HELOCs Explained: Borrowing Against Your House, and When It Makes Sense
A home equity line of credit lets you borrow against the value you've built in your home. Here's how a HELOC works, what it costs, the risks most people underestimate, and when it's a reasonable tool.
In the buy, borrow, die post, the very rich borrow against their stock portfolios instead of selling. Most households don’t have a $10 million portfolio, but many have something else worth borrowing against: their house. The most common way to do that is a home equity line of credit, or HELOC.
What a HELOC is
Your equity is what your home is worth minus what you still owe on the mortgage. If your house is worth $500,000 and you owe $300,000, you have $200,000 of equity.
A HELOC is a revolving line of credit secured by that equity. It works more like a credit card than a regular loan. The lender approves a maximum amount, and you borrow what you need, when you need it. You pay interest only on what you’ve actually drawn, and as you pay it down, that room opens up again.
How much you can borrow
Lenders usually cap your combined loan-to-value (CLTV) at around 80% to 85%. That means your mortgage plus the HELOC can’t exceed that share of the home’s value.
Using the example above, at an 85% limit:
- 85% of $500,000 = $425,000
- Minus the $300,000 mortgage = a HELOC of up to $125,000
Your credit score, income and existing debt also affect how much a lender will approve and at what rate.
The two phases
A HELOC has two stages, and the switch between them catches a lot of people off guard:
- The draw period, often 10 years. You can borrow freely, and many HELOCs let you pay only the interest during this time, so monthly payments look small.
- The repayment period, often 20 years. You can’t borrow anymore, and you start paying back principal plus interest. Payments can jump sharply, sometimes doubling or more overnight.
If you’ve been making interest-only payments on a large balance, plan for that jump years ahead.
What it costs
Most HELOCs have a variable rate tied to the prime rate, plus a margin set by the lender. When the Federal Reserve raises rates, your HELOC rate rises with it, usually within a billing cycle or two. That happened to many borrowers in 2022 and 2023, when payments on the same balance climbed quickly.
HELOC rates are usually higher than first mortgage rates but much lower than credit cards or personal loans, because your house backs the debt. Watch for other costs too: appraisal fees, closing costs, annual fees, and early-closure fees if you shut the line within a few years.
The tax angle
HELOC interest is deductible only if you itemize and the money was used to buy, build or substantially improve the home that secures the loan. Using a HELOC to pay off credit cards, cover tuition or buy stocks doesn’t make the interest deductible as home mortgage interest.
The risks
- Your house is the collateral. If you can’t make the payments, the lender can foreclose. Credit card debt doesn’t put your home at risk; a HELOC does.
- The line can be frozen. If home prices drop or your finances weaken, the lender can reduce or freeze your line. Many banks did exactly that in 2008 and again briefly in 2020, right when borrowers wanted the money most.
- Rising rates. A variable rate means you don’t know what your payment will be in five years.
- It’s easy to overspend. Because the money is always available, it’s tempting to use it for vacations and cars, turning home equity into long-term debt on things that lose value.
When a HELOC makes sense
A HELOC tends to work well for:
- Home improvements, especially ones that add value. This is also the case where the interest can be deductible.
- Replacing high-interest debt, if you’ve fixed the habits that created it. Moving a 25% credit card balance to a much lower rate can save a lot, but only if the cards stay paid off.
- A backup emergency fund. Some people open a HELOC and leave it at zero as a safety net. Keep in mind the lender can freeze it in a downturn, so it shouldn’t replace cash savings.
It’s riskier for investing. Borrowing against your home to buy stocks is a smaller version of buy, borrow, die, but without the cushion. If the market falls, you still owe the full balance, and your home is on the line.
HELOC vs. the alternatives
- Home equity loan: a lump sum with a fixed rate and fixed payments. Better if you need a known amount once, like a roof replacement.
- Cash-out refinance: replaces your whole mortgage with a bigger one. It usually only makes sense if the new mortgage rate is close to or below your current one.
- HELOC: best when you need flexible access over time and can handle a rate that moves.
The short version
A HELOC lets you borrow against your home’s equity as you need it, usually at a lower rate than unsecured debt. It’s a useful tool for home improvements and for replacing expensive debt. But the rate is variable, payments can jump when the draw period ends, the lender can freeze the line, and your house is the collateral. Borrow for things that last, and have a plan to pay it back.
Not financial advice — just an explanation of how HELOCs work. Talk to a lender or financial professional about your own situation.