The barrier is the additional complexity - now you are operating two sets of books, and filing two tax returns, and have more operating agreements, more state registrations, etc, need to manage cash better, need to keep in constant mind that your rents need to be a supportable FMV, which may require getting third party certification on your rents so that in the event of an IRS audit, what you have done is supported.In short...the size of the project, and the taxable income, need to be of enough scope to make all the additional costs and annoyances worth it. 

It depends on how much the NY house will sell for vs how much the TN house will cost.

Also, what are your opinions on telling the potential tenants you are the owner in the other unit?

So how much did this cost me to get involved besides an awful lot of time?

@Rania MutumheHouse hacking means turning a place into a rental space, which calls for fix-ups, planning costs, and expert help.

I am looking for an investor to partially fund some of the soft costs for a large townhouse project I'm working on. 

I figure a one time expense to prevent major water bills in the future might be in my best interest as long as it doesn't cost too much. 

They can’t lend you more because if they have to foreclose it will cost them at least 10%.)Then you want to take that $300k and get a loan for another $300k with that $300k to buy your dream home.

My partner will be general contracting at no cost, although he will be paying a few key 1099’s and contractors .

In this same deal, the investor would need to come with 15% plus closing costs and let's call it 17k.