1). Mortgage Assistance: One of the most significant advantages of living in one unit of your 4-plex and renting out the other three is the potential for rental income to cover a substantial portion, if not all, of your mortgage payments. This means you could live rent-free, or close to it, while your tenants effectively help you build equity.
2). Tax Advantages: Owning a 4-plex can offer you various tax deductions, including mortgage interest, property taxes, and maintenance costs. Additionally, because it's an investment property, you might be able to depreciate the building's value, further reducing your taxable income.