My house is closing in on 70 years, is upgraded with good insulation and it is nothing indicating it will not last for another 70 years. My family's vacation ho

My house is closing in on 70 years, is upgraded with good insulation and it is nothing indicating it will not last for another 70 years. My family's vacation house has a core that is more than 200 years old. Both houses are made of wood. I thought it was concrete houses that had problems with transmitting sound and had poor insulation. Edit. Maybe the 40 years come from that the sidings might have to be changed after around 40 years depending on the climate. But changing the siding is not a large job, easier that changing a roof that also often have about the same lifespan