How a HELOC actually works
A HELOC is a revolving credit line secured by your home.
- Revolving means a line you can draw, repay, and draw again.
- It runs in two phases: a draw period, then a repayment period.
- The rate is usually variable, so your payment can rise.
- Your home is the collateral, so missed payments put it at risk.
- The catch: the interest-only draw period feels cheap, then the payment jumps when principal starts.
The mechanism, one piece at a time
A HELOC turns the equity in your home into a line of credit. Equity is the part of the home you own outright. Here is how the pieces fit.
It is revolving credit. Revolving means a line you can draw, repay, and draw again. You borrow what you need, not a fixed lump sum. As you pay it back, that room opens up to use once more.
The credit limit is a share of your equity. The lender adds your mortgage balance to the HELOC and caps the total against your home's value. That cap is a combined loan-to-value limit, often up to ~85%. So the more equity you hold, the larger the line.
It runs in two phases. First comes the draw period, often 10 years. You borrow as needed and usually pay interest only. Then comes the repayment period, often 20 years. You pay back principal plus interest, and you can no longer draw.
The rate is usually variable. It is tied to an index that moves with the market. When the index rises, your rate rises, and your payment rises with it. A fixed payment is not the default here.
Your home is the collateral. That is what secures the low rate. It is also the risk: miss enough payments and the lender can move to take the home. This is borrowing against the roof over your head, so treat the payment as non-negotiable.
The steps
- The lender sets your line. They check your equity, income, and credit, then cap the line against your home's value.
- You enter the draw period. For about 10 years you draw what you need and usually pay interest only on the balance you use.
- Your rate moves with the index. Because the rate is variable, the same balance can cost more next year than this one.
- The draw period closes. You can no longer borrow. The balance you carry now has to be paid down.
- The repayment period begins. For about 20 years you pay principal plus interest. This is when the payment steps up.
Two numbers decide whether this fits: what it costs and how it compares to a lump-sum loan. See what a HELOC really costs and HELOC vs. home equity loan.
The interest-only draw period feels cheap. You are only covering the interest, so the monthly cost stays low and easy to carry.
Then repayment starts and principal kicks in. The payment jumps, often sharply, on the same balance. Plan for that step-up before you draw, not after.