Scientifically proven: Vertical Gardens® improve air quality

blowUP media has now scientifically proven the impact of its Vertical Garden® “The Green – A40 Hanger Lane” in London – thereby empirically confirming what specialist literature and practice have long suggested: green façades make a measurable contribution to improving urban air quality.

The aim of the study was not only to use theoretical values from specialist literature, but also to collect real measurement data under everyday conditions and thus empirically prove the effect of Vertical Gardens® on harmful nitrogen oxides (NOx).

The Green – A40 Hanger Lane covers an area of over 130m² and is planted with 6,350 plants of various species. The site is located on one of London’s busiest arterial routes, where air quality is particularly poor. Traffic-related air pollution is a major problem in cities because it increases health risks. Nitrogen oxides (NOx), which come mainly from car exhaust fumes, irritate the respiratory tract, promote inflammation and can contribute to cardiovascular disease in the long term.

The study was conducted between March and August 2025 by Dr Jan Serode, architect and recognised expert in innovative façade systems in urban areas. It was carried out in cooperation with a renowned German research centre for the laboratory analyses and technology partners AQMesh (UK) and passam ag (Switzerland), who provided the measurement technology. The three-stage approach – laboratory tests on individual plants, measurements with digital sensors, and measurements with passive collectors on site and on an unplanted control façade – provides a consistent and reliable overall picture.

The study results are clear: on all measurement days, NOx pollution in front of the Vertical Garden® was significantly lower than at the control site without vegetation, by an average of 28% and during rush hour by as much as 30–50%. In addition, laboratory analyses show that the plants used can absorb relevant amounts of nitrogen dioxide. Extrapolated, the Vertical Garden® filters 8.8g of NO₂ per day. The study thus confirms the ecological effectiveness of such green façades at highly polluted traffic junctions.

“The study is convincing thanks to its scientifically sound methodology. Instead of relying solely on theoretical assumptions, blowUP media had the impact of the Vertical Garden® precisely measured. This is particularly relevant because the effects of façade greening have not yet been sufficiently researched. It is an important step towards better understanding their actual environmental benefits and developing them in a targeted manner,” says Dr Jan Serode.

In our Best Case, we have summarised the most important data and facts from the study in a compact format.

The Green – A40 Hanger Lane is part of blowUP media’s steadily growing portfolio of Vertical Gardens® in Europe. At all sites, we pursue the same goal: to combine large-format outdoor advertising sites with ecologically effective façade greening – thereby bringing together brand communication, sustainability and urban transformation. The study underscores this approach with clear data and shows that Vertical Gardens® offer cities a measurable environmental benefit and brands an authentic stage for sustainable engagement in public spaces.