According to the (more sciencey) haunt investigation shows, most haunty effects are from old plumbing, inappropriately shielded magnetic fields, air pressure, and so on.

So if you fix all the problems in the process of replacing the house, such as modernizing the electrical wiring, then yeah, the venue will become less haunted.

If, however, you fail to remove the bodies, proverbially or otherwise, you’ll just piss off the ghosts.