Building cost

Have unused land, want to build units, at least 4, will rent them out instead of selling. have Thai relatives in the building game,  but need to know my cost for materials.  Besser blocks, rendered over seems to be a decent product. Anyone with any suggestions,  concrete floors,  polished or tiled? Roofing tiled or the fibre cement boards. Is steel framework available,  as wood is expensive.  Many more options I am sure, trying to keep the costs down.

Go to Thai what Su Dood which is a big store without air con and you find all construction materials there. The company is in the Central group.

Go to central web site and search for it. There's home works too that competes with home pro