As well as a nook (a girl's shed) I have somewhere to store my food. We created a room that passively cools. There is a hole in the floor that is piped to the south. The ceiling has a hole and a whirly bird to draw that cooler south air up into the room.
Hubs got some shelves and voila!
Storing food has meant huge savings for us. I buy on sale or just in bulk, buy the tray etc, especially from Aldi. This reduces the numbers of trips to the shops. No spontaneous spending, if fire or flood cut us off from town we have stores, we eat at yesterdays prices and a surprising benefit, less illness. Keeping out of the shops has reduced our exposure to lurgies so we reduced doctors visits and medication.
This coupled with a productive garden means we are set for months!