Buy a house or invest in Belgium? We ran the numbers
Buying a home feels like the grown-up move, and rent feels like money you never see again. So in Belgium, buying a house vs investing can look like an easy question.
But a home costs far more than its mortgage, and the money a renter keeps can go into an ETF. We ran both on a €300,000 flat over 25 years, and they stay level for about 15 of them. After that, the result depends on how long you stay, what your rent would be, and whether the renter really invests the difference.
Renting and investing vs buying: who's ahead after 25 years
On a €300,000 flat in Flanders, buying and renting are level for 15 years, and after 25 years the renter leads by about €52,000 after tax. The table compares the buyer's home, minus the remaining mortgage, with the renter's portfolio.
| After | Buyer: home minus mortgage | Renter: portfolio |
|---|---|---|
| 10 years | €234,524 | €228,530 |
| 15 years | €345,231 | €349,056 |
| 25 years | €628,133 | €734,120 |
| 25 years, after tax | €628,133 | €680,564 |
The last row assumes the renter sells everything at once and pays the 10% capital gains tax above the €10,000 exemption. Selling over several years would cost less. Selling your own home is in principle not taxed.
The table also stops just as the buyer's position improves. After 25 years the mortgage is gone, and running the home costs about €576 a month. The renter is paying about €1,608. That €1,032 gap continues every month from then on.
These are the assumptions behind the table:
- The flat: €300,000, close to the average Flemish flat of €300,349 in the first nine months of 2026 (Fednot figures).
- The mortgage: a 20% deposit, then €240,000 over 25 years at 3.65%. We derived that rate from the Belfius Pricemeter, which says €1,500 a month over 25 years borrowed €296,000 in June 2026.
- The home: grows 3% a year, which is our assumption.
- The rent: €1,000 a month, close to the Flemish average of €1,006 in the first half of 2026, rising 2% a year.
- The renter: invests the money the buyer spends up front, plus the monthly difference, and pays 0.12% transaction tax on each purchase.
- The return: 7% a year, before the capital gains tax.
That 7% is an assumption, not a promise. For reference, the MSCI ACWI IMI index, which covers more than 8,000 companies worldwide, has returned about 8% a year in euro since May 1994, based on the IMIE ETF after its 0.17% fee. You can check that in Backtest, our free tool. Those values are simulated from the index before the ETF launched in 2011. The gap grows the way it does because of compound interest, and past returns don't predict what ETFs will return.
What a €300,000 home costs before you get the keys
A €300,000 flat in Flanders takes more than €71,000 before you get the keys: a €60,000 deposit, €6,000 in tax and about €5,250 in other costs. Belgium's three regions tax the same flat differently.
| Region | Tax on your only home | On €300,000 |
|---|---|---|
| Flanders | 2% | €6,000 |
| Wallonia | 3% | €9,000 |
| Brussels | 12.5%, first €200,000 exempt | €12,500 |
These rates from Notaris.be come with conditions, starting with this being your only home and you living in it. The full rate is 12% in Flanders and 12.5% in Wallonia and Brussels.
Flanders plans to raise its 2% to 3% for sales agreements signed from 1 January 2027, which would add €3,000 on this flat. On 2 October 2026, Notaris.be said this still had to become law.
Our €5,250 follows the notaries' Flemish cost sheet, which shows €4,370 besides the tax on a €250,000 home. It covers the purchase deed only. Your mortgage deed costs extra, and our model leaves that out, which slightly favours the buyer.
A deposit you'll need soon is also short-term money. If you plan to buy within five years, it belongs in a savings account rather than in shares, because a crash in the year you need it could cost you the house.
Owning costs more than the mortgage
Owning this flat costs about €1,570 a month, not the €1,213 mortgage payment. Maintenance, property tax and insurance add about €358 a month.
We use 1% of the price a year for maintenance, plus €1,000 of property tax and €300 of insurance, all rising 2% a year. The tax and insurance figures are our own estimates, and an old house can easily need more maintenance.
So comparing rent with a mortgage payment gives the wrong answer. KU Leuven economist Geert Goeyvaerts told VRT that doing so is comparing apples with oranges. Here, the renter pays €1,000 and keeps about €570 a month the buyer doesn't have, on top of the €71,250 up front.
Since 1 January 2025, no Belgian region gives an income tax benefit on a new mortgage, so none is in our model.
The winner changes with where you live
Where you live can flip the result, mainly because rent differs so much. On the same model, the renter wins in Flanders, and the buyer wins in Wallonia and Brussels.
| Region | Flat price | Rent a month | Monthly cost of owning | Ahead after 25 years, after tax |
|---|---|---|---|---|
| Flanders | €300,000 | €1,000 | €1,571 | Renter, by €52,431 |
| Wallonia | €216,000 | €910 | €1,161 | Buyer, by €91,930 |
| Brussels | €300,000 | €1,400 | €1,571 | Buyer, by €267,726 |
The flat prices follow the Fednot averages for the first nine months of 2026: €216,239 in Wallonia and €301,666 in Brussels. The rents are the first-half 2026 averages reported by Federia: €910 in Wallonia and €1,401 in Brussels.
Read this table with care. The Brussels rent covers all housing types, including houses far bigger than this flat, so the buyer's lead there is overstated. Rent on the flat you'd actually buy is the first number to look up for your own case.
Three assumptions that flip the result
Nobody can name the winner in advance, because small changes in three numbers move the result by more than €100,000. All of these use the Flemish example, after 25 years and before tax, where the renter starts €105,987 ahead.
| Change | Who's ahead after 25 years |
|---|---|
| Homes grow 2% a year instead of 3% | Renter, by €241,938 |
| Homes grow 4% a year instead of 3% | Buyer, by €65,631 |
| Shares return 5% a year instead of 7% | Buyer, by €135,115 |
| Rent is €1,200 instead of €1,000 | Buyer, by €81,316 |
The two sides are level when shares return about 6.2% a year. Lower average returns than history are entirely possible, and so is a long bad stretch for shares.
History doesn't settle it either. Belgian home prices grew about 4.36% a year from Q2 1994 to Q1 2026, according to the BIS index, while IMIE's index returned about 8.07%. Put those two rates in our model, and the home reaches €871,913. The portfolio reaches €909,817, or €838,692 after tax, which leaves the buyer about €33,000 ahead.
Shares grew almost twice as fast, and the buyer still wins, because that 4.36% applies to a whole home bought mostly with the bank's money. This isn't a replay of history: it applies long-run averages to 2026 costs and ignores the much higher mortgage rates of the 1990s.
Renting only wins if you really invest the difference
The renter's lead depends on investing about €570 every month for 25 years, and that is the hardest assumption in the whole comparison. A bank collects your mortgage payment whatever you feel like doing, while an ETF plan stops the moment you stop it.
| What the renter invests | Portfolio after 25 years | Compared with the buyer's €628,133 |
|---|---|---|
| The €71,250 and all of the monthly difference | €734,120 | Renter ahead by €105,987 |
| The €71,250 and half of the monthly difference | €560,180 | Buyer ahead by €67,953 |
| The €71,250 and none of the monthly difference | €386,241 | Buyer ahead by €241,892 |
All three rows are before tax. A mortgage works as a savings plan you can't skip, and for many people that is worth more than a few points of return.
So a renter's plan has to be automatic. Periodic investing on a fixed day removes the monthly decision, and you can pick an amount you can keep up and raise it later. If you do it yourself through a broker, our DCA guide covers the setup.
Keeping up a monthly investment for 25 years is exactly what we built Curvo for. You set an amount, and the money is invested automatically in a portfolio of index funds, without you placing an order or paying the transaction tax. That works for a renter, and just as well for a buyer who keeps investing next to the mortgage. Curvo is not the cheapest way to invest: the fee is 1% a year on portfolios below €50,000 and falls to 0.60% above €250,000. See how monthly investing with Curvo works.
How long you need to stay for buying to pay off
Plan on seven to ten years. Buying costs you when you buy and again when you sell, so a short stay leaves you behind the renter. We assume 3% in selling costs.
| Sell after | Buyer behind the renter by |
|---|---|
| 2 years | €14,924 |
| 5 years | €8,882 |
| 7 years | €6,465 |
| 10 years | €6,102 |
On these amounts, €6,000 after ten years is close to a tie, though the gap never fully closes in this example. A new job, a relationship or a move abroad can turn a purchase into an expensive few years.
When we'd buy, and when we'd rent and invest
We'd buy when three things are true, and rent and invest automatically when any of them isn't.
- You'll stay for at least seven to ten years. Shorter stays favour the renter in our example.
- Your emergency fund survives the deposit. A new home brings surprise bills, and that buffer belongs in one of the best savings accounts, not in the walls.
- You can pay the monthly bill and still invest something. A small automatic amount next to a mortgage keeps you diversified, because otherwise most of your wealth sits in one building.
Some of this never shows up in a table. A home gives you security from a landlord ending your lease, and freedom to change the place you live in. Renting gives you the freedom to leave. Those are real, and they can reasonably outweigh €50,000 over 25 years in either direction.
Plenty of people weigh this up with friends around them buying. When we first published this article in 2019, Émile-Victor, a co-founder of the Brussels startup Marker.io, was doing exactly that.
Buying a second home to rent out is a different question
This article is about the home you live in. A second property brings leverage, tenants, vacant months and different tax rules, so we compare it separately in index investing vs renting out real estate. If you simply want property in your portfolio without being a landlord, a real estate ETF is the simpler route.
Buying a house vs investing: the conclusion
Buying a house vs investing has no single answer in Belgium. On a €300,000 Flemish flat the two stay level for about 15 years, and the renter ends about €52,000 ahead after tax. Rent, region and home prices can each turn that around.
The two questions you can actually answer are how long you'll stay and whether you'd really invest the difference every month. If you'd stay and rent near you is high, buying is a strong choice. If you may move, renting wins, as long as the investing happens automatically.
Either way, the plan doesn't have to be a house or ETFs. If you plan to stay, we'd buy and keep a monthly investment going next to the mortgage. With Curvo, you can set that up in a few minutes.