Construction of Auckland International Airport's combined domestic and international terminal is under way.
Earthworks have started at its international baggage hall.
The work is one of several construction projects that mark the first phase of the airport's new combined terminal.
The 90-metre extension to the baggage hall will add about 2500 square metres.
The $8.4 million project is due to be completed by November 30.
The combined terminal could be completed as early as 2019.
The airport announced in March its 30-year vision, which includes a long-delayed second runway by 2025 and a transport corridor for passenger rail.
Auckland International Airport chief executive Adrian Littlewood said expanding the baggage hall was the first step of many towards delivering on its 30-year vision to create an "airport of the future".
A sixth baggage belt, capable of handling the luggage from a full Airbus A380 superjumbo, would be added in time for next summer's peak travel season, Littlewood said.
A seventh belt was planned in the near future to cater for passenger growth, Littlewood said.
The airport forecasts passenger numbers using the airport each year will almost treble, from 14.5 million people in 2013 to 40 million people in 2044.
The number of flights would also almost double over the next 30 years.