Tall buildings have long captured our imagination, from symbols of optimism to backdrops for dystopian futures. Today, they often represent corporate interests and show little regard for climate, context, or consumption. But could these structures, done right, contribute to urban liveability and sustainability?

The evolution of tall buildings traces back to the 1884 Home Insurance Company building in Chicago. Steel structural systems, passenger elevators, and mechanised climate control paved the way for ever-taller structures. The International Style of the 1930s popularised the glass-and-steel aesthetic now ubiquitous in global skylines.

Oscar Niemeyer’s National Congress building (Brasília, Brazil) features the geometric forms and clean lines common to the International Style.
Source: Arquivo Nacional

While urban density can reduce sprawl, tall buildings pose sustainability challenges. Recent studies show high-rises emit twice the carbon of low-rise alternatives over their lifetimes.

Factors include carbon-intensive materials like concrete and steel, higher operational energy demands, and potential negative impacts on urban livability.

Pioneers in the 1980s and 1990s started steering tall buildings towards environmental performance. For example, Norman Foster’s HSBC Headquarters in Hong Kong (1985) used ‘mirror scoops’ to redirect daylight and seawater-assisted cooling, slashing air-conditioning costs by 90%.

HSBC Headquarters (Hong Kong, China) by Foster Associates has the structure on the exterior, freeing up space in the core for natural light and ventilation.
Source: Paul Yeung

A current trend in tall building design is the use of timber. Engineered timber products like cross-laminated timber (CLT) and glulam now enable wooden structures to reach new heights.

Mjøstårnet (Brumunddal, Norway) by Voll Arkitekter was the world’s tallest timber building when it was completed in 2019.
© Ricardo Foto

However, debates persist about the true sustainability of timber in tall buildings, considering hybridisation with other materials and potential impacts on forests.

Two projects exemplify the future of sustainable tall buildings. The 40-storey Atlassian Central in Sydney, set to be the world’s tallest hybrid timber tower, combines mass timber, steel, and concrete in a stacked “village” concept.

It aims to halve carbon emissions over ten years through material choice, energy strategies, and design for occupant wellbeing. Each four-level “village” cluster features naturally-ventilated gardens and solar panel-fitted facades.

Atlassian Central (Sydney, Australia) by SHoP Architects and BVN will be the tallest commercial hybrid timber tower in the world upon its completion.
Courtesy of Dexus / Atlassian

The Oasia Hotel Downtown in Singapore reimagines the skyscraper as a vertical ecosystem. Its extensive green façade — one of the world’s tallest — and sky gardens provide habitat for over 18 species of animals and insects. This verdant envelope reduces cooling loads by an estimated 40%.

Oasia Hotel Downtown (Singapore), by WOHA is a haven for plants, birds, and animals, reintroducing biodiversity into the city.
© Patrick Bingham-Hall

These examples show that tall buildings can excel on multiple fronts: low carbon footprint, uplifting occupant experiences, and enhanced urban livability.

With urban populations projected to keep growing, dense cities — and tall buildings — seem inevitable. The key is ensuring these structures enhance rather than detract from urban environments.