The HML i have spoken with are ok with my living in one side as long i roll it over into a normal mortgage and pay them back for the initial loan once construction is complete.

CrossCountry Mortgage How did you add value to the deal?

Cold calling building owners, mailer campaigns, text campaigns, online community groups, lender referrals, live auctions. 

But I’m interested in reputable online courses to draw knowledge from as well.

You can transform a space that you merely use for storage into a cash-flowing rental to subsidize your mortgage, your bills and other household expenses.My journey to house hackingIn Spring 2022, my neighbor mentioned he had started renting out the Accessory Dwelling Unit (ADU) on his property on AirBNB.

That leaves me to private lenders and the mortgage broker that approach the few that he knew in the Island were interested in doing a loan not a Line of Credit and Biggerpockets is not big in Puerto Rico although that's a potential market. 

You can also find appraisers through online directories.2) Ensure you have an understanding of the process.

Is it possible to actually have your roommate paying most of your mortgage in an expensive city like NYC, via house hacking?

He was referred to me by a trusted local contact and also has good reviews online. 

Conventional mortgages require higher FICO, reserves (money set aside to pay the loan), tax returns...just on that note, they typically won't count any income from the property rents until that money hits your tax returns for 2 years.