Has the gas line size and pressure been confirmed? Natural gas should be 7” water column. Bulk propane should be regulated to an 11” water column. Has the plumber or gas technician planned for the total BTU volume of all the BBQ equipment? If additional gas appliances are running off the same line such as fire pits, pool heaters, and patio heaters, a load test may be required.
Will the kitchen be plumbed for water supply? Hot and cold or just cold? An under-counter water heater installed below the sink is usually less expensive than running hot water lines and performs better. Have you provided a shutoff valve and a drain to winterize the water lines? Do you plan to get rid of the waste water with a french drain or attach it to the city’s sewage?
Have electrical outlets been planned throughout the kitchen and above the counter? Be sure to provide a dedicated circuit to any refrigeration as these typically need more amperage. Outlets for standard appliance should also be on a separate circuit. Outlets above the counter can be used for blenders, rotisserie motors and the like but you will also need outlets below the counter for the outdoor refrigerator, BBQ lights, BBQ ignition, water heaters and things such as these.