Green walls offer greater potential for absorbing noise. This is according to an agricultural engineer from the University of the Basque Country.

Zaloa Azkorra, who is conducting research at the University’s School of Mining and Public Works Engineering into the benefits provided by green walls, has concluded that walls comprising plants offer great potential for absorbing noise and could be used as acoustic insulation.

Azkorra conducted a noise absorption test which was carried out in a reverberation chamber, which consists of a chamber with walls that are fitted with materials that reflect noise of the same type in all directions, using a range of frequencies.

The test found that green walls perform very well in high as well as low frequencies with respect to noise reduction, whereas other materials used in buildings only perform well at either high or low frequencies.

The way green walls may behave as acoustic insulation was also studied and plant modules were fitted onto a laboratory wall and the level of noise insulation was measured.

The conclusion reached was that with some slight improvements, like increasing the mass of the modules or covering the space between them, the system can be made more effective and, as a result, the green walls could be suitable for acoustic insulation.

Azkorra believes that green walls could be beneficial in the future to offer a greener image of towns and cities, to improve the life quality of citizens, to save energy, to increase biodiversity, to control rainwater, to lessen town/city noise and to minimise waste and pollution.

She is currently taking her research a step further and conducting thermal studies on the green walls.