Singapore's stellar growth has seen skyscrapers spring up everywhere, even on the sea, but plans now look underground for new spaces to occupy.
Singapore's goal has always been to manage dizzying population growth without making the same mistakes as other Asian metropolitan areas, traffic and overcrowding in the first place.
Its population, currently 5.6 million, is growing at such a rate that, considering an area equal to half the city of Los Angeles, the authorities are considering the use of underground areas.
It is not a boutade
Singapore is no stranger to using underground to expand: has already built one extraordinary underground highway and a futuristic thermal conditioning system. The construction of new structures, however, would definitely go in the residential-working direction.
"We are considering the option of putting important infrastructure underground," says Abhineet Kaul, specialist and advisor to the finance company Frost & Sullivan.
"We have a strong need for industrial, commercial, residential and even green spaces".
According to a town plan launched last March, authorities intend to move industries, transportation hubs and underground warehouses to free up surface space.
For now (and I mean well) no forecast of underground residential areas.
Dig, dig, dig
Singapore is the most determined but not the first to seek new expansion spaces underground.
Helsinki, the capital of Finland, already has parking lots, shopping malls and underground swimming pools. Montreal in Canada has a real "sub-city", a system of tunnels connecting the key points.
A report commissioned by Samsung on the 'shape' of the world over the next 50 years includes the creation of "scratchers" among the remedies for overcrowding. Real skyscrapers planted in the earth, with fewer seismic problems and climate management based on geothermal energy.
However, the main method used by Singapore remains the "Dutch" one: plucking pieces of land from the sea. In recent years (since 1965, the year of independence) a quarter of the 720 square kilometers that make up the city surface, a quarter has been recovered from the waters.
A method that has become too expensive as the seabed has become deeper and less sustainable (many countries have stopped supplying sand to Singapore in order not to mutilate their lands excessively).
Advantages and disadvantages of the subsoil
Moving cubes in the subsoil has advantages on soil consumption and reduced use of air conditioning (which is very high in tropical climates such as Singapore).
The challenges are always the same: "Building underground requires crushing rocks, which is by no means easy to do under already urbanized areas," says Chu Jian, professor of civil and environmental engineering at Nanyang Technological University (NTU).
The next frontier
One of the most advanced underground projects in Singapore is a underground "refrigerant" system which pumps water into underground pipes to cool the surface temperature. The Marina Bay area has buildings "refreshing" from this cooling system similar to those found in our refrigerators, so to speak.
Buildings that use this centralized system reduce energy consumption by 40%, says Foo Yang Kwang, chief engineer of the SP Group, the company that carried out the project.
The savings also made it possible to cut emissions by around 34.500 tons of CO2, the equivalent of 10.000 cars taken off the road.
Did I mention theunderground highway 12km longest in Southeast Asia? To her they add the meter, a ammunition depot and caves used for fuel storage.
NTU, one of the largest training institutes in the city, plans to build WORKSHOPS and in the future also study rooms underground.