In old house renovations, which should be planned first: HVAC or plumbing and electrical?

Once an old house is opened up, HVAC, plumbing, and electrical often compete for the same space. If you don't plan out where the ducts go, whether the panel is sufficient, and if the drainage slope is adequate beforehand, you'll be making constant changes right up until the drywall goes up. I usually determine the locations of the major items and main lines first before discussing the details…