The Changi Airport Group has awarded two contracts worth S$4.8 billion ($3.7 billion) for the construction of its biggest passenger terminal as Singapore seeks to tap into the travel boom.

Dubbed Terminal 5, it will have an annual passenger capacity of 50 million when completed, according to a company statement. Changi Airport is among the world’s busiest aviation hubs, handling almost 68 million passengers last year.

A joint venture between China Communications Construction Co. and the Singapore unit Japan’s Obayashi Corp. was awarded the S$3.8 billion substructure contract while the S$950 million contract for airside infrastructure works was bagged by local contractor Hwa Seng Builder.

“The appointments of the contractors for substructure construction and airfield works bring us closer to the start of T5’s construction,” Ong Chee Chiau, managing director of Changi Airport’s Changi East said in the statement. T5’s construction will start in the first half of 2025, and is expected to be completed in the mid-2030s, he said.

T5 represents one of the most complex construction projects in Singapore, according to Ong. It is part of the larger Changi East development that includes Changi Airport’s third runway, cargo logistics facilities and other supporting aviation and ground transport infrastructure.

The substructure contract comprises the construction of the foundation and basements of the T5 main passenger terminal and ground transportation center, including a portion of the tunnels that would link it to the existing Terminal 2, the statement said. The substructure covers 140 hectares with a basement depth of up to 28 metres, equivalent to about 5,200 Olympic-sized swimming pools put together.

The airside infrastructure works covers the development of remote aircraft stands, connecting taxi lanes and ancillary support buildings, according to the statement.

“Together with our partners, we will ensure that the high standards which define Changi Airport can be replicated or even surpassed in the development works of T5,” Ong said.

Changi Airport was named last month as the world’s best airport at London-based aviation consultancy Skytrax’s World Airport Awards, reclaiming the title from Qatar’s Hamad International Airport, which took the coveted accolade in 2024.