The average 30-year fixed mortgage rate hit 7.28% last week, up from 6.34% a year earlier [1]. If you’ve been eyeing a duplex, you’ve probably already heard the verdict: house hacking is dead, the numbers don’t cash flow anymore.
That verdict is answering the wrong question. A house hack was never supposed to be a rental property that happens to have you living in it. It’s a housing decision with an investment attached. The right test is simple: after the tenant’s rent and the principal you pay down, does living in the duplex cost you less than renting?
Here’s that test, run with real arithmetic at today’s rate.
The setup
Every number below is illustrative. Swap in your own market’s prices and rents; the structure of the math is what matters.
The duplex: $450,000, two identical two-bedroom units. You live in one and rent the other for $1,800 a month.
The alternative home: a $360,000 single-family house in the same area.
The alternative to buying: renting a two-bedroom like the one you’d live in, for the same $1,800 a month your tenant would pay you.
Shared assumptions for both purchases:
- 20% down and a 30-year fixed loan at 7.28%, matching the borrower profile Freddie Mac’s weekly rate survey assumes [1][2]
- Property tax of 1.1% of the price per year
- Insurance of $200 a month on the duplex, $150 on the house
- A maintenance reserve of $300 a month on the duplex, $250 on the house
- A 5% vacancy reserve on rent you collect
- Your down payment would otherwise earn 5% a year invested
That last line matters. Renters keep their down payment invested. Owners give that up, and an honest comparison has to charge for it.
The three lines
| Monthly, year one | Rent | Single-family | House hack |
|---|---|---|---|
| Mortgage (principal + interest) | none | $1,971 | $2,463 |
| Property tax, insurance, maintenance | none | $730 | $913 |
| Rent you pay | $1,800 | none | none |
| Rent you collect, minus vacancy | none | none | −$1,710 |
| Cash out of pocket | $1,800 | $2,701 | $1,666 |
| Principal paid down (it’s still yours) | none | −$231 | −$289 |
| Lost earnings on your down payment | none | +$300 | +$375 |
| True monthly cost | $1,800 | $2,770 | $1,752 |
Read the bottom row.
Buying the single-family house costs you about $970 a month more than renting. At 7.28%, that’s the honest price of owning a starter home in this example, even after crediting you for the principal you build.
The house hack costs you about $48 a month less than renting. Not a windfall. Not “live for free.” But roughly break-even with renting, while you own a $450,000 asset and a tenant pays down your loan.
That’s the real story at 7%. House hacking didn’t stop working. It stopped being a home run and became a slightly-better-than-renting move that beats buying a single-family home by roughly $1,000 a month.
What the rate rise actually cost you
At last year’s 6.34% average [1], the same $360,000 duplex loan would cost about $2,238 a month in principal and interest. At 7.28% it’s $2,463.
That’s $225 a month. Real money, but notice it didn’t flip the answer. The house hack still lands right around the cost of renting. What the higher rate killed was the version where the tenant covers everything and you live free. That version was always the exception, not the rule.
The move-out test
Here’s the part most house-hack pitches skip. Eventually you move out, and the duplex has to stand on its own as a rental.
Rent both units at $1,800, keep the 5% vacancy reserve, and add 8% for a property manager now that you’re not living on site:
- Rent collected: $3,600
- Vacancy reserve: −$180
- Property management: −$288
- Mortgage, tax, insurance, maintenance: −$3,376
- Monthly cash flow: −$244
- Add back principal paid down: +$289
- Monthly result including equity: about +$45
At today’s rate, this duplex bleeds a little cash every month as a pure rental. It roughly breaks even only when you count the principal your tenants are paying down.
That’s the honest picture for your plan. If rents rise over the years you live there, that gap closes. If they don’t, you’re holding a property that asks you for $244 a month to keep growing your equity. Decide now whether you’d be comfortable with that, because “we’ll figure it out when we move” is how house hackers end up as reluctant landlords.
What the table doesn’t count
Three things are left out on purpose, and each one could move your answer.
Appreciation. If the duplex gains value, that’s a gain the renter doesn’t get. It’s also not guaranteed, so we don’t bank on it in the base math.
Taxes. Once you rent half the property, the IRS treats the rental half separately. You divide expenses between personal and rental use, report rental income and expenses on Schedule E, and depreciate the rental portion of the building over 27.5 years [3]. That depreciation can shelter some of the rent from tax. Run your specific numbers with a tax professional before counting on it.
Your time. You’re a landlord. Late-night repairs, tenant turnover, and the person on the other side of your wall are real costs. The table prices none of them.
The test, for your market
You don’t need a spreadsheet. You need six numbers:
- Your all-in monthly owning cost (mortgage, tax, insurance, maintenance)
- The rent you’d collect on the other unit, minus about 5% for vacancy
- Your first-year monthly principal paydown (any amortization calculator will show it)
- Your down payment × 5% ÷ 12 (the earnings you give up)
- What you’d pay to rent a comparable place
- Your move-out cash flow, with management fees included
Line 1 − line 2 − line 3 + line 4 is your true monthly cost. Compare it to line 5. If it’s lower, the house hack beats renting. If it’s lower than the single-family alternative too, it beats buying. Then check line 6 to make sure you can live with the property once you’ve moved out.
The rent on the other unit is the most sensitive number. In this example, every $100 a month more (or less) in rent moves your true monthly cost by $95 in the other direction. Get real comparable rents, not the listing agent’s estimate.
A note for growing families. If you have a baby on the way, weigh the lifestyle cost honestly. A shared wall, a tenant who works nights, and a landlord to-do list hit differently with a newborn. If the true monthly cost only beats renting by $50, that margin may not be worth it. If it beats renting by $400 in your market, it very well may be.
The bottom line
At 7.28%, house hacking isn’t the free-housing shortcut it was sold as. In this example it’s roughly a wash with renting and about $1,000 a month cheaper than buying a starter home, with a tenant building your equity and a real obligation waiting when you move out.
Your one move: run the six-number test with real listings and real rents in your area before you look at a single duplex. The math will tell you whether this is a smart move for you or just a tough one.
If you want the math behind the next big money headline, the Thousandaire newsletter breaks down decisions like this one, with the numbers.
Last reviewed: October 6, 2026
Sources
- Freddie Mac, “Mortgage Rates Average 7.28%,” Primary Mortgage Market Survey news release, October 1, 2026. 30-year fixed-rate mortgage averaged 7.28% as of October 1, 2026; 6.34% a year earlier. https://freddiemac.gcs-web.com/news-releases/news-release-details/mortgage-rates-average-728
- Freddie Mac, Primary Mortgage Market Survey (weekly averages and methodology). Survey covers conventional, conforming, fully amortizing purchase loans for borrowers with 20% down and excellent credit. https://www.freddiemac.com/pmms
- Internal Revenue Service, “Know the tax facts about renting out residential property” (FS-2018-14). Dividing expenses between rental and personal use; Schedule E reporting; 27.5-year recovery period for residential rental property. https://www.irs.gov/node/60226
The Thousandaire Editorial Team creates practical, evidence-based personal finance content for people building real wealth. We break down investing, retirement, taxes, real estate, and other wealth-building decisions with clear explanations, real numbers, and no hype
