Land-scarce Singapore ranks among the top three most densely populated countries in the world. As it prepares for further population growth, the city-state is exploring new strategies to address overcrowding.
By Joelyn Chan
With 724.2 square kilometres of land and a population of 5.6 million people, space is at a premium in Singapore. With limited options above ground, the nation’s Draft Master Plan 2019 featured plans to construct below ground to combat overcrowding.
The Urban Redevelopment Authority will use 3D technology to map the underground spaces in the pilot areas, of Marina Bay, the Jurong Innovation District and Punggol Digital District. The sub-terranean developments will include data centres, utility plants, bus depots, a deep-tunnel sewerage system, warehousing and water reservoirs.
Singapore is one of the most densely populated nations on the planet
According to the World Bank’s population density statistics, Singapore has 7,953 people per square kilometre of land area. Only Macao and Monaco report higher populations per square kilometre with 20,778 and 19,196 respectively.

10 years ago, the city-state’s population density was just 5,900. An influx of foreign workers entering Singapore’s private sector drove the country’s population growth.
Without natural resources, Singapore relies on its human capital to drive economic growth. To compensate for its declining fertility rate and ageing population, the city-state has permitted the non-resident population to balloon.
The majority of the non-residents are work permit holders, who work in labour-intensive sectors. They take on less favoured jobs, building the nation’s skyscrapers, or working in service lines. Without them, Singapore would struggle to stay relevant in the increasingly cost-competitive region.
By 2030, Singapore’s total population is projected to hit between 6.5 million to 6.9 million people.

To mitigate the worst economic and social impacts of overcrowding, the Singaporean government has taken steps to reduce congestion during peak hours and in central business district areas.
Train operator, SMRT offers discounted journeys for early commuters. The government has also developed more working spaces outside the central business district as part of its long-term strategy to ease overcrowding.
Singapore goes higher, wider and deeper
As part of Singapore’s strategy to expand land resources, Singapore built taller buildings and underwent more land reclamation. Public housing flats can go as high as 48 floors up. Since the start of reclamation works in 1822, Singapore’s land area has increased by roughly 25%.
Now, the focus is on building deeper. In 2014, Singapore built its first underground oil storage facility, which frees up 60ha of usable land. Named Jurong Rock Cavern (JRC), it is also the first of its kind in Southeast Asia.
The first phase of JRC cost S$950 million (US$690 million). The cost is justifiable. With an additional 60ha of space, Singapore could build another six petrochemical plants if it wanted to.
Moving plants and storage facilities below ground also frees up areas on the surface to build more green spaces, which would help to reduce the perception of overcrowding.

Singapore’s Urban Redevelopment Authority (URA) is tasked with the challenge
URA will face an architectural challenge as it tries to push limits and build deeper. Theoretically, there is unlimited underground space for expansion. Hong Kong’s underground caverns, for example, are vast and are used for storing sewerage, housing utility plants and data centres.
Deciding what to build underground is not an easy decision. Once constructed, it is difficult to redevelop the underground area. Additionally, building underground is generally more expensive and complex. This is especially so for Singapore’s challenging geological composition – soft clay and rocks.
Singapore intends to take Hong Kong’s lead and shift non-core facilities underground. According to Mr Ler Seng Ann, group director at URA, “Currently, our focus is on using underground space for utility, transport, storage and industrial facilities to free up surface land for housing, offices, community uses and greenery, to enhance liveability.”
If Singapore succeeds in its pilot, land scarcity could become a problem relegated to the past. It will join Hong Kong, Helsinki, Montreal and Tokyo in building their underground futures.