i was gonna say - a lot of places you can put a bunch of cash down for an apartment that only exists as a picture on a sign somewhere.
I assume it's similar in most countries
What I call loan is a similar arrangement to mortgage. Buyer pledges property as collateral, pays about 20% out of pocket, rest is a debt to be paid. Defaults result in loss of ownership of property. The agreements are tripartite. Builder gets paid from the loan taken out by buyer in tranches and builder reputation matters along with market value assessment and buyer's credit profile for obtaining a loan.