Rent versus buy is not payment versus payment

Only part of the payment is a cost

The principal portion of a mortgage payment moves money from one pocket to another. It is forced saving, and it is not comparable to rent. Interest, property tax, insurance, and maintenance are consumption: they are gone, in the same way rent is gone. That is the like-for-like comparison, and it is not the one the payment figures invite you to make.

Early in an amortisation schedule the split is brutal. The first years of a long mortgage are overwhelmingly interest, so the “building equity” argument is at its weakest exactly when people make it, in year one. Maintenance is the other line people leave out entirely; it does not appear on a statement, which is why it feels optional right up until the roof does not.

The down payment has a job somewhere else

A deposit is capital that stops earning whatever it was earning. Over a ten-year comparison that forgone return is frequently the second largest term after interest, and it is the one omitted from nearly every rent-versus-buy conversation held at a kitchen table.

Counting it does not settle the question against buying. Housing is a leveraged position, and leverage on an appreciating asset is powerful in the direction people are hoping for. But you cannot claim the leverage and ignore the opportunity cost of the equity that makes the leverage possible.

The break-even horizon is the answer

Transaction costs are large and they are paid twice. There are closing costs on the way in, and historically commissions and fees of around five to six percent on the way out, though seller-side commissions have become more openly negotiable. Those are fixed charges against a benefit that accrues per year, so the whole question is how many years it takes to amortise the round trip.

That is why short stays favour renting almost regardless of the market, and long stays favour buying in most of them. The variable that moves the break-even most is the price-to-rent ratio in the specific place you are looking, not the national narrative about house prices. A high ratio means you are paying a large capital sum to avoid a small rent, and the break-even stretches out accordingly.

• Add interest, tax, insurance, and maintenance, and leave principal out.
• Add the return the down payment would have earned elsewhere.
• Divide the round-trip transaction cost by the annual advantage to get the break-even year.
• Compare that year against how long you honestly expect to stay.

What actually decides it

Our position: the two variables that matter are the local price-to-rent ratio and your expected length of stay. The interest rate matters less than people think, because a rate can be refinanced and a purchase price cannot. And “building equity” is not a return, it is a savings plan with a lock on it, which is genuinely valuable to people who would not otherwise save and worth nothing to people who would.

It is also worth being honest about the shape of the thing you are buying. A house is a leveraged, undiversified, illiquid bet on one street, funded with debt, that you also live in. Wanting it anyway is entirely defensible, and the reasons are usually not financial. Just do not confuse the reasons: run the numbers, then decide how much the non-financial part is worth to you, rather than working backwards to a spreadsheet that agrees with you.