We know they rats were living in the walls so the insulation needs to be replaced and that's probable why the electrical was problematic.

I wouldn't do anything about duct work unless there is evidence of the insulation flaking, then it should be addressed.

Jacob, we no longer vent any crawlspaces, we insulate and encapsulate which leads to much fewer issues with mold and mildew.   

.: Insulation, or lack thereof.Just ran into this one and it really surprised me, but I guess the transition from floor fan to window air conditioner to central air were all upgrades to a better way of living and that pesky outer wall insulation was an expense that just didnt make any sense back then.Energy efficiency???

All new insulation, electrical, plumbing, drywall, new water heater, pump, burner, etc. etc. etc. 

Very curious to hear some of the different perspectives on this because I am looking to try and completely insulate my businesses from one another as well as from personal liabilities. 

New electrical, plumbing, HVAC, insulation, drywall, floors, kitchens, baths, the list could go on forever!  

I insulated and they changed every bulb to LED, put plastic over windows and a bunch of other things.

Someone had installed blown in insulation from the exterior, so the plugs on the holes were popping off from getting wet. 

My inspector suggested I insulate the crawl space of the home as it is where the furnace is located; however, it is an older (but functional) unit that will eventually be moved to the attic once it dies.