The math
Buying a house is not a decision. It is a trade with a break-even year.
Renting is not throwing money away, and buying is not automatically building wealth. Both cost money. The only question worth asking is how long you have to stay for the trade to work, and that number moves enormously with assumptions nobody tells you to check.
The hole you start in
Before appreciation, before equity, before anything, there is a round trip cost that nobody puts on a fridge magnet.
Worked example
$450,000 home, 20% down, 6.50% mortgage over 30 years, against $2,300 a month in rent
- Monthly principal and interest
- $2,275
- Cash required at closing
- $101,250
- Round trip transaction cost
- $42,750
- As a share of the down payment
- 48%
- Years of appreciation just to cover it
- 2.7
2.5% going in and 7.0% coming out. You have to stay long enough for appreciation to dig you out of a hole worth nearly half your down payment before you are even level.
This is the number that decides most of the answer, and it is the one nobody mentions when they tell you renting is throwing money away. Selling costs roughly 7% in agent commission and fees. You pay it on the whole value of the house, not on your equity.
What the renter is actually doing
A fair comparison has to give the renter the money the buyer spent. That means the down payment and closing costs go into a portfolio on day one, and any month where owning costs more than renting, the difference gets invested too.
It also has to work the other way. A mortgage payment is fixed while rent rises, so eventually owning becomes the cheaper month and the owner has surplus cash. That gets invested at the same rate. Only crediting one side is how most rent-versus-buy comparisons quietly reach the conclusion they started with.
| Year | Home value | Owner net worth | Renter net worth | Gap |
|---|---|---|---|---|
| 1 | $465,750 | $77,171 | $119,842 | $-42,670 |
| 3 | $498,923 | $116,896 | $159,340 | $-42,443 |
| 5 | $534,459 | $160,047 | $202,164 | $-42,117 |
| 10 | $634,769 | $285,142 | $325,920 | $-40,779 |
| 15 | $753,907 | $439,921 | $478,435 | $-38,514 |
| 20 | $895,405 | $643,322 | $678,406 | $-35,084 |
| 30 | $1,263,057 | $1,339,493 | $1,363,366 | $-23,873 |
Owner net worth is what you would walk away with after selling, so it is net of the 7% exit cost and the remaining mortgage balance. On these assumptions the buyer never catches up within thirty years, though the gap narrows steadily from $42,670 to $23,873.
That result is not a claim that buying is a mistake. It is a claim about these assumptions, and the whole point of the essay is that the assumptions are the argument.
Four numbers decide everything
Change one at a time and watch the answer move from never to four years.
Home appreciation. The single most powerful input, and the one people are most confident about without evidence.
| Annual appreciation | Break-even |
|---|---|
| 1.0% | never within 30 years |
| 2.0% | never within 30 years |
| 3.5% | never within 30 years |
| 5.0% | year 6 |
| 6.5% | year 4 |
The mortgage rate. The same house at 4% and at 8% is not the same decision.
| Mortgage rate | Break-even |
|---|---|
| 4.00% | year 5 |
| 5.00% | year 7 |
| 6.50% | never within 30 years |
| 8.00% | never within 30 years |
What rent actually costs. Not what you would like to pay, but what the equivalent home rents for.
| Monthly rent | Break-even |
|---|---|
| $1,800 | never within 30 years |
| $2,300 | never within 30 years |
| $2,800 | year 6 |
| $3,300 | year 4 |
What the renter earns on the money. This is the one nobody models, and it is nearly as powerful as appreciation.
| Investment return | Break-even |
|---|---|
| 4.0% | year 8 |
| 5.5% | year 11 |
| 7.0% | never within 30 years |
| 8.5% | never within 30 years |
Read those four tables together and the honest conclusion is uncomfortable: anyone who tells you buying is obviously better, or obviously worse, is telling you about their assumptions rather than about houses.
The break-even ranges from four years to never, on the same house, at the same price, depending on four numbers none of which you can know in advance.
The renter's discipline problem
There is a serious objection to everything above, and it is behavioral rather than arithmetic.
The renter in this model invests $101,250 on day one and keeps investing the monthly difference for thirty years without once dipping into it. Almost nobody does that. A mortgage is a forced savings plan with a bank enforcing it, and the equity accumulates whether you are disciplined or not.
That is a real advantage and it does not show up anywhere in the tables. If the realistic alternative is not investing the difference but spending it, buying wins comfortably in most scenarios, and the arithmetic above is answering a question you were never actually facing. Be honest with yourself about which person you are, because the model assumes the disciplined one.
What the model leaves out
Everything that is not money. Security of tenure, the ability to paint a wall, not having a landlord sell the place out from under you, schools, proximity to family. These are real and they are not irrational. They are just not financial, and dressing a lifestyle preference in financial language is how people talk themselves into bad trades.
Mobility. The round trip cost is a tax on changing your mind. If there is a real chance you move in under five years, the arithmetic rarely works and the flexibility has genuine value.
Maintenance is a range, not a number. We assume 1.0% of value a year. Some years it is nothing and some years it is a roof. Owners systematically underestimate this because the average feels like the typical.
Tax treatment. We ignore mortgage interest deductibility, which most filers no longer benefit from since the standard deduction rose, and we ignore the capital gains exclusion on a primary residence, which is genuinely valuable for long holders. The first omission is conservative toward renting, the second toward buying.
Leverage cuts both ways. A 20% down payment means a 5 times levered bet on one asset in one city. That amplifies appreciation, which everyone notices, and it amplifies the opposite, which people discover.
How to actually use this
- Find what the home you would buy rents for. Not a cheaper one. The same one.
- Add the round trip cost, roughly 10% of the price, and ask how many years of appreciation covers it at a rate you would defend rather than hope for.
- Ask honestly how long you will stay. If the answer is under five years, the arithmetic almost never works.
- Ask honestly whether you would invest the difference. If not, buy, and stop reading essays like this one.
- Then decide, knowing it is a trade with a break-even rather than a milestone you are behind on.
Renting is not throwing money away. You are buying housing, the same as a homeowner buying it from a bank at 6.50% interest. The question was never whether one of them is wasteful. It is which one costs less over the period you will actually be there.