Auckland International Airport says an expansion of its international facilities will cost as much as $180 million.
The project sticks with the core of the original 1977 international terminal building but expands it in stages.
The airport handles about 16 million passengers annually but expects that to rise to 40 million by 2040.
By December 2016, there'll be a reconfigured farewell area, new expanded security screening and processing area, and a new home for an anchor duty-free shop.
By May 2017, space for another duty-free shop and the first half of a new passenger lounge and retail hub will be ready. The final phase will be completed by early 2018.
The project's building contract has been given to Fletcher Construction.
"This project is one of a series of significant infrastructure and facility upgrades under way at Auckland Airport to ensure we are keeping pace with growth and delivering on our 30-year vision," Auckland International Airport chief executive Adrian Littlewood said.
On January 29, 2016 the airport will celebrate 50 years of operations.
The airport told shareholders at its annual meeting last year that it expects capital spending of between $230 million and $260M in the 2016 financial year, ahead of an earlier forecast of between $190M to $205M.
Auckland airport also said it expects to have one of its busiest summers ever this year.