Greening the city with moss walls – A greener life, a greener world

By Jeremy Williams

In the Ashden offices in London there’s a living green wall in reception. It’s a tradition for new members of staff to have their picture taken in front of the moss wall.

Moss walls aren’t just for interior design talking points, however. A blanket of moss on an external wall serves as a sound baffle in a noisy city. It literally softens the urban environment, reducing the visual and sonic starkness of concrete and its angular surfaces. It improves air quality by catching windblown dust in the fibres.

Like all green walls, moss can play a role in water management. It slows run-off from buildings, holding and releasing water more slowly to prevent drains from being overwhelmed in sudden showers. When heat is the problem, moss helps to cool the city and reduce the urban heat island effect.

Each moss wall is also a miniature forest for tiny creatures, improving biodiversity. And of course, they’re nice to look at – bright and lush and textured. Hooray for moss, basically.

So how do we get more moss walls in our cities?

A company in the Netherlands called Respyre has come up with a technology to create moss walls and incorporate them into architecture more easily. It’s a combination of two things. First, you add a layer of bioreceptive concrete cladding to your wall. This is concrete with increased porosity, full of little holes and dimples that give the moss a place to send their anchoring rhizoids. Onto this concrete layer, you then apply a bio-gel that contains moss spores and the nutrients they need. This fast-tracks the natural processes that lead mosses to grow on walls and deliver a more consistent and predictable living layer.

It’s early days for Respyre, but earlier this year they moved from a series of pilot projects to a commercial launch. Their products are now available to designers and builders in the Netherlands and Belgium, including moss-welcoming roof panels and precast concrete wall panels. No word on the UK yet, but if you’ll pardon the expression, I hope it catches on. 

First published in The Earthbound Report.