There are Many Types of insulation on the market today:
Before you decide on the insulation for your home make sure you have the correct information.
All products should be certified with Irish Agreement certificate or equivalent
All products have data sheets ask the supplier for them.
All products Will have a lambda value and this is the value that is used to calculate you U value.
U values are calculated on the total makeup of the wall/roof from the paint in the inside to the plaster/tile on the outside.
Get your Building Energy Rater to check the calculations.