I have – but in another state. (Pennsylvania)
These are the issues I dealt with:
– furnace was older than I was. Solution: got a maintenance contract on it (oil furnace) and when things broke, they fixed it. When I sold 7 years later – it was still running, but with replaced blower, and burner.
– no insulation to speak of. I got quotes and it was on my to-do list. It was cheaper than it otherwise would have been because the turn of the century twin had balloon framing. But still not something I could just write a check for. Solution: save towards insulating it, and wear sweaters.
– inadequate electrical, including some old knob and tube. Solution – replace about 80% of the electrical and put in a new panel. Blow off entirely the electrician who gave me a quote about 3 times more than the others because I was a woman. (Seriously – this guy noticed my tools out and said they were “cute”.)
I have friends who own older bungalows in University Heights and in Kensington. They’ve upgraded the wiring. One had a really cool reflective coating put on their flat roof – which dropped the summer temps considerably. Both have tried to keep with the charm of the older houses – keeping the old tile in the bathroom, etc.