Also, does it get blown in at every level or can you just drill holes in the part wall of the attic and start filling? I just had the house plastered so don't really wanted start ruining nice fresh walls.
I think they do it from outside, no? Or did you have the outside of your house plastered too?
Presumably your neighbours heat their houses? I would imagine most of the heat loss is to the outside world. Does the dividing internal wall even have a cavity?
I think they do it from outside, no? Or did you have the outside of your house plastered too?