HistoryFounded in 1955 by Bruce Stewart and Lance Calder is the Milton manufacturing company Calder Stewart. The pair started out building houses in Milton with their apprentice Bert Pringle. Not long after they built a joining factory to make their own window frames and cupboards for these houses. Then the took on some commercial work which expanded in farm buildings. Farm buildings led to expansion into structural steel. The structural steel branch became a separate company with a premise built at Helensburgh, Milton.
By the 1960s so much corrugated iron was being used in the construction of farm buildings that the company installed a machine at Milton to manufacturer their own. From here Calder Stewart began supplying other builders and merchants.
In the 1980s and 1990s the roofing division expanded with a factory at Invercargill.
Today, Calder Stewart is still based at Milton and employees roughly 400 people nationwide.