>>212050730
That's not too different from holiday homes you can buy here (mainly marketed at old people). They are basically caravans (so they aren't considered real houses and can avoid being taxed like one), but they build decking around them so that boomers can sit outside on a nice day. Even if these look alright in isolation, the issue is that they tend to pack too many of them together that it becomes cramped. And if you own enough land to ensure you have plenty of space around you, you might as well build a proper house.