[ryanianian]

> All the banks care about is if the cost of the new mortgage is going to exceed your debt to income ratio.

Not exactly. The underwriting process is very different for full-time residences versus investment/rental properties. Rates are usually higher, debt/income ratio must be lower, and appraisals and cashflow analyses include rental market considerations.

Given this it's entirely reasonable to assume the rift between mortgage products for investment vs residence to widen. If congresspeople want to do something about perceived imbalance between residence and income real-estate, they could change federal subsidies or underwriting requirements for income properties making mortgages for income properties much more expensive and/or harder to get.

(Just realized a peer comment said something similar.)

[Kon-Peki]

That's not what the article is saying. You buy a house as your full-time residence, live in it for a few years, and then buy another as your full-time residence. The previous one is rented out. As long as you wait a few years, the bank holding the loan on the previous house doesn't care. That original, owner-occupied rate is locked in for the life of the loan.