I actually built my house in Isaan while I was still in Phuket. I did it remotely via video and photos. But there was no way I could have done it without a full set of architectural drawings that went down to the last nut and bolt. That way I could keep track of everything without being there. And it turned out pretty good.
yes I'm sure that's just fine. I just said you can't do anything you want on your land. I was in this business for 15 years in Phuket. And I can assure you that for example if an area is zoned for a maximum height restriction of three floors you cannot build four floors. There are very few restrictions but there are some depending on the area. Planning regulations aren't as restricted as they are in the UK but there are some restrictions, like for instance you're supposed to keep 3m between your boundary and your neighbors. But for all intents and purposes you can put any design you like on your land.
yes if it's a big company they might get the drawings done for you with their own architect and they might get them signed off for you. But it still has to be done. And no you cannot build whatever you want on your own land.
My advice would be to not do any building until you're in Thailand. But before you even think about that you need to employ a Thai architect to produce the full set of architectural drawings which have to be signed off by the local Or Bor Thor office to get a building permit. Don't build something from a rough plan. I paid a Thai architect 10,000 baht to produce my drawings. Only then did I think about construction.
immigration doesn't know if you stay in an apartment for 3 days before returning to your registered address. They haven't implanted a tracking chip inside you. 😄