All top panels are designed to be located 1" higher than the tallest washer (including the base). End panels are 4" wider on each side of the bulkhead to hide the gap between the washing machines and the bulkhead. End panels are designed to be 1/2" from the end of the last machine. These are standard dimensions. All bulkheads are custom built so if you have a different design in mind please present it prior to placing an order.