Hellers is spending $18 million expanding its Canterbury site in response to growing demand for its products.

The New Zealand-owned company is doubling the size of the Kaiapoi operation on the outskirts of Christchurch and bringing it under one roof.

"It's created a real air of positivity in the industry and will have major benefits for others. The development will help stimulate the New Zealand economy and the construction industry in Christchurch," said director Todd Heller.

The expansion includes a new warehouse and distribution centre, freezers, inwards goods store, offices, ready-to-eat slicing and packing area, as well as new staff amenities.

The company spent $2 million redeveloping its Auckland factory last year, doubling the size of the warehouse and loading area.

The project is expected to be completed by April. Hellers produces 178 million sausages, 90 million slices of bacon and 100,000 Christmas hams a year.