Synopsis: Associate editor Matthew Millham explains the code requirements and practical decisions when it comes to designing a kitchen island. With detailed drawings, he describes how to best utilize the available space and determine clearances, where to set the height of the counter and placement of fixtures, and the proper dimensions of landing areas and seating heights. He also outlines the requirements for under the counter—electrical, plumbing, venting, and storage.

Oh, the kitchen island. Almost everybody seems to want one, and for good reason. With the kitchen and entertaining spaces of homes increasingly melding together, islands serve numerous purposes. They’re transitional areas, where one side may pull double duty as a homework desk and dining counter. They help define the area between the kitchen and the space beyond. They’re social gathering places that allow the cook to interact with family and guests. But ultimately, they’re part of the kitchen, and they need to play nice with it.

Before even thinking about aesthetics, it’s important to nail down the practical details. Above all, an island should add functionality and efficiency to a kitchen, not hamper them. Here are some guidelines and ideas to help you get the most out of your kitchen island and get the thumbs-up from code-enforcement officers.

Even a small island has big space requirements. The National Kitchen and Bath Association (NKBA) recommends that work aisles be at least 42 in. wide for one cook and at least 48 in. wide for two or more cooks. Walkways that pass around the island should be at least 36 in. wide. If the island has a seating area, and no traffic passes behind the seated diners, the recommended minimum space from the edge of the counter to an adjacent wall or obstruction is 32 in.…