At least in the US, having a certain number of presales is literally a requirement to get loans for developers. My folks bought their last two houses like this

At least in the US, having a certain number of presales is literally a requirement to get loans for developers. My folks bought their last two houses like this. I bought my last two condos this way. All before ground was broken, average wait time of about 2 years. Note that in these cases a presale does not mean the property is fully paid for - it means that some deposit and paperwork have been filed and that the final price on close of escrow has been locked in.