They want you to have skin in the game.As said above, your best bet is to go to a bank and try to get the down payment.

@John Roeder,First off, if you sell the house without a down payment, the new owner/borrower has no skin in the game, so easy for them to walk.  

The extra cash you think you might be offering to the owners to convince them to let you do this is chump change compared to the risks they experience allowing someone without any skin in the game to take over management of 15 of their units for 5 months.Assuming you move forward - renting them out illegally - then the other considerations of STRs come into play, i.e. are STRs legal in this area? 

Colloquially, this is referred to as skin in the game.

The drawback would be timeframe for the build and it would not be a true no-money-down solution, given that most lenders are going to want a little skin in the game due to inherent risks with construction: however, a modest down payment on the initial land purchase is often enough equity to meet policies for the full project.Best of luck!

I understand the trend now is BRRRRs and not paying your own money but that may be the only way to get some skin in the game.

It definitely helps having some skin in the game.

However I do feel that having some skin in the game and looking at investing not as a hobby but as a legitimate future forces you to put the effort in to succeed.

The money can be based on the property and DSCR rather than the individual, but it will cost more and you'll need to put more skin in the game.

You can't visit your tenants to raise the rent on them in a bespoke suit and calf-skin wingtips.