We had blown-in insulation put in the outside walls of our last home. We could barely tell the difference on the warmth of the house, and the heat bill didn't change. I've heard that improvements have been made to it since then. Does anyone know if it works now?
You mean cavity wall insulation? I expect it's something that has improved over the years. I do know that the government here in the UK give grants for you to have it done so they think it works. It can't be done on my house so I don't know personally.
I think there have been improvements. I've heard that's it's just as effective, if not more so, then your typical rolled insulation. It's been around for a long time too.
I've heard that it's been improved. It's something to do with adding a glue-like material that holds it together after it's blown in, from what I recall. I'm not too fond of it, but if your walls are already covered and your outside siding is on, it's your only choice, I think.
Blown-in Insulation 
Linear Mode
