As for the materials used it's mostly stuff I had laying around. I did buy 10 2x4's (5.1meters) from store tho, and some bags of concrete + the metal to hold the studs (sorry idk the proper name for them, English is my 2nd language). Also I got the drenation mass delivered (crushed rock 0-32mm). The cost of that is really the transportation (and that's been doubled in the last few years). Metal plates (used on roof and 2 walls) are from my old bathroom roof before it was renovated. Also screws and nails + insulation i did buy, xps for the corners and Styrofoam for the rest (all 5cm).