Climate change and the need to connect with nature is driving demand for living walls. Here, Richard Sabin of Biotecture, looks at how they have already changed the way we design buildings
We all live in an increasingly urbanised world with around 84% of the UK population living in built-up areas, according to United Nations population studies. The government is already taking steps to address the issues that this creates with the Environment Bill. When it becomes law, it will be obligatory for new developments to protect and improve the biodiversity of the plot by at least 10%.
This means developers need to prove biodiversity net gain (BNG) to receive planning permission. One effective way of doing this is to incorporate living walls, which could contribute to helping demonstrate BNG. Although the Bill is still going through Parliament, some forward thinking local authorities already insist on biodiversity net gain for new developments.
This Bill is set against a background of climate change and the government’s 2050 net-zero carbon target, which are key reasons why urban design needs to change. If we are to design and inhabit truly sustainable urban landscapes that are fit for the future, we need to retain and strengthen our connection to the natural world.
Tackling climate change
Here are three ways in which architects can utilise living walls to help mitigate climate change and reconnect people with nature.
Building bio membranes.
The urban heat island effect is a growing concern for policy makers. We’ve all experienced it when visiting a city on a hot summer’s day and can feel the heat emitted from the pavement and building facades.
Climate change will exacerbate this problem, with studies by the Swiss Federal Institute of Technology predicting that London will have a climate similar to Barcelona by 2050. The challenge is how to mitigate these impacts and this is where increased biophilia plays a crucial role. Plants within living walls provide natural shade and absorb heat, which can be seen from this thermal image in London. The building on the right has our living wall (cooler), whereas the building on the left shows elevated façade temperatures.
This is important because of the sheer number of people living in our cities. Placemaking involves creating quality places that people want to live, work, play and learn in. A key aspect of placemaking is providing natural spaces for people to re-connect with nature. Being close to nature provides us with a sense of wellbeing and when space is tight vertical greening is an efficient option.
An example is our living wall that was specified by Willerby Landscapes for Land Securities’ 20 Fenchurch Street. The aim was to create an environment surrounding the retail cafe area that was both pleasant and impressive. The wall creates functionality and interest on an otherwise unused service building wall. The project also contributed to the design team’s sustainability goals, helping the building to achieve a BREEAM ‘Excellent’ rating.
This refers to the power of nature to help mitigate and reduce the concentrations of contaminants in the environment. We recently worked with Balfour Beatty Living Places to install air pollution-busting ‘green walls’ on a busy roundabout at the gateway to Southampton. Hydroponic living walls are vertical installations which feature living plants and foliage that grow without needing soil. The structures absorb air pollutants such as carbon dioxide (CO2), sulphur dioxide (SO2), nitrogen dioxide (NO2) and particulate matter. The project is a UK first and was delivered on behalf of Southampton City Council. It recently won a Green Apple Gold Award and is maintained by Biotecture.
Phytoremediation delivers important physical benefits and we are taking these to the next level by developing a system that draws air through roots of plants and then returns clean air back into back into the environment. In doing this it can break down nitrogen dioxide and capture Particulate Matter. When deployed indoors it can control air flow and, ultimately, we would like to see it replace energy intensive ventilation systems and air handling units. It could work just as well as outdoors, creating clean air zones and the proven health benefits of clean air.
Climate change and demand from clients for greater diversity means that more architectural practices are looking for ways to incorporate green infrastructure into their designs. This is happening at early design stage and that is encouraging because it means that biophilic design is engrained into the project from the start rather than being introduced at later stages.
The signs are good for the future. Plants should be viewed as a vital element of design for the welfare of human beings. We can also learn from other countries. For example, some German cities will pay 50% of the value of green infrastructure to encourage its use and that is kickstarting a green revolution.
We all want our urban spaces to be places where people can thrive and so it is a win-win when we can say that living walls do this whilst tackling climate change. Nature needs to be more prominent in design as more people live in urban areas. The move to net zero and the Environment Bill will drive this agenda. We can see there are challenges but also with it, immense opportunities to revolutionise the design of our urban areas.
For more information of Biotecture living walls, visit: www.biotecture.uk.com
Richard Sabin is managing director of Biotecture