Home feeling too small?
Time for an addition! Or if you have an unfinished basement, that makes a great place to expand into. Some attics have enough head height for useable space there.
Otherwise, do what so many of your neighbors have done; add a partial second floor, or convert a garage into living space. Typically, garages are not insulated or heated, so this will require more work than at first it might seem, since the walls and roof are there!