In my previous house, I had two inside upgrade projects; the bathroom and the kitchen. The house was c. 1929 and the original load center was a 60 amp pull block with 20 amp fused circuits (originally; when I checked the wire sizes, some of them went down to 15 amp). The first project was replacing the load center and a separate subpanel for the electric water heater with a 150 amp 42 count breaker panel. I didn't go to 200 amp on the EC's recommendation because the overhead would have to have been replaced. The only thing the EC and I did (yep, he let me play helper) was move over the existing circuits and replace a portion of one of them that was still K&T. The bathroom job was first and went OK, if a little longer than we had planned. When we got to the kitchen, I had separate circuits run for the range hood, microwave, and refrigerator. This was all discussed with the GC ahead of time. Here's the reason: after the panel upgrade, it was still the case that when the refrigerator kicked on, lights all over the house would dim. I worried a lot about A/C loads in the summer not playing well with the refrigerator. Rather than trying to dissect the circuit topography, I just split up the loads directly onto 15 amp circuits. After that, I could run the electric oven, microwave, washer, dishwasher, and three 8,000 BTU/hr window units in August heat and see nary a flicker when the refrigerator compressor kicked on. If I ever have a similar chance, I'll do it again.