Singapore can show Asean how to cool cities without air-conditioning

WHEN temperatures rise, our instinct is to turn up the air-conditioning. In South-east Asia, that response will become increasingly costly.

Energy consumption for space cooling is on track to more than double by 2050 at the current trend, and demand will rise as cities expand, living standards improve and heat intensifies.

Air-conditioning will remain essential, but efficiency improvements cannot be the whole answer. A more durable strategy is to reduce the amount of cooling a building or district needs in the first place.

In the tropics, where site conditions allow, orienting a building’s longer faces to the north and south can reduce exposure to the afternoon sun. External shading, deep overhangs and less unprotected glazing on east and west facades can further limit heat gain.

But thermal comfort is more than an environmental or architectural concern. It also influences whether people walk, use public transport, spend time outdoors or retreat indoors.

In a knowledge economy, the public realm is productive infrastructure: comfort shapes how far people walk, how long they stay outdoors and how easily ideas and commerce circulate.

Why walkability creates value

Walkability is sometimes discussed as though it simply means providing pavements in outdoor areas. In a tropical city, however, a route is not truly walkable unless it is shaded, ventilated, connected and useful.

Shade at street level matters. Ornamental planting cannot perform the same function as mature, broad-canopied trees. Tree canopies intercept solar radiation before it reaches pavements and walls. Through evapotranspiration, they also cool the surrounding air and reduce the heat absorbed by concrete and asphalt during the day and released after sunset.

Breeze and air movement must also be treated as infrastructure. Building spacing, height variation, ground-level porosity and the alignment of streets and courtyards shape whether prevailing winds reach the places where people walk and gather.

These are not decorative choices. Together, they can determine whether an outdoor space is usable for ten minutes or two hours.

When those conditions are present, the benefits compound. More people on foot create passing trade for shops and food businesses, raising tenant retention and asset valuation.

Occupied streets feel safer. Comfortable journeys encourage unplanned encounters among colleagues, researchers and residents. Public space becomes social infrastructure rather than leftover land.

This is especially important in innovation districts. Laboratories and offices house formal work, but collaboration often begins in the spaces between them. A comfortable courtyard, sheltered path or open plaza can act as a “social condenser”, bringing people from separate buildings and disciplines together, increasing productivity and innovation.

Climate-responsive design protects the qualities that make cities attractive: convenient movement, lively streets, social connection and a daily life not conducted entirely indoors. These conditions shape how people experience a city and, over time, help sustain its competitiveness.

A model for South-east Asia

Singapore cannot compete with other cities on the appeal of its climate; it will never be the naturally cooler option. Its edge must come from designing a tropical destination that remains pleasant despite the heat.

There is already a strong foundation. Marina South was planned using detailed wind-flow studies, with buildings of varying heights positioned to channel breezes through streets, public spaces and residential areas. The Urban Redevelopment Authority has published thermal analysis showing that lush planting can substantially lower surface temperatures in exposed areas.

The next step is to make climate-responsive design systematic and measurable.

Projects should be assessed not only on energy efficiency inside buildings, but also on outdoor thermal comfort, canopy coverage, shaded walking distance, wind performance and the hours during which public spaces remain usable. Post-occupancy data should then feed back into planning and design standards.

Singapore’s urban environment doesn’t only increase its appeal to visitors and talent. It can also serve as an example for South-east Asian cities grappling with heat.

A report published by the Asean Centre for Energy warns that major cities in the region could experience between 85 and 120 days a year above 35 degrees Celsius by 2050. It calls for a “passive first” approach: reduce heat gain through ventilation, shade, reflective surfaces and high-performance building envelopes before adding mechanical cooling.

Singapore can help turn that principle into practice. Its export would not be a single architectural style, but a working system: urban climate modelling, performance-based requirements, coordinated public-private delivery and evidence gathered after occupation.

Different cities can apply these lessons differently.

Bangkok may prioritise shaded pedestrian networks and cooler transit connections. Ho Chi Minh City may integrate heat management with flood-resilient public space. The common principle is to design for the local climate before importing sealed, energy-intensive building types.

The choice is about sequence: design out avoidable heat first, then cool what remains as efficiently as possible.

In a hotter future, the cities that succeed will not necessarily be those with the most efficient cooling, but those that need the least of it.

The writer is head of sustainability at CapitaLand Development