4. How high should the counter be?First things first: Determine your seating height. If you want to have bar stools at your island, you'll need to decide if it's 36 or 42 inches high. A 42-inch-high bar stool and bar tend to have a bit more flexibility — the island can be designed in two levels, with the working side set lower for prep work and the dining side higher to accommodate bar stools. The step in between is a handy place for electrical outlets, too.A 36-inch-high bar provides for seating that's between a typical bar stool and a table seat. It doesn't allow for quite as much flexibility in design but can be a good choice for a defined eating area. Ahmann suggests leaving at least 12 inches of overhang for seating areas, but 15 to 18 inches tends to feel more comfortable.