Just recently we had a client who moved to a smaller home. They wanted a new kitchen with an island but had no room. They didn't want an extension but could not think of another way to have an island. Not thinking out of the box can be a major obstacle. We had the design challenge of a kitchen too small to accept the desired island. The client was tormented on how to enlarge the kitchen without an extension. We came up with the idea to relocate the stairs leading to the basement which were adjacent to the kitchen length. But where should we relocate the stairs, and get a further benefit? We took 3.5' wide space from one spacious room that runs along the hallway and built a new OPEN staircase with rails going alongside the room. Of course relocating the stairway we had to overcome many structural obstacles, but mission was accomplished.
Other ideas:
Bump into an adjacent room to widen the kitchen.
Consider relocating the kitchen to a larger room if possible.
Open a wall to create an open floor layout
Build for storage in another room for items used infrequently (small appliances, holiday dishes, etc.)
Turn a butlers pantry into an additional prep or cooking station