Profit after tax was 41.6 per cent above budget due to interest cost savings accrued because of the delay of the terminal redevelopment project.
The total expenditure for the half-year was 36.7 per cent ahead of the same period last year, resulting from the increased cost of the airport's rescue fire service due to the service requirements required by the company and the Civil Aviation Authority, he said.
In December last year, HBAL confirmed Arrow International would be the main contractor to redevelop the terminal building and work was due to begin this month to be completed in November next year.
"Following consultation with both the airport's tenants and the main contractor a revised staging plan has been developed - the objectives being to minimise the operational disruption, preserve customer experience and offer savings to the project," Mr Porter said.
The project will see check-in areas installed at the southern end of the terminal and a new automated baggage handling system at the opposite end.
There will also be a dedicated arrivals gate instead of the current departures and arrivals from the same gate.
New facilities will include a cafe, and offices for Air New Zealand, Jetstar and Sounds Air airlines.
In the meantime a new airport link road connected to State Highway 2 is scheduled to be finished in August this year.
HBAL is designing additional works to integrate the link road to the existing internal roads at the airport, construction scheduled to start in the second half of this year.
Looking ahead, Mr Porter said that while passenger growth had been growing beyond the long-term average, this was expected to slow in the full 2019 and 2020 years.