The fewer structural and mechanical changes you make, the less you'll spend. But that doesn't mean that all those changes cost a lot of money. You'll need the advice of licensed professionals to make final decisions, but you can at least get a rough idea of how much extra major changes would cost by answering the following questions:

• Is the wall you want to move a load-bearing wall? Load-bearing walls support the structure of the house, and moving them is a complex job for a professional. Typically, an interior load-bearing wall runs the length of the house, at about the center of the structure.
  
• What rooms are directly above and below the kitchen? If the rooms above and below are finished, it'll be a lot more difficult to reroute plumbing pipes, heating ducts and electrical wires.
  
• Does your new design require that you move existing doors and/or windows? If so, this makes the job more difficult, because exterior walls are always load-bearing.