Before designing a custom kitchen island, consider the island's particular function and necessary appliances that you are going to use and store in it. Additionally, formulate a general idea about the required storage space, island height and its incorporation with the rest of the kitchen layout.
Decide what island's main function is to be. For example, some islands function as spots to eat and cook. However, priorities may differ according to personal preferences, such as using the island for food prep, cleaning or entertainment.
Figure out which appliances you may need according to the island's function. If the island is for cleaning dishes, consider the size of the sink and dishwasher. If the island is for cooking, think about the size of the stove, oven and placement of the vent. Make a list of all desired appliances for your island to prioritize and plan out their incorporation.
Take into account storage space. Judge the amount needed according to how much storage space your kitchen already has. Consider making space for items associated with the appliances, such as a drawer for cutting boards if the island is for prepping food.
Kitchen designer Thomas Ahmann generally suggests an island with a width of 3 feet, but he also asserts that a width of 2 feet may be better depending on the kitchen layout. They length may be as low as 4 feet, but it's recommended to plan for a minimum length of 7 feet to accommodate kitchen appliances.