Houses dressed in cascading branches and leaves usually make us think of decay; buildings that have been neglected and abandoned, or ancient architectural ruins long since swallowed by the surrounding environment. But vertical gardens are something that can now be seen in our cities and urban spaces more and more.
In the last decade however, the global quest to halt the warming of our planet has given new wind to an idea famously championed by Italian architect Matteo Thun in the 1950s - the renewed connection between humans and nature.
Living walls or vertical gardens are emerging as a carefully calibrated attempt by architects and designers to solve many of the most pressing urban issues of our time.
At the top of that list is the rapid warming of our cities.
This is all thanks to the heat island effect - where buildings and roads absorb the sun's energy and release it well into the night - urban areas could warm as much as 4.4°c by the end of the century. While that might not cause massive problems to someone living in northern Canada, it will have an especially devastating effect on city residents on more southern latitudes, including respiratory difficulties, cramps, exhaustion and even heat-related deaths.
Architects are now touting plant-covered facades as a solution beyond merely cooling individual buildings, but to also lower the temperature of entire urban areas. And of course, in every major city there are millions of square metres of empty walls and roofs that could be transformed into forests and lush, towering fields.
If implemented on a large scale, Babylonian design would drastically change our existence: beyond keeping us cool, millions of plants would become the cities "lungs", cleaning the air while providing fresh oxygen. It would absorb the noise pollution from the clattering of a busy street and sound-proof our homes and offices. It would increase biodiversity by providing habitats for nesting birds and pollinators. And, it would improve the mental wellbeing of urban dwellers.
So, if the benefits are so plentiful, why haven't we turned our cities into green oases already?
While ambitious projects are underway from Singapore to London, from Amsterdam to Sydney, biophilic design is still in its infancy with some architects questioning the viability of turning cities into meadows:
- What will be the commercial impact of creating vast and robust vertical fields that need the same maintenance as major parklands?
- Can we build sustainable irrigation systems?
- Can vertical gardens withstand extreme weather conditions like storms?
- Will all greenery come with a scourge of mosquitoes and other bugs?
Indeed, important questions still remain. But we should also remember that other environmental solutions were also marred by skepticism before reaching a tipping point. Experts across the globe said solar energy would never become commercially viable - today it's the cheapest form of electricity in many countries.
To thun, the Italian architect, a renewed connection between humans and nature represented a "return to normality". Today of course, that phrase has acquired both new meaning and urgency as "normality" means limiting the warming of a planet that is heading towards destruction. Should the introduction into living systems into architectural design become a central part of the solution, the future city might not look like a scene out of the Jetsons, but rather look more like Indiana Jones.
The potential of merging urban life with nature is one of the topics we discuss in our latest episode of Rudi Scheuermann. Specialising in building envelope design, Rudi is the "green hand" of Arup - the multinational firm at the forefront of some of the world's most ambitious and challenging design and engineering projects.