonnes of oxygen and reduce the temperature by between 3- 5 degrees!

Green walls reduce air temperature, lower air pollution, purify the air by reducing dust and fuel emissions and release oxygen, as well as act as sound and heat insulators on buildings. Studies have also shown that green walls help to reduce stress and anxiety and provide a sense of well-being. They also provide the opportunity for crucial biodiversity in the heart of cities, where space tends to be more precious and limited.

The use of green walls and ‘vertical forests’ within cities has already proven successful in reducing carbon emissions, such as the renowned 'Bosco Verticale' in Milan, which was built in 2015 and is home to 730 trees and 16,000 plants on two residential towers, creating a biological habitat of around 40,000sq m. Vertical forests help to lower humidity, take in CO2 and produce O2, creating micro climates, as well as new habitats for wildlife, flora and fauna. 

The use of green walls within development should be actively welcomed in terms of their proven positive climate impacts. However, green walls can have a number of concerns for councils and developers. A green wall is ‘living’, so it is constantly changing. The type of plants proposed is a key factor, as it establishes the look of a building throughout the seasons. Also, the cost of maintenance of green walls will be high so it begs the question – is this something developers will want to adhere too?

In a time when we are having city wide climate change protests and Extinction Rebellion are campaigning to reach zero carbon targets by 2025, we should be looking at all options to help transform developments in both the sense of pioneering design and helping to lower our country’s pollution targets. So, when climate change is the hot topic, temperatures are rising and air pollution is worsening, could green living walls be a short-term answer to our growing climate issues within our major cities?

Georgia Goff, Planning Assistant