Before anything else, figure out what you want your island to do. Will it be a prep station, a dining spot, extra storage, or perhaps house an appliance like a sink or stovetop? Knowing its primary role helps determine the size, features, and necessary utilities. If you want seating, you'll need an overhang. If it's a cooking zone, you'll need power and possibly ventilation.
This is crucial! You need enough clearance around the island – ideally 36-48 inches – for comfortable movement and appliance access. A good rule of thumb is to measure your kitchen and even mark out the proposed island footprint with painter's tape to visualize the space. Ensure it doesn't disrupt your