I have a weekend home that we heat at 52 degrees during the week, and raise to 68 from Friday night through Sunday. It takes about 12 hours to for the house to feel warm.

Is the temperature fluctuation hard on an old (1929, stone) house? Would it be better to set the temperature at 55 degrees? Is there a way to determine by what percentage the heating cost will rise, along with the temperature? We have oil heat, in a 1,400 square foot house.