We have a year old home in Massachusetts.
The builder only insulated the firewall between the living area of the home and the garage and the ceiling of the garage.
He did not insulate the other three exterior walls of the garage.
The garage is very warm during the summer and cold during the winter, which I think are adding to my heating and air conditioning cost.
The walls ceiling have wall board on them and are skim coat plastered.
I was wondering if it was possible to insulate the un-insulated walls without removing the existing wall board?