Need to soundproof two rooms on different levels. Live in a semi detached property. My neighbour without a party wall agreement has removed the chimney breast on two storeys and a number of bricks and just dabbed and boarded it. We have gone from being unable to hear anything to hearing light switches being turned on and clear voices.
Neighbour not interested in our concerns. Building control have been notified and have advised and investigated, stackhouse will not come down and they are not interested in sound pollution. Which system is best to dampen/reduce noise coming through? Would I need to soundproof my chimney breasts or just alcoves?