I am purchasing a townhouse and asked the builder if I could pay for extra insulation or soundproofing between my townhouse and the one next door. The answer was no. The specs say that the wall will have R-13 kraft faced fiberglass batts. The drywall will be 1/2" thick, field screwed and permieter nailed to framing.

Any advice? Is this sufficient? If not and the builder will not allow additional insulation, etc., what can I do.

Thanks,