DealAnalyzer

House Hacking Deal Analyzer

Model duplexes, triplexes, and multi-room residential properties. Calculate your Net Out-of-Pocket Housing Cost, Rental Income Offsets, Cap Rate, and Monthly Cash Flow when living in one unit and renting out the rest.

How Does House Hacking Eliminate Living Expenses?

House hacking eliminates your primary living expense by using tenant rental income to subsidize or completely cover your monthly mortgage payment (PITI). Furthermore, living in the property allows you to secure low-interest owner-occupied financing with as little as 3.5% to 5% down.

1. Net Out-of-Pocket Living Cost Formula

Net Living Cost = Total Monthly PITI & OpEx − Tenant Rental Income

PITI includes loan Principal, Interest, Taxes, Insurance, and private mortgage insurance (PMI). Tenant rent directly offsets this payment obligation.

2. Monthly Wealth Compounding Formula

Monthly Wealth Delta = Rent Savings + Loan Principal Paydown

Combines the monthly cash saved compared to renting an apartment plus the equity built each month as tenants pay down your loan balance.

Step-by-Step Worked Example ($420,000 Duplex House Hack)

Here is an underwriting breakdown for a residential duplex purchased for $420,000 using an owner-occupied 3.5% down FHA loan:

1. Purchase & Down
$420,000 Price
3.5% Down ($14,700 Cash)
2. Total Monthly Debt
$2,650 / mo
P&I ($2,050) + Tax/Ins ($600)
3. Unit 2 Tenant Rent
+$1,900 / mo
Market rent collected
4. Net Living Cost
$750 / mo
Your out-of-pocket housing!
Net Monthly Living Cost ($750) vs. Standard 2-Bed Market Rent ($2,000): +$1,250 / month Saved ($15,000/yr)
Plus Year 1 Mortgage Principal Reduction: +$6,400 / yr in automatic equity paydown

Who Is House Hacking For?

First-Time Homebuyers

Dramatically reduce living costs while utilizing low 3.5% to 5% down payment options instead of waiting to save a 20% down payment.

2-4 Unit Multifamily Buyers

Analyze duplexes, triplexes, and fourplexes where tenant rental income qualifies you for a significantly larger loan amount.

Single-Family Room-by-Room Landlords

Model individual bedroom rent contributions or accessory dwelling unit (ADU) income to live 100% rent-free.

Top 5 Common Mistakes in House Hacking Underwriting

1. Failing the FHA Self-Sufficiency Test on 3-4 Unit Deals: When buying a triplex or fourplex with an FHA loan, 75% of total gross market rent must exceed the monthly PITI payment.
2. Not Underwriting Future Exit Performance as a Pure Rental: When you move out after 12 months, ensure the property produces positive cash flow with property management and vacancy factored in.
3. Ignoring Private Mortgage Insurance (PMI / MIP) Costs: Low down payment loans carry monthly mortgage insurance fees (0.55% to 1.0% annually). Forgetting PMI distorts monthly budgets by $150-$350/mo.
4. Inadequate Landlord-Tenant Boundary Setting: Living next door to your tenants requires strict written lease agreements and clear communication boundaries.
5. Overlooking Utility Meter Splitting: If an older multi-unit property has master utility meters, the landlord pays all electricity, water, and gas. Budget accordingly.

Frequently Asked Questions About House Hacking

What is house hacking in real estate?

House hacking is buying a multi-unit property or home with extra rooms, living in one unit, and renting the others to cover living expenses.

What low-down-payment loans can I use?

Owner-occupants can utilize FHA (3.5% down), VA (0% down), or Conventional owner-occupied loans (3% to 5% down).

How do you calculate net out-of-pocket housing cost?

Net Out-of-Pocket Housing Cost = Total Monthly PITI + Reserves − Total Monthly Tenant Rental Income.

What is the FHA self-sufficiency test?

For 3-4 unit properties with FHA loans, 75% of gross market rent from all units must exceed the total monthly mortgage payment.

Does DealAnalyzer store my personal finances?

No. DealAnalyzer runs 100% locally in your web browser with zero external server transmission.