Mortgage Rates and Strategy: A Developer's Homework

Every Time I Open a Real Estate App, I Sigh

I'm renting in Seoul with a jeonse deposit of 270 million won (about $200K). Jeonse is a uniquely Korean system where you put down a massive deposit instead of paying monthly rent -- the landlord invests your deposit and returns it when you leave. No monthly rent is nice, but I keep wondering: couldn't this money buy a small apartment somewhere on the outskirts?

So I installed a real estate app. I probably open it three times a week. (Prices seem to go up every time I look.)

But buying a home means taking out a mortgage. No 5th-year developer is buying property with cash. So I started studying interest rates.

What Are the Rates Actually Like?

As of August 2025, Korean mortgage rates range from 3.5% to 5.2% annually. Varies by bank, varies by conditions. Those "3% mortgage available!" ads? That's the best-case preferred rate -- almost no one actually qualifies.

I plugged in my numbers. 5th-year salaried employee, annual income 68 million won (~$50K), credit score 847, no existing property. KakaoBank simulation: 4.17%. Hana Bank: 4.38%. Woori Bank: 4.52%. Same person, 0.3 percentage points difference between banks.

0.3 points sounds trivial, but on a 300-million-won loan over 30 years, the total interest difference is 18.47 million won. That's a car.

Fixed vs Variable: The Hard Choice

Fixed rates are currently 4.3-4.8%. Variable rates: 3.8-4.3%. Variable is about 0.5 points cheaper. "Variable is cheaper now, so let's go variable" -- apparently that's the biggest trap.

People who took variable-rate loans in 2022 got crushed when rates spiked. But right now rates are trending down, so variable might actually work out. Honestly, I don't know who's right. Even economists disagree.

My plan is a hybrid: 5-year fixed then switch to variable. See what rates do in those 5 years and decide then. Which is basically gambling, but with extra steps.

The Loan Ceiling Was Lower Than Expected

Korea has DSR (Debt Service Ratio) regulations that cap how much you can borrow. With my income of 68 million won, at a 40% DSR limit, annual principal-plus-interest payments max out at 27.2 million won. Over a 30-year term, that translates to roughly 420 million won in borrowing capacity.

But my existing student loan balance of 7.3 million won cuts into that. Reduces the ceiling by about 2 million won. Maybe I should pay off student loans first.

I Punched the Calculator

Say I buy a 350-million-won apartment. Down payment: 100 million (pulled from my jeonse deposit). Loan: 250 million. Rate: 4.2%, 30-year amortization.

Monthly payment: 1,223,000 won. Total interest over 30 years: 190.28 million won.

The interest is almost as much as the principal. Over 30 years, I'd pay 440 million total. I stared at the screen for about 5 minutes after seeing that.

The Housing Lottery Variable

In Korea, there's a government housing subscription savings system (cheongnyak). I've been depositing 100,000 won monthly for 7 years. Current balance: 8.42 million won. But I recently learned that my deposit level makes me barely competitive. I don't qualify for special priority, and for general allocation, it's basically a lottery.

Honestly, that money probably would've done better in an ETF. But closing the subscription account feels psychologically impossible. "What if I win?" The eternal maybe.

There's No Conclusion Here

The more I study, the less I know. Buy now or wait? Rates could drop, or climb back up. Prices too. One thing's certain: if I don't decide, time just passes.

I scheduled a bank consultation for next week. Going in person to get exact rates for my profile. Online simulations might differ from reality, supposedly. Though the advisor will obviously say "yes, buy now." That's their job.