1.) Wall lengths where you want cabinets (maximum distance cabinets can go, allowing for a 2 inch countertop overhang) (eg. countertop must stop at 120 inches, maximum cabinet length would be 118 inches).
2.) Plumbing location(s) for sink and any other water fixtures.
3.) Location of the range outlet/fixture and hood vent location.
4.) Size of window(s) including trim and locations on wall (eg. 48 inch window starting 24 inches from the corner).
5.) Size and location of all other appliances (dishwasher, trash compactors, etc).
6.) Ceiling height from floor to ceiling drywall.