Developing underground space: a view from Singapore

What are the essential elements to realizing the full potential of underground development?

Cheryl Lee: There are several key factors. Effective planning is the starting point of the process. In 2014, the Urban Redevelopment Authority of Singapore commissioned an underground survey to support the efficient and coordinated use of Singapore’s underground resources. The continued and efficient use of underground space requires the Singapore government to develop comprehensive regulations that effectively guide the use of underground space.

An integrated master plan is essential, which requires coordination and inclusion of government and private actors, as well as the public, especially to properly connect underground infrastructure to existing surface infrastructure. These steps also apply to underground development worldwide.

Underground construction involves its own set of safety considerations. Of course, technical expertise is another necessity. The cost of construction is a major factor; underground construction is generally more expensive than surface construction. However, with the introduction of advanced technologies, underground excavation can become safer, faster, cheaper and more easily achievable.

It is difficult to overestimate the value of good underground space use planning, given the social, environmental and economic impacts of use. It is also important that governments and institutional leaders have the financial capacity to fund underground construction. Feasibility studies and cost-benefit analysis help identify key cost and time savings, as well as areas where productivity can be improved during the construction phases.

Can you explore the potential impact of underground development on Singapore’s central business district [CBD]?

Cheryl Lee: Singapore’s CBD consists of new and old buildings, skyscrapers and preserved buildings, along major roads with frequent traffic and pedestrian travel – very densely populated areas.

It is important to keep in mind the potential impact of underground development on CBD during construction. This is where the necessary factors discussed earlier come into play, such as the safety of underground construction and the entire site to ensure that ground settlement is well controlled to prevent damage to surrounding buildings. Detailed damage assessments would also be required and conducted to ensure existing CBD buildings within the compound are maintained in a safe and usable condition.

Underground development can certainly have a positive impact on pedestrians; underground networks provide convenient and seamless connections between transportation facilities, key spaces and attractions, and the benefit of all-weather comfort.

How can the experience of the pandemic inform the planning and design of underground spaces?

Cheryl Lee: The pandemic has radically changed lifestyles. We now rely on technology to enable people to work from home, students to learn from home, and people to take care of their everyday purchases online, such as banking and grocery shopping; almost anything can be done at home without having to step out of our front door. But it is also important to consider what communities want urban places to provide – their purpose – and how infrastructure can support more livable cities.

Safe distancing and other measures to create healthier environments, both above and below ground, will continue to be considered in our designs. For example, the entire underground ventilation system could be improved to reduce the spread of viruses and airborne contaminants. All common touch points and common surfaces must be covered with a self-disinfecting coating. Public toilets in the underground space should be specially designed with improved hygiene. These steps, which also apply to above-ground infrastructure, can go a long way towards designing spaces that support the health and well-being of people in the underground environment over the long term.

For the future, what are the possible uses of the underground space?

Cheryl Lee: The current use of underground space in Singapore reflects functionality and adaptation to human activities. In the future, there are many possibilities such as agriculture or urban agriculture through hydroponics. Other potential areas are laboratories, light industrial factories, data centers and swimming pools.

We also need to think about how we can maximize the value and use of these underground spaces. For example, an underground farm can be designed for a secondary purpose by functioning as a public park; underground car parks can also be used as driving schools or for recreational purposes such as a go-kart track; facilities that can accommodate large capacities – theatres, concert halls or sports stadiums – can be set up underground, freeing up more land on the surface.

As I mentioned earlier, this is a pivotal time to influence and set an appropriate course for sustainable development in Singapore. Although we have some regulations in place for underground development, given the goals of the recent COP26 [2021 United Nations Climate Change Conference]the big question is: how can we do more with underground space and move towards net zero carbon emissions?

1 “The remarkable history of Dutch polder systems in the Netherlands”, Food and Agriculture Organization of the United Nations (FAO), 2010
2 Charting Singapore’s Low-Carbon and Climate Resilient Future, National Secretariat Climate Change Strategy Group, Office of the Prime Minister, 2020

Bonny J. Streater