Budgens came up with the idea in discussion with its training provider OLS Unique Solutions.
The one-week module has been incorporated into the year-long RMT scheme after a successful trial in January. The latest such week resulted in trainee managers building extra facilities for Bonsall Primary School in Derbyshire.
Julianne Osborne, Budgens HR manager for the RMT programme, said: "We chose this module because we wanted trainees to learn outside the store and to develop strong links with the local community."
Budgens is considering rolling out the training week to regions outside Derbyshire.