Another one that depends on the loan you get. Smart money is to put down just enough to get out of the PMI (more money being pissed away on nothing), I've had that as low as 10% down and as high as 20% down. Another thing to ask after is if you can manage your own insurance/taxes (otherwise the bike will take excess money from you to hold for those payments, you get the money back but I'm a fucking responsible adult and can do this myself). As for buying vs building, I'm starting a building right now (shop) and it's Absolutely cheaper to buy something that's already built. By a long ways. You're also going to run into limitations with city/county codes (minimum size so they can tax the shit out of you... min for my county is TWICE what I live comfortably in now), nevermind the headache of actually building. There are all sorts of supply-chain issues, huge demand (and low supply of builders), it's just a bad time to be building anything. If you can manage, buy what you need... if building seems to be the only option, try Alternative routes (barndomium type thing), if it's a Really rural/secluded place it's possible you could just put up a "shop" building and build out a residence inside that's off the record.... just understand you won't have any kind of insurance protection.