Greening Grey Infrastructure:
New NERC guidance aimed at improving uptake

IGGI reportGreen infrastructure (GI) is widely known as a sustainable and cost-effective way of managing key environmental issues in cities and towns. One area with little attention has been, “How do we green the parts of our cities and towns that need to remain grey for their primary function like seawalls, pavements and bridges”. This is called ‘integrated green grey infrastructure’ (IGGI) – that is, greening the greyest parts of our cities and towns that must remain largely grey for their primary function.

In the last 18 months a team of UK partners and project advisors supported a Natural Environment Research Council funded Green Infrastructure (GI) innovation project designed to address this gap. We created a decision support tool and a directory of examples.

With guidance from leading environmental economists, the wider ecological, social and economic benefits were included, and broader business cases were made for greening grey infrastructure across 4 landscapes – urban, mown, historic and coastal/estuarine.

The results represent:

How can you use the report?

This tool can be used to help you make the case for green grey approaches by:

What are we doing next?

We are working closely with several national government agencies, local authorities and businesses to help embed the green grey concept in policy and practice.

How you can get involved?

We are really keen to get your feedback and to share this work with you. If you are interested in finding out more or would like to deliver a training workshop please contact: or

More detail on the method

The method used for valuing green grey compared to grey can be found in Naylor et al. (Sept) 2018. Developing a business case for greening hard coastal and estuarine infrastructure: preliminary results. Coasts, Marine Structures and Breakwaters 2017, access via this link.

Footnote: The project was led by the University of Glasgow in partnership with the University of Oxford and a suite of government agencies and companies across the UK. Three established UK companies and industry-bodies are also involved in this project (HR Wallingford, MWH Global (Dr. Bruce Horton) and CIRIA) to ensure industry relevance. Advisory Board and Supporters: Glasgow City Council, New York City Parks Department, Southampton City Council, ARUP, University of Kent, Heriot Watt University, University of Strathclyde, Environment Agency, Natural Resources Wales, Historic Environment Scotland, The Scottish Environmental Protection Agency and Historic England.