I am looking at having sound insulation on the party wall in my semi detached house. However, I am unsure what type is likely to have the best results without having to build a new wall. I have seen references to foam insulation and also acoustic insulation boards which can be fixed to the existing wall. What is the best type of insulation for me to go for? Also how much should I be looking to pay for insulating four rooms that have a shared wall with the adjacent house?
