Three ingenious ways architects are designing buildings to stay cool in a heatwave without air conditioning

As the UK braces for yet another record-breaking heatwave, we are starkly reminded of the need for climate-resilient architecture in a warming world.

In the last few decades, architects have been addressing this by considering passive design strategies. These are design approaches that harness natural resources, such as sunlight or wind, to achieve indoor comfort, without relying on energy-hungry options like air conditioning.

Architects around the world are developing designs that not only respond to their local climates and cultural contexts but also push the boundaries of sustainable design. Some are inspired by vernacular architecture, a type of traditional construction specific to the building’s location and the locally available materials. Others learn from nature and employ biomimicry, a process that copies strategies found in natural ecosystems to solve human design challenges, as these three examples illustrate.

1. Ventilation inspired by termite mounds

The Startup Lions campus is an information and communications technology campus located on the banks of Lake Turkana, Kenya.

This building is inspired by African termite mounds that are found around the site. The mounds have a network of tunnels and vents that allow cool air to enter through small openings at the base, while warm air rises and exits through a central chimney, maintaining a stable internal environment.

Similar to the mounds, the building has specially designed, adjustable low-level openings that carry fresh air inside. As the air warms inside the building, it rises due to its lower density compared to the cooler outside air.

The towers then help extract this warm air through the stack effect, whereby the difference in air pressure and temperature causes the warm air to rise and escape through the top of the structure, drawing in cooler air from below. This process helps to continuously circulate fresh air and cool the building.

2. The power of double roofs

In Burkina Faso, an extension at Gando primary school stays cool in extreme heat through natural ventilation enabled by its double roof.

The double roof serves two functions. First, it provides an overhang, shading the whole building against the harsh sun throughout the year. Second, as the heat naturally rises, it escapes into the gap created between the first and second roofs. Prevailing winds then quickly carry it away, accelerating the process and cooling the building more efficiently.

The inner roof, which is vaulted and composed of perforated ceiling slabs, lets heat escape more effectively. The rising hot air can be rapidly carried away by the wind, further enhancing the cooling process.

To complement this, the outer roof is designed with a curved shape, creating what is known as the Venturi effect – a phenomenon where air accelerates as it flows through the narrower sections formed by the curve. This significantly boosts the building’s natural ventilation and shows how multiple strategies can build on each other to achieve a greater cooling performance.

3. Embracing Earth’s natural insulation

The architectural solutions employed in the Startup Lions campus and Gando primary school extension are tailored to warm climates, but the underlying principles of working with local climate and environment are universally applicable.

In the UK, where the climate is generally milder, earth sheltering has proven to be impactful in maintaining comfortable indoor temperatures. Underhill, for example, is a house designed by British architect Arthur Quarmby in west Yorkshire that uses the stable temperature of the Earth to stay cool in summer.

Earth is a powerful insulator. While the temperature of the air is subjected to sunlight, wind and general weather patterns, underground temperatures stay relatively constant at a depth of 2-4m. This is because the ground has a much higher thermal mass than air, meaning it can absorb and store large amounts of heat without significant temperature changes.

As a result, earth sheltering protects and buffers the building from outdoor temperature extremes, precipitation, wind and humidity. This, in turn, keeps indoor temperatures more stable, preventing overheating during the summer and maintaining a warmer environment during the winter.

As we face increasingly frequent and intense heatwaves, the need for innovative architectural solutions becomes more pressing. Buildings can remain comfortable without resorting to energy-intensive mechanical systems. The construction industry has a duty to prioritise climate-responsive designs that minimise energy use and contribute to creating a more sustainable and resilient built environment.

Sara Saadouni does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.