A sustainable city within a city

It’s not often that the opportunity arises to create an entire new district in a densely packed city like Hong Kong. But that’s exactly what’s happening on the shores of Kowloon Bay. Once home to Hong Kong’s iconic airport, Kai Tak is being transformed into a next-generation urban district – a vibrant destination for tourism, leisure and business that is smart, sustainable, and designed for people. 

The Kai Tak development (KTD) has been over two decades in the making, and Arup has played a pivotal role in turning this ambitious vision into reality and delivering the economic, social and environmental benefits desired by the Hong Kong government. We’ve helped to plan, design and build a district cooling system that will cut electricity bills and save nearly 100,000 tonnes of CO₂ emissions a year; road and rail links that seamlessly connect Kai Tak to the rest of the city, reducing congestion and travel time; and a groundbreaking stadium to host major sports and entertainment events, a sector that will contribute HK$1.8 billion to Hong Kong’s economy in the first half of 2025 alone.

Implementing a bold vision

Since the airport’s relocation from Kai Tak to Chek Lap Kok in 1998, the Hong Kong government has been revitalising the 320-hectare site into a model for future urban development. The KTD will accommodate 153,000 residents, with offices, public services, green infrastructure and leisure facilities all woven into a unified fabric.

Arup has been closely involved in this transformation from the outset, having played a central role in the initial feasibility study for the development of South East Kowloon in 1999, which included the KTD and adjacent neighourhoods. From strategic infrastructure and major transport links to smart city innovation and a diverse portfolio of public, private and commercial buildings that incorporate groundbreaking sustainable design, our multidisciplinary teams are delivering integrated solutions that connect the dots across the KTD. 

Together with our clients and partners, we are helping to realise the government’s vision of ‘a distinguished, vibrant, attractive and people-oriented community by the Victoria Harbour’, and setting a new benchmark for urban living. 

Mapping a smart future

Kai Tak is no ordinary major development – it’s nothing less than a smart district in the making. In 2016, Arup led a feasibility study to explore how Kowloon East, including the KTD and the surrounding industrial areas, could pioneer smart city transformation in Hong Kong. The goal? To fuel Hong Kong’s economic growth and elevate its standing as a globally competitive metropolis.

As the lead consultant, Arup developed a comprehensive smart city framework – including proof-of-concept trials, strategic implementation plans and a sustainable business model. We also provided expert guidance on establishing a centralised digital infrastructure and robust cybersecurity measures to power IoT and big data applications that will help to strengthen safety and improve accessibility across the district.

Since then, we have been working closely with the Hong Kong government, spearheading a range of smart city initiatives. Our work includes creating cutting-edge, digitally enabled planning infrastructure and tools such as a 3D digital map for Kowloon East, and laying the groundwork for a city-wide 3D mapping system – all of which are shaping the future of urban living and bringing Hong Kong’s smart city blueprint to life.

Cooling with climate in mind

Kai Tak serves as a living testbed for sustainable urban innovation. With buildings accounting for 90% of Hong Kong’s total electricity consumption and 60% of its greenhouse gas emissions, cooling is a critical challenge in the city’s sustainability journey. At the KTD, we’re tackling this head-on.

Our 20-year collaboration with the Electrical and Mechanical Services Department has delivered one of the world’s largest seawater-cooled district cooling systems (DCS), a key initiative under Hong Kong’s Climate Action Plan 2050. It will serve around 50 buildings in the KTD, realising an annual electricity saving of about 138m kWh, equivalent to a saving of HK$156m on electricity bills and a reduction of 96,500 tonnes of CO₂ emissions. 

More than just an energy-saving system, the DCS provides a vital district-level solution that supports Hong Kong’s transition to a low-carbon, climate-resilient future. 

Design that puts people first

Kai Tak is also a catalyst for economic growth, designed to attract businesses, investors and tourists. At the heart of the KTD’s new commercial hub stands AIRSIDE, a landmark mixed-use development that embodies sustainability and digital technology. Arup delivered a full suite of engineering services to create a people-first environment – one that’s inclusive, comfortable and future-proof.

The building uses Neuron, Arup’s AI-powered smart building platform, to optimise building operations, maintenance and energy use in real time. AIRSIDE is also the first private development in Hong Kong to earn all five top-tier sustainable building certifications, guided by our custom ‘CO₆ metrics’ framework which measures everything from CO₂ emissions to community value.

Similarly, the Trade and Industry Tower and Inland Revenue Centre, for which Arup provided extensive engineering consultancy services, are setting new benchmarks for energy efficiency for government buildings in the city.  The Trade and Industry Tower stands out as the first Hong Kong government office building designed to achieve both Hong Kong BEAM Plus Platinum and LEED Platinum certifications. Meanwhile, the Inland Revenue Tower introduces an innovative 'green connector’, where over 30% of the site area is adorned with lush greenery, enhancing the environmental appeal and sustainability of the structure.

World-class connectivity

Realising the vision for Kai Tak means putting the right infrastructure and transport connections in place. In 2011, Arup’s work on the ‘north apron’ area of the former airport helped to deliver roads, footpaths and utilities infrastructure, with a focus on prioritising pedestrians and minimising the impact on the environment.

More recently, Arup has led the design of some of Kai Tak’s key transport infrastructure, including stations and tunnels for the Shatin-to-Central Link and the Central Kowloon Route – critical corridors that connect Kai Tak with the wider city.

This has involved overcoming complications, some of them unexpected. When ancient relics were discovered during excavation at Sung Wong Toi station, our team redesigned it to preserve this cultural heritage, proving that progress and preservation can coexist. 

Meanwhile, our work on the Central Kowloon Route, a dual three-lane trunk road tunnelling through the densely developed urban Kowloon to link the KTD with West Kowloon, involved complex construction challenges, including a 370m underwater tunnel in the Kowloon Bay seabed, a cut-and-cover tunnel near residential areas and the historic ferry piers at Ma Tau Kok, and a complex interchange connecting busy existing highways. The Central Kowloon Route will form an essential section of Route 6, which will extend east to the Tseung Kwan O area in the south-east of the New Territories.

These projects are reducing congestion, shortening travel time and ensuring the KTD is seamlessly integrated into the city’s mobility network.

Setting new city liveability standards

When completed, the KTD will be an attractive area for residents, tourists and investors alike, thanks to its sustainable environment, connectivity and world-class amenities. Across this massive transformation, Arup has helped deliver strategy, infrastructure and buildings, combining engineering innovation and data-driven insights to bring the government’s ambitious vision for the new district to life.

From reducing carbon emissions through energy-efficient systems to enhancing urban liveability through a groundbreaking synthesis of design, data and technology, our work is helping Hong Kong raise the bar for large-scale, sustainable urban development that puts people first.