China is spending $11bn (72bn yuan) on a second airport in the southwestern city of Chengdu to meet growing passenger demand. Designed with the help of French architects, it will be the biggest in western China and the fourth biggest in the entire country.

Located near Jianyang city about 50km southwest of Chengdu city centre, the new Tianfu International Airport will have three runways in the first phase scheduled for opening in 2020.

By 2025 it will be catering to 40 million passengers a year, reports China Daily.

Eventually it will have six runways and the capacity to handle 90 million passengers a year – roughly equivalent to London’s Heathrow – but it was not disclosed when.

Approval for the new airport came from China’s main economic planning body, the National Development and Reform Commission (NRDC), last week.

The runways will be longer than normal to accommodate larger aircraft. One will be at least 4km, according to the NRDC.

Once the airport is built, Chengdu, the provincial capital of Sichuan province, will become the third Chinese city to have two airports, after Beijing and Shanghai.

Pan Gangjun, the general manager of Sichuan Airports Group, told China Daily that the airport is likely to be the fourth largest in China in its first phase.

The winning design was by China Southwest Architectural Design, China Airport Construction Group and French architect Aéroports de Paris. It will have two symmetrical terminals in the shape of the Sunbird, a mythical animal that is the symbol of Chengdu. The passenger gates are located on six arms that radiate from the terminals.

The plan was approved last year and comes under the country’s 13th five-year economic program, which aims to build at least 50 airports by 2020.

The Sichuan Provincial government is planning to make Tianfu the centrepiece of an “aerotropolis”.

It has described the airport as a global transport hub and “the air bridgehead” for the Yangtze River Economic Zone, as well as the “largest aviation port of the Silk Road Economic Belt”.

China’s provision of airports per capita is currently much lower than the US or Europe, but rising incomes and the proliferation of domestic budget carriers is expected to lead to a rapid increase in demand. At present North America has 2.5 airports per million people, Europe has 1 and China has 0.13.

Photograph: The design of the airport is based on the Chengdu “Sunbird” (ADP)