You’re buying a $375,000 house. You have $75,000 for a down payment. Your loan officer will show you one thing: twenty percent down, $300,000 financed, thirty years.
Nobody will show you the second option, and it isn’t exotic. It’s a first mortgage and a line of credit, arranged at closing, at 90% combined loan-to-value. It’s a structure that has been available for decades and we’ve placed many of them.
Here is what the two look like side by side.
The conventional loan
$375,000 purchase. $75,000 down. $300,000 financed at 6.25% for thirty years.
Payment: $1,847.15
With $3,000 of living expenses and $500 for taxes and insurance, the monthly obligation is $5,347.15.
Total interest over thirty years: $364,974.58.
You paid nearly $365,000 to borrow $300,000.
The other structure
Same house, same price, same rate.
- Fixed first mortgage: $237,500 at 6.25% — payment $1,462.33
- Line of credit second: $100,000
- Total financed: $337,500 at 90% combined loan-to-value
- Cash at closing: $37,500
You keep $37,500 that would otherwise have gone to the bank on day one.
Your required payment is $384.82 a month lower. That matters most on the month something goes wrong — a conventional borrower still owes $1,847.15 whatever happens.
Because the first mortgage sits at 63% loan-to-value, it is comfortably below the threshold where mortgage insurance applies.
What happens next, month by month
The $37,500 you kept goes to work immediately: $10,000 against the first mortgage, $27,500 into the line of credit.
Then income runs through the line. Every four months, $20,000 moves from the line to the first mortgage — a lump against principal, not a payment.
The first mortgage is gone in forty months. Three years and four months.
That payment — $1,462.33 — then joins everything else going against the line, and the line closes thirteen months later.
Total: 4 years and 5 months from the day you bought the house.
The interest, both sides
| Interest paid | |
|---|---|
| First mortgage, $237,500 at 6.25%, 40 months | $26,259.53 |
| Line of credit, 7.25%, 53 months | $21,008.36 |
| Combined | $47,267.89 |
$47,268 in total interest.
For comparison: at month forty — the point where this borrower owns the house outright except for the line — the conventional borrower has paid roughly $85,000 in interest and still owes about $285,000 of the original $300,000.
But nobody actually pays the minimum, do they?
Fair. So let’s compare against what people are actually told to do.
| Debt free in | Total interest | |
|---|---|---|
| Conventional, minimum payment ($75,000 down) | 30 years | $364,975 |
| Conventional, one extra payment a year ($75,000 down) | 24.6 years | $287,703 |
| Conventional, biweekly payments ($75,000 down) | 24.4 years | $284,706 |
| Conventional, $500 a month extra ($75,000 down) | 17.6 years | $195,074 |
| First + line of credit at purchase ($37,500 down) | 4 years 5 months | $47,268 |
Against $500 extra every single month for seventeen and a half years — the most disciplined version of standard advice — this structure is 13 years faster and $147,806 cheaper.
And it required half the cash to start.
Why it works, in one paragraph
A fixed mortgage takes your payment on a schedule set the day you sign. Nothing you do changes when the interest is charged, only how much principal is left underneath it.
A line of credit charges interest on the balance you are actually carrying, day by day. Money that would otherwise sit in a checking account earning nothing is instead sitting against a balance, reducing what interest is charged on.
Split the debt, and the part that responds to your cash flow can attack the part that doesn’t.
What you give up, honestly
The line has a variable rate. Not your whole mortgage — the first stays fixed at 6.25% for as long as you keep it — but the second moves. We used 7.25%. If it rises, the arithmetic gets worse.
It requires discipline. The same line that lets you pay a balance down lets you spend it back up. Nothing happens automatically.
You need to qualify for both. Two loans, two underwrites, and a combined loan-to-value a lender will accept.
And it needs monitoring. Money moves between two accounts on a schedule. Without something to check against, you cannot tell progress from the feeling of progress.
The part most people miss
In the conventional scenario, the $75,000 down payment is gone. The only way back to it is a refinance or a new line of credit you’d have to qualify for later, possibly at a worse rate, possibly at a worse moment.
In this structure, the $27,500 you put into the line is available again the next day. So is every dollar you send after it.
Same house, same rate, half the cash down, a lower required payment, and your money still reachable.
Run your own version
The numbers above are one household: a $375,000 house, $10,000 a month of income, $3,000 of living expenses. Yours are different, and the structure isn’t right for everyone.
Two things worth doing whether you ever speak to us or not:
Pull the amortization schedule on any loan you’re being offered and add up the interest column. All of it, to payoff. Most people have never seen that number.
Then ask your loan officer what a 90% combined loan-to-value structure would look like on the same purchase. If they haven’t offered it, ask why.
If you’d like us to run your actual numbers, that’s what we do — and if the answer is that the conventional loan suits you better, we’ll tell you.
And if you’d rather check us out first, we publish a list of clients who volunteered to take your call.