I purchased an 1910 house and want to fix a few things up...ok alot of things. I'm working on the small main floor bathroom taking out the tub, outside wall as well as the wall that had the light switch and fan switch on. The outside wall is lath and plaster with next to nothing for insulation. The other wall that I took down had the light switch and fan wiring wrapped around the water lines. I know that is not right but am I wise to take down all outside walls to increase the insulation and all the inside walls to inspect the wiring? I relaize that lath and plaster is the pits but how do I increase the insulation in the walls? Glad summers here!!!