The conundrum of Green Infrastructure and Urban Development

The Landscape Institute recently hosted a biodiversity seminar entitled “Nature, People and Place: Why we must build for biodiversity”, presented by Dr Phoebe Carter, Habitat First Group’s chief ecologist. Dr Carter set out a comprehensive list of actions to take when building for biodiversity, which were backed up by some inspiring case studies. These included a number of developments on old quarry sites where the layout was designed around existing biodiversity and landscape features; informed by the wider landscape context and character; created corridors of connectivity and incorporated SuDS within areas of soft landscaping. During the talk it struck me how complimentary the principles of designing for biodiversity are with the aims of good green infrastructure design generally and a landscape-led masterplanning approach. This is the way in which landscape architects and masterplanners seek to design.

However, as the Q&A session that followed made apparent, this approach of net biodiversity gain is very much applicable to large scale, rural sites with relatively low density - and in these examples, luxury holiday homes -, and is difficult to apply effectively in urban areas. Net biodiversity gain in urban areas is typically delivered offsite. Similarly, small scale projects and projects in existing urban areas can seldom deliver integrated green infrastructure on their own. The public realm of smaller and infill sites require existing connections, features and infrastructure to plug into. Small sites have far less flexibility and capacity to accommodate existing features and limited space for less engineered solutions to constraints such as level changes and drainage. Typically, small sites do not generate a requirement for open space or play given their low housing numbers, and once again open space provision is provided as an offsite contribution.

Whilst infill sites are an important part of the regeneration of our towns and cities, in order to achieve many of the principles of good design, biodiversity gain and positive placemaking, sites of sufficient scale are required. All too often, towns and cities are delivering housing year by year in small quantities, focusing only on the housing need of that particular 5 year period. Without a larger green infrastructure strategy or broader masterplan for an area of growth, these small-scale pockets of housing do not contribute to the wider connectivity, open space and biodiversity objectives.

Local authorities incorporate green infrastructure strategies into their Local Development Plans (Scotland) / Local Plans (England) to a greater or lesser extent, which can inform layouts coming forward. However, they are one of many considerations for assessing an application and when balanced against viability and the need for housing can be set aside all too easily, or delivered in a tokenistic manner that misses the wider opportunities that they represent.

It remains to be seen how the proposed changes in England set out in the Housing White Paper will be manifest post consultation, how they will seek to achieve net gain, and what that requirement will encompass beyond biodiversity. This will be even more critical in urban environments where densities will be increased through the re-use of brownfield land, making Green Infrastructure even more essential but ultimately more challenging to deliver.

The challenges are clear, but what is also clear is that the importance of Green Infrastructure and its intrinsic value is becoming better understood at all levels – from the households, who have been through lockdown and are embracing or powering through homeworking, to the developers and policy makers, who are in a position to identify the added benefits and value (financial, social, ecological) of well-designed Green Infrastructure.