I am restoring\rebuilding a stone house in Greece and I was considering placing SIP's in the stone walls for added insulation. I live in Greece and it almost never freezes where I live but it can be pretty cold in the winter. I was wondering if anyone had tried this before or would have any reccomendations. Basically I will build two stone walls with some sort of insulation in between and I thought SIPS might work (the walls will be over half a meter thick). In general houses in Greece have little or no insulation which makes them very uncomfortable (too cold in the winter and too hot in the summer). I read a comment in another area where one person commented that they would never use SIPs in Greece, why?

The comments basically revolve around pricing, availability/shipping and labor. You pay a lot for SIPs and they are structural. So you will be defeating your purpose to a degree to pay for structural when it is not needed. If you were to use SIPs perhaps you could use a more traditional approach of a stone exterior with SIP walls and drywall. But I think the cost is going to be outrageous.

A great idea might be to use spray foam like Tiger to spray the inside wall of the outside wall of rock and then fill the cavity with fill. You can have the spray foam shipped in smaller containers then the cargo containers used for SIPs. You would create a seal to the outside and then with the fill, you would create the R value to achieve the effects of SIPs for hopefully a lot less then it would cost to import and install them.

I haven't done a straw house, and I have some fundatmental concerns about putting an organic food source in the walls, but this might be an excellent opportunity for a low cost way to insulate. Straw bails between the rock walls could probably be purchased for next to nothing and give you a great R value. The two rock walls will give you a pretty good seal.