Demolition starts later this month and will be complete within six to eight months. A second stage of demolition will take place once the company has secured its new site in Whangārei, and site remediation will take place after that.
Mark Adams, Ballance's Northland project lead, said the demolition was complex. Ensuring care, alongside environmentally-sound disposal of deteriorating building materials, including asbestos, was key.
"Our Port Rd plant is an ageing and deteriorating building and is a familiar landmark to many in the Whangārei community," he said.
"Our focus is on completing the demolition safely and efficiently, while investing in new plant and equipment that will support our Northland farmers and growers."
The company has appointed Northland contractors Waldron Construction to oversee the demolition project. Ballance expects to be able to announce details about the location of its new site at Marsden Point "within a few weeks". It will lease buildings from a developer.
It hopes to secure the location of its new Whangārei site by May.
Adams would not give an exact cost of the entire project, but said it would be ''many millions''. It would create jobs during the demolition and construction phases, but would not lead to more jobs within the company.
Coresteel Buildings Northland would construct the Marsden Pt facility, which should be completed by the end of this year.
Demand for Ballance's product is seasonal, peaking in autumn and spring, and Adams said the company was managing the project carefully to ensure there was no disruption to supply, particularly over peak periods.
He said the new two-site strategy would boost customer service and accessibility, as well as product quality and reliability of supply.
Ballance will use its yet-to-be-built Whangārei site for product bagging and distribution to customers with good access to Whangārei.
The Marsden Point site will become the central distribution hub for Northland, a bulk storage and transitional facility for product coming directly from Northport, and a customer service centre.