I follow an instagram account who are currently building a passive certified house in Ireland.    One thing that has intrigued me is that they lay the  Radon barrier on the sand blinding which is above the hardcore, then put the EPS raft on top, put in the steels and then poured the raft (seemed to do ring beam first?)   All of the others I have seen have the DPM on top of the EPS then steels and UFH. I know the design was done by tanners. Is it normal to do this? it would se