The features of London’s current housing shortage are by now well known: rising house prices; housing estate regeneration, garden city proposals. The struggle to increase housing supply is inherently linked to the high building costs in the city, with London topping the list of most expensive cities to build in. The reasons behind these high costs are explored in this recent video from The Economist. Despite the city’s relatively low density relative to its size, building in the city requires considerable resources. The city’s historic infrastructure, including networks of tunnels, ruins and medieval roads all contribute This video from the Economist reveals how these high costs arise thanks to the city’s historic infrastructure. Vast networks of underground tunnels, unexploded World War II bombs, ancient Roman ruins, and narrow medieval roads all contribute to the complexity of construction in the city. Despite these cost factors, development continues to thrive and the city continues to gather influence as a finance and tech capital, as evidenced in the recent announcement of London as the world’s most influential city.