@Rick19744 , temporary regulations are termed temporary for the sake of it. My understanding is that they are there from early 90s if not late 80s.
Typically, your investment properties are smaller investments compared to how much you have committed to your primary home. Thus, your downpayment in primary home is significant compared to what you have put as downpayment for investment properties. Add. to it the fact that rental property generates taxable income, a reasonable person would want pay off his primary home faster than his rental.
Granted that if these are two separate loans, you need o pay bare minimum to both every month anyway. But that's where the way IRS looks at the loan comes into picture. IRS doesn't care what your lender is advertising the loan to be. IRS just cares how you are using that loan. Say, you do HELOC on primary and use it for renovating the primary (and say you are still below 750K after HELOC), you can deduct the interest in itemized deduction as mortgage interest. If I you use the same money to buy car, you can't deduct the interest. You use the money for downpayment of rental property, you can deduct interest on HELOC portion from your rental income from the property.
