Incorporating more greenery into the public realm isn’t a new concept but we believe a bold change in thinking among public bodies is needed if the UK’s towns and cities are to become genuinely sustainable. Indeed, maybe even a new vocabulary is required.
Few would disagree that more could be done to make the public realm greener and more sustainable. What’s needed, however, is a shift upwards in terms of our collective expectations and ambition. The variety of ways that there are to ‘green up’ our public spaces is tremendously exciting, but that excitement means little if it’s not transmitted to local authorities, NHS Trusts and other public bodies which play a prominent role in shaping our urban environment.
Sustainable features should no longer be viewed as ‘add-ons’ to good design; they should be an integrated part of that good design. Our shared urban infrastructure shouldn’t be given a veneer of green respectability; those green credentials should be incorporated into the way in which that infrastructure is designed, built and used. We need to stop thinking of ‘infrastructure’ on the one hand, and ‘green features’ on the other. And that’s why I believe the concept of ‘greenfrastructure’ is critical to shaping the debate over the future appearance and long-term viability of our large towns and cities.
Public buildings and streetscapes can be transformed through living walls, green hoardings and other innovative greenfrastructure being more widely deployed on public buildings, as well as commercial and residential properties. These vertical items of greenery have an array of positive effects, from purifying the air to promoting biodiversity. They can even bring about a dramatic change in the way we think about food production, through the introduction of vertical allotments and ‘edible walls’. Thinking laterally about sustainability, it can often mean thinking vertically.
Through the wider use of such greenfrastructure, green corridors can be created that link open spaces and parks, thereby further reducing pollutants and promoting public health and wellbeing. It is no exaggeration to say that, if applied broadly, the use of greenfrastructure could bring about something of a green revolution on the UK’s streets – a far-reaching transformation of our urban environment.
By embedding the term ‘greenfrastructure’ in the debate over urban design, the public realm can be put on a firm sustainable footing. Ultimately, this isn’t just for the good of public sector bodies and their environmental targets; it’s for the good of the local populations they serve.
But what exactly are the particular benefits that green screens, living walls and other items of vertical greenfrastructure provide? As touched on above, one of their primary functions is to make the air cleaner. The herbaceous plants and other vegetation of which the walls and screens are comprised absorb particulate matter (PM10s) and release oxygen through photosynthesis. The importance of this in congested urban areas cannot be overstated.
A number of academic studies have pointed to the respiratory illnesses and deaths that are caused by polluted air, and the UK is certainly no angel when it comes to air quality. Last year the European Union ruled that the UK was in breach of its air quality directive. Moreover, 16 areas of the UK are forecast not to meet the EU’s legal nitrogen dioxide limits by 2015.
Encouragingly, a number of local councils and the Mayor of London, Boris Johnson, have already shown an appetite for tackling this respiratory danger by introducing greenfrastructure. But air purification is not greenfrastructure’s only virtue.
Health is not only to be measured in physical terms, but in mental terms too. And there is an increasing body of data that points to the importance of greenery and green space in enhancing a sense of wellbeing.
Earlier this year, academics from the University of Exeter’s European Centre of Environment and Human Health published a study in the journal of Psychological Science that examined the relationship between urban green space and mental wellbeing. After considering the self-reported psychological health of individuals over time, the study suggested that people are happier when living in urban areas with greater amounts of green space. “Findings show that urban green space can deliver significant benefits for mental wellbeing,” concluded the scientists.
Of course, in some urban areas, it is simply not possible to conjure up a lush park – there is too much concrete. So when historical developments mean there is little green space available, local authorities need to devise ways of incorporating greenery into the existing streetscape. And this is where vertical greenfrastructure has a vital role to play.
The health benefits of a more widespread, comprehensive use of greenfrastructure are therefore considerable. And it is also the case that greenfrastructure is good for species other than humans. Biodiversity is promoted through the introduction of green screens and living walls; a not unimportant consideration given the frequently reported plight of the bumble bee and the resulting impact on pollination.
In addition to their environmental and health benefits, living walls can also give an area an aesthetic lift, which in turn can bolster community pride and cohesion. Inner cities needn’t be areas that are bereft of nature’s sense of beauty and calm. Depending on the plants chosen for the panels of a living wall, greenfrastructure can change with the seasons and provide a varied, stimulating landscape for both the inner city dweller or passer-by to enjoy.
Living walls can also deter the scourge of many urban areas: the graffiti vandal. Plants that are selected for their all-year-round appearance and hardiness can be a powerful deterrent because they deprive the graffiti artist of his canvas – a blank wall. On top of saving local councils money on expensive wall-cleaning bills, greened-up buildings can reduce levels of vandalism because they foster a sense of collective pride in an area.
Energy savings can also be made through the wider application of greenfrastructure, with the plants in the wall functioning as a blanket to mitigate heat loss from the building in winter. Conversely, through evapo-transpiration, the same coverage of vegetation can sharply reduce the need for additional cooling in summer. University studies have provided corroboration of this.
Moreover, when well designed, the maintenance costs of a living wall can often be offset through the energy savings that it provides. Green walls can protect a building from UV, weather and temperature fluctuations and thereby extend the life of a structure.
Greenfrastructure also has the power to revolutionise the way food is grown. If the sides of public buildings can be turned into vertical allotments, then a whole new dimension opens up in the way that fruit and vegetables can be grown. ‘Edible walls’ – walls that enable herbs and small fruits to be grown – are already a feature in a growing number of residential gardens. Why not in public spaces too?
Enfield Borough Council in London is one authority that has shown itself keen to do this. The council has embarked on regeneration work around Ponders End High Street, an area affected by the 2011 riots. While work takes place, a green hoarding has been erected around the building site. In order to ensure community ‘buy-in’, the council has left space for a community hoarding where local residents can plant and grow their own plants and fruits on their high street. It is a project that shows that barriers to gardening in an urban area can be overcome.
Elsewhere, Guy’s and St Thomas’ NHS Foundation Trust is showing how greenfrastructure can be incorporated into its estate. The trust has installed an ivy hoarding around the building site for its new King’s Health Partners Cancer Centre, which will open in 2016.
As well as improving the appearance of the construction site, the green hoarding is in keeping with the trust’s sustainability strategy, reducing its carbon footprint and improving air quality for patients, staff and the local community.
There are examples, then, of greenfrastructure becoming part of public bodies’ thinking. The important task now is for the word to be spread so that such sustainable initiatives become an ordinary aspect of inner city development. Should that happen, then a genuine transformation of the urban environment can be brought about, for the good of us all.