The Covid-19 crisis had also played a part in more recent delays, with impacts on supply and shipping.
Bertram, who has accepted a job from whence he came, at Scots College, Wellington, as director of boarding, said the school, which has a roll of 1150-1200, had coped through what will have been more than three years of major redevelopment headed by lead contractors Stead Construction, of Hastings.
A landmark event was the opening of six science rooms in February, and a feature of the construction is the absence of corridors, which he says is a factor which was possible in Hawke's Bay because of the climate, but an unlikely design in other parts of New Zealand.
The school is also planning a separate library refurbishment costing over $1 million which it is hoped may also be completed in time for the school's celebration in June 2022.
Bertram revealed his departure plans to the board at the start of the year and will leave the school at the end of Term 2.
Landon said the job has been advertised, strong interest has been shown and it is hoped an appointment will be made by mid-June.