I am in the US. Our local residential building codes only require you to update things if you open the walls for any reason. So, for those rooms that I have remodeled, I had to add insulation, fire-blocking (house is balloon construction), and update the electrical. Basically, if I opened the wall up, I had to update everything in that wall to meet modern codes. If I don't touch it, I don't have to do anything. At this point, I have three rooms left that I plan to remodel, the master bedroom is one of them. The bigger surprise for me was the framing. I fully expected to have to improve the framing, but the inspector said that it was well done. He even commented that the builder must have gotten a really good deal on nails and didn't skimp on those. :)