Investing in urban underground space: maximising the social benefits

With increasing pressure on space in cities, we are seeing greater development underground. Despite the multiple benefits of underground space, its social value is underappreciated and no market for underground space utilisation exists. The result is that underground space is not planned, engineered or managed in a way to realise its potential value. This paper presents findings from a Think Deep UK initiative which explored the social value of underground space and evaluated the UK’s Social Value Act which embraces social, economic and environmental benefits. It was found that the main drivers to evaluate social value for infrastructure projects are cost and risk which are intimately linked with the scheme’s design life. As such, only tractable, evidence-based benefits are easily accounted for. It is suggested that social value frameworks should be flexible and incorporate qualitative measures of value across different timescales so that long-term benefits for future generations are planned.