In this specific case the unit is not built in such a way that I could sub-divide it into separate spaces (there are also zoning restrictions for density, etc.).

There are certain rules the IRS has for holding real estate in your IRA. 

I currently live in a 4 unit in a different city that I have been house hacking for 3 years and i'd like to change my residence to this new property.I'd appreciate some guidance on what steps I need to take as far as making sure I am in compliance with the HUD rules.

Good info @Jerry Jenkins The property is in Missouri, so I assume your rule of thumb applies there as well?

Good morning,I was wondering if anyone knows of any specific rules in Philly for rentals.

Property/Deal Profile General Guidelines Purchase Price 700,000 1 Percent Rule (%) 0.857142857 Down Payment (%) 3.50% 50 Percent Rule 3000 Down Payment ($) 24500 Cap Rate 8.214857143 Interest 4% Cash-on-Cash Return 26.73744578 Term (years) 30 Loan amount 687,321 Income Cash Flow Rental Income 1 2500 Total Monthly Income 6000 Rental Income 2 3500 Total Monthly Expenses 5075.33 Laundry Income Storage Income Misc Income Total Monthly Cash Flow 924.67 Total Monthly Income 6,000 Total Annual Cash Flow 11096.04 Expenses Cash-on-Cash Return Taxes 750 Down Payment 24500 Insurance 58 Closing Costs 0 Water/Sewer Rehab Budget 30000 Garbage Misc Other -13000 Electric Gas Total Investment 41500 HOA Fees Lawn/Snow Vacancy 200 Repairs 200 CapEx Property Mgmt.

Each state's tax jurisdiction has its own eviction rules.

I broke some of my own personal/professional rules, that is one of the reason that I'm in this predicament.

There is a tax rule called de minimis, stating any improvement under a certain threshold can be taken off as a repair instead.

If you truly want conservative estimates stick to the 50% rule.