From my understanding the 15-18% IRR promoted by syndicators generally does not include these tax benefits either, so it is still a fair comparison.AssumptionsI had to make a few assumptions about the property and mortgage interest rate:Property value = $180,000Rent = $1680Mortgage Interest Rate = 6%I also made assumptions related to other costs such insurance, taxes, property management, maintenance, capital expenses and vacancy.

What materials do you want to use? 

Water is short-term issue, it won't be a material one.

Depending on your loan structure I'm not even sure you could legally offer a personal guarantee outside of the loan for that money without committing mortgage fraud, as anything that could hinder the ability of the primary lender to recover their principal is supposed to be declared during their diligence period, and any material changes up to the point of taking the loan are supposed to be disclosed as well.

I heard a video promoting Intellihost - wonders if anyone has used?

To avoid any confusion, this is not the same thing as ( “home sharing”, or an “owner-occupied rental.”)Improvements generally need to be depreciated over 15 years, note I said generally, depending on the nature of the improvement and how long the IRS standard depreciation period is for the cost and size of expenses.Strategies depend on a number of things including, but not limited to: type of property, your material participation, how long you plan to hold it, your goals.

Quote from @John Mason: Invasion of privacy, unclean and rude house members, maybe if they do drugs or smoke or are party animals, unwanted friends of theirs visiting at odd hours, clashes of personalityHave you ever wondered how many of the people promoting house hacks have actually house hacked themselves? 

A lot of people shrug off Modular and Manufactured but they are both cash cows and help avoid longer construction times, higher material costs and less permits. 

Some company markup their onboarding fee to like $1600 that's absurd, then they said they have a promotion and now it's $300. 

The STR Loophole (materially participate & less than 7 day rental) vs. providing substantial services.