New construction - Platon mat for the basement?

[stais]

Hello!

We are about to start a new construction. Two floors plus a basement (souterrain character on one side, but formally a basement). The basement will be cast thermomur. The builder plans to use platon membrane as insulation, whereas I had assumed isodrän boards or equivalent. He claims that the basement walls (thermomur) are already so well-insulated that it doesn't justify the extra cost for isodrän over platon.

Is this correct, or is it being penny-wise and pound-foolish with platon?

Thank you in advance!

 

[stais]

Of course, I've tried to read up on it myself as well. From what I understand, the thermowall is already very well insulated - and thus perhaps the point of isodrän board (compared to platon) disappears? That is, you don't gain much from the extra insulation that an isodrän board provides?

 

[skyisthelimit]

Now, there are different thicknesses of termomur as well, so it's hard to say, but generally speaking, it's quite unusual to add extra insulation on the outside of termomur... Perhaps instead increase the insulation thickness of termomur...

 

[stais]

Now there are different thicknesses of termomur as well, so it's hard to say, but generally speaking, it's quite unusual to add extra insulation outside termomur... Perhaps instead increase the insulation thickness on termomur...

Thanks for the input.

It is Jackon 350 HD