Most first short-term rental down payments come from equity in a primary residence, and the choice between a HELOC and a cash-out refinance turns almost entirely on one number: how far below current market your existing mortgage rate sits.
The rate arithmetic
A cash-out refinance replaces your existing mortgage with a larger one. If your current rate is above market, that improves the rate on the entire balance while producing cash, which is straightforwardly good.
If your current rate is well below market, which is true for anyone who financed or refinanced during the low-rate window, a cash-out refinance means repricing the whole balance to access a fraction of it. Giving up a favorable rate on $400,000 to extract $150,000 is usually a poor trade.
A HELOC leaves the first mortgage untouched and prices only the new money. That is why HELOCs have dominated as a down payment source for the last several years, and the reasoning is arithmetic rather than fashion.
HELOC mechanics worth understanding
A HELOC is a revolving line secured by your home, typically at a variable rate tied to prime, with a draw period followed by a repayment period.
The flexibility is genuinely useful during an acquisition. You can draw for the down payment, draw again for furnishing, and repay as cash flow arrives without reapplying. That fits the actual shape of a short-term rental purchase, where money goes out in stages.
The variable rate is the corresponding risk. A rate increase raises your payment on a balance secured by your home, and the timing of that is not under your control. Size the draw so a rate increase is absorbable.
The fixed-rate alternative
A home equity loan, as distinct from a line, is a fixed-rate lump sum secured by the same equity. If you are drawing the full amount at once and have no intention of repaying quickly, the fixed structure removes the rate risk.
The tradeoff is the flexibility. You cannot draw again without a new loan, and you begin paying interest on the full amount from day one rather than only on what you have used.
For a buyer who has a firm number and a firm plan, fixed is usually better. For one who is still sizing the furnishing budget, the line is more practical.
The risk transfer nobody discusses
Both structures secure the debt against your primary residence. That is a genuine transfer of risk: a short-term rental that underperforms now threatens the house you live in.
The discipline that follows is to size the draw so that a bad first year for the rental is survivable from your income alone, without the property contributing anything. If the HELOC payment only works because the rental performs, the structure is fragile.
This is a specific instance of the general rule about reserves. If the deal only works because you skipped the reserve or maximized the draw, the deal does not work.
Model twelve months of the short-term rental producing zero net cash flow while you service both the primary mortgage and the home equity debt from income. If that is uncomfortable, reduce the draw or wait.
Other sources worth comparing
- 1031 exchange proceeds. If the capital is coming from selling another investment property, an exchange defers the gain and leaves substantially more available. The 45-day identification window is the practical constraint.
- Taxable brokerage assets. Selling triggers capital gains, but avoids adding debt secured by your home. Worth comparing on an after-tax basis.
- Securities-based lending. Borrowing against a portfolio avoids realizing gains and avoids encumbering the house, at the cost of margin risk.
- Partnership capital. Splits the down payment and the return. Settle the material participation question before structuring it.
- A prior-year tax refund. For owners already running the strategy, the refund from a first property frequently funds the second.
Running the comparison properly
The right comparison is not which source has the lowest rate. It is which source produces the best after-tax position across your whole balance sheet, given what you are giving up.
A cash-out refinance at a lower headline rate than a HELOC can still be worse if it reprices a large low-rate balance. Selling appreciated securities at a favorable rate can beat borrowing at an unfavorable one. There is no universal answer.
Run the actual numbers on your actual balances rather than applying a rule of thumb, and involve your CPA if the choice involves realizing gains. The decision is usually worth more than the effort of modeling it properly.
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Frequently asked questions
Should I use a HELOC or cash-out refinance for a rental down payment?
It depends on your existing mortgage rate. If it is well below market, a HELOC leaves the first mortgage untouched and prices only the new money. If your existing rate is above market, a cash-out refinance improves the rate on the whole balance while producing cash.
What is the risk of using home equity for a rental down payment?
The debt is secured by your primary residence, so a rental that underperforms threatens your home. Size the draw so that twelve months of zero net cash flow from the rental is survivable from income alone.
Is a home equity loan better than a HELOC?
For a buyer with a firm number and a firm plan, the fixed rate removes the risk of a variable payment increase. For one still sizing the furnishing budget, the revolving line's flexibility is more practical.