Hi all,
I used to post on here many years ago, got some great advice and nice to see a few familiar names still here.

Since I last did any renovation wood fibre has become affordable, so I would be interested to use it, and/or some kind of wool to add insulation to my current house: old, barn type Scottish rubble wall type construction, which has a suspended wooden floor and lath and plaster walls with a gap between the wall and the back of the dry lining.

What is a recommended recipe in this case for walls? I imagine new stud walls with insulation between / on top of the studs, but not sure where any membranes or barriers should go, and can the rigid board be plastered or is plasterboard on top still advised?

Likewise for the floor, to which I would also like to add UFH.

Only current insulation is in the loft, 150mm rock wool.

Any suggestions or examples appreciated!

Thanks
Evan