you can use these nu-bricks they provide excellent insulation. then only thing u need on the outer side is facade, inner side pir(polyisocyanurate)-polyurethane board which is 2x effective compared to mineral wool and easy to cut to whatever size, and the inner facade. ez pz lemon sqz and super effective people complain that modern building sucks but that must just jews cutting corners because if u use good modern products they're fantastic
Finland