By 2050, the urban population will nearly double to 6.3 billion—two-thirds of all the people on the planet. Cities are gaining 77 million new residents each year, equivalent to the population of Turkey or Germany, and twice that of California. Much of this growth is sprawl. Over the first three decades of this century, the global increase in urban land cover is expected to be greater than all urban expansion so far in human history. Urban centres ranging in size from 500,000 to 10 million residents will continue to evolve, putting land in these high-density areas at a premium.
Underground construction is creating new opportunities and approaches to sustainability to address those realities. The potential economic, environmental and social impacts of underground construction are immense, with proper planning and development of underground space promising enhanced quality of life in compact, efficient and sustainable cities.
Key trends point to the growing recognition of underground’s possibilities, of future integrated cities where underground facilities link-up with infrastructure and make life above ground more enjoyable.
A previous WSP report focused on rail overbuild and the societal benefits that can accrue from creating new residential accommodation by decking over new and existing railway infrastructure. This can include rail/underground tracks and stations. Here we put the case for underground construction as a spatial asset that extends beyond transport tunnels and utilities to a host of facilities currently occupying surface space.
However, we must start planning for the underground city now if we are to maximize the livability and continued functioning of our increasingly congested, high-density cities.