The other possible area of extension is to extend their coverage of the home improvement market by offering greater home improvement services. This could range from maintenance (e.g. plumbing), through small home improvement (e.g. painting/decorating, odd jobs), to building extensions.
The advantage for the DIY/hardware store is increased (and diversified) revenue, and promotion of their brand outside the DIY community. Additionally, as the DIY/hardware store already buys materials and tools in bulk, the cost discounts are already in place. The benefit to the consumer is a one-stop-shop for home improvement, and the reliability/quality-control that would necessarily come from a high-brand-value DIY/hardware store.