Blue Diamond will take over the new £5m, 6,000sq m centre and intends to continue trading throughout the work on site.
Managing director Alan Roper said: "Groundwork is due to start this spring on the new development, which will take three years to complete as we intend to remain open throughout. The project involves knocking down the original building and building a new centre that is double the size."
He added: "Redfields has proved to be an easy opportunity as the business has responded well to a broadened and enhanced product offer. We have particularly focused on the planteria, where sales are up 50 per cent in the year to date." The centre's average spend is up 10 per cent.
Roper said the increase was particularly pleasing because the centre used to belong to Choice Marketing and benefited from its pamphlet drops, which no longer happen.
Groundwork is being carried out by a local company but the building contract has yet to be assigned.