You can begin by showing us some pictures of the space and a floor plan. Tell us which walls are weight bearing, and which are needed for noise control or privacy. And, how old is the house - is it a historical structure that needs to have its "bones" respected, or something more recent?

Then tell us why and where you want to change. Is a certain room too small for the way you use it? Do you find you aren't using a space, but would if it were opened into another room?