How much does a €300,000 flat actually cost?
The true cost of a property bought with a mortgage is the sum of every expense from signing the contract to paying off the last instalment — including interest, insurance, notary fees, taxes, and maintenance. According to ECB data (October 2025), the average eurozone mortgage rate sits at 3.31%. At that rate, a €300,000 loan over 25 years costs roughly €445,000 in total repayments — nearly 1.5 times what you borrowed.
Scenario: a 60 m² flat in a major European city
Someone is looking for a flat in Berlin. 60 m² in the city centre costs around €446,000 (approx. €7,430/m² according to Numbeo, March 2026). In Amsterdam — €561,000. In Paris — over €757,000. Even with a 20% deposit, a Berlin mortgage comes to €357,000. At 3.3% over 25 years, the monthly payment is roughly €1,740. Total repayment: approximately €522,000 — for a flat that cost €446,000.
That calculation covers the mortgage payment alone. It doesn't include the notary, property transfer tax, estate agent fees, renovation, building insurance, or monthly service charges. Each of these looks like a minor expense on its own. Together they can add €30,000–80,000 to the price on the listing.
These are facts. Not to discourage you — but so you know what you're signing up for before you sign.
Why is it so hard to calculate the true cost of buying?
The complexity of property purchase costs comes from the fact that they're spread across time and split between a dozen institutions. There is no single place where you see the full bill. The bank shows you the monthly payment. The developer shows you the price per square metre. The notary shows you their fee. Nobody shows you the total.
The cost fragmentation effect in property decisions
The cost fragmentation effect is the brain's tendency to evaluate each expense in isolation, without summing them up. When costs are scattered across time (agent fee now, transfer tax next week, renovation next month, first payment in two months), each passes through the mental filter of "can I afford this?" separately — and passes it more easily than if you saw one full figure.
Then there's social pressure. "Everyone buys eventually." "Renting is throwing money away." "Your mortgage payment is like rent, but at the end you own something." These phrases sound reasonable. They're based on incomplete maths.
Let's be honest — nobody wants to hear that a €300,000 flat costs over half a million. But I'd rather you knew that now than discovered it in year three of your repayments.
Adam, założyciel Martia
From the founder
Before I built Martia, I tracked my finances in a spreadsheet. When I analysed mortgage costs, my sheet had 47 rows of expenses. Forty-seven. And I was still missing two items I only discovered at the notary's office. The problem isn't that people can't do maths. The problem is that nobody gives them the full list.
European mortgage market — March 2026
Sources: ECB 2025, Eurostat 2025
Not sure how much you actually spend each month?
Before taking on a mortgage, find out where your money goes today. Martia connects to your bank and shows your full spending picture — no manual entry required.
Does 'mortgage payment equals rent' really mean buying is better?
The comparison "my mortgage payment would be the same as my rent" is one of the most common oversimplifications in European property markets. It sounds logical: if you're already paying €1,500 in rent, why not pay €1,500 towards a mortgage and own something at the end? But this comparison ignores a dozen variables.
Myth vs. reality
Myth: "A mortgage payment is the same as rent, but at the end you own the property. Renting is throwing money away."
Reality: A mortgage payment of €1,500 for a €300,000 property is only part of the picture. Add insurance, service charges, maintenance reserves, and repairs — the true monthly cost rises to €2,000–2,300. In the early years, most of each payment goes to interest, not equity. After 5 years of repaying a €300,000 loan at 3.3%, you've built roughly €45,000 in equity — while paying about €50,000 in interest. According to data from Meilleursagents (2026), the average break-even point between buying and renting in France is 12 years and 3 months. In Paris, it's over 21 years.
This doesn't mean buying never makes sense. It does — but only when you compare full costs of both options. Renting for €1,200 and investing the difference in index funds for 10 years can produce a better financial outcome than buying with a 25-year mortgage — especially when property prices stagnate. According to Eurostat (Q2 2025), EU house prices have risen 60.5% since 2010, while rents increased only 28.8%. That gap isn't guaranteed to continue.
Do the maths. Not on the estate agent's calculator — on yours.
When does a mortgage actually make sense — and when is it better to wait?
A mortgage makes sense when three conditions are met simultaneously: you have stable income, you have an emergency fund separate from your deposit, and your total housing cost (mortgage + insurance + charges) doesn't exceed 30% of your household's net income. If any one of these is missing — it's worth waiting.
The Martia Full Cost of Housing Method
The Full Cost of Housing Method is a calculation approach where you don't just look at the monthly payment, but at every expense tied to the property over the full mortgage term: interest, insurance, transaction costs, renovations (every 10–15 years), service charges, and the opportunity cost of your locked-up deposit. Only this total, divided by the number of months, gives you a true "monthly cost of housing" comparable to rent.
When does a mortgage NOT make sense?
1. Your total housing cost exceeds 35% of net income. According to Eurostat (2024), the average European spends 19% of disposable income on housing. In Greece, it's 36% — and 28.9% of Greeks are classified as housing-cost overburdened. Don't join that statistic.
2. You don't have an emergency fund covering 6 months of expenses. Your deposit is not your emergency fund. If you put €60,000 down and have €2,000 left in your account — every broken appliance or job loss becomes a crisis.
3. You're planning to move within 5–7 years. Transaction costs of 5–13% mean you need significant price appreciation just to break even. According to Meilleursagents (2026), the break-even period between buying and renting averages 12 years across France. In expensive cities, it's over 20.
4. You're buying because "everyone buys". Social pressure is the worst financial adviser. Germany has the lowest homeownership rate in the EU — below 50% — and it's one of the wealthiest countries on the continent. Renting is not failure.
When is it worth taking a mortgage?
When your total housing cost (payment + insurance + charges) is no more than 30–35% of your household's net income. When you have an emergency fund covering 6 months beyond your deposit. When you plan to stay in the same city for at least 7–10 years. And when, after applying the Full Cost of Housing Method, buying still comes out ahead of renting and investing the difference.
How to prepare for a mortgage — concrete steps
Preparing for a mortgage is a process that should start 12–18 months before the planned purchase. This is not a spontaneous decision — it's the most expensive commitment most people will ever make.
Step 1: Know your spending — truly
Before approaching a bank, you need to know how much you actually spend each month. Not roughly — precisely. The bank will review 3–6 months of your transaction history. Better that you see it first. Controlling your household budget is the starting point.
Step 2: Build an emergency fund BEFORE saving for a deposit
The order matters. Emergency fund first (6 months of expenses), then the deposit. Not the other way around. A 20% deposit on a €300,000 flat is €60,000. An emergency fund at €2,500/month in expenses is another €15,000. That's €75,000 before you start talking to banks.
Step 3: Calculate the full cost, not just the payment
Take the monthly payment from the bank's calculator and add: home insurance (~€40/month), life insurance if required (~€50/month), service charges (~€300/month), utilities (~€200/month). Only this sum is your true "cost of housing". Example: €1,500 payment + €590 in fixed costs = €2,090 per month.
Step 4: Stress-test your affordability — without the bank
For 6 months before applying, transfer the amount equal to your projected payment + costs into a separate savings account every month. If you can set aside €2,090 for six months and live on the rest — you have your answer. If after two months you're dipping into that money — you also have your answer.
This is the best affordability simulation you can run. No bank calculator will tell you this. Your bank account will.
Find out how much you can actually set aside — before visiting the bank
Martia automatically categorises your spending and shows how much remains after fixed costs. You'll see whether €2,000 a month in mortgage payments is realistic — or wishful thinking.
What tools help you prepare for a mortgage?
Preparing for a mortgage starts with one thing: knowing your own finances. Not with comparing bank offers, not with scrolling through property listings. With checking how much you earn, how much you spend, and how much is left.
Budgeting apps like Martia connect to your bank through secure open banking APIs (regulated under European PSD2 legislation) and show all your transactions in one place — automatically categorised. No manual entry. You see how much goes to food, transport, subscriptions, entertainment. And you see what's left.
This knowledge has concrete value. If before a mortgage you discover you're spending €300 a month on things you could cut — that's €3,600 a year. Over 2 years — nearly €7,200 closer to your deposit. Or €7,200 closer to an emergency fund that lets you sleep soundly with a mortgage.
Start with your bank's built-in mortgage calculator, or national comparison sites like Hypothekenrechner (Germany), MeilleursTaux (France), or MoneySuperMarket (UK). These show you the payment. What they don't show is how much of your income is already spoken for.
Nobody will do this for you. But the right tools can make it simple rather than painful. You know how it is with inflation and savings — time works against you. The sooner you start seeing your numbers, the sooner you make a good decision.
Sources and references
- ECB — European Central Bank, Monetary policy decision — 19 March 2026, ecb.europa.eu
- ECB — European Central Bank, Bank interest rate statistics — October 2025, ecb.europa.eu
- Eurostat, House prices and rents — Q2 2025, ec.europa.eu
- Eurostat, Housing in Europe — 2025 interactive edition, ec.europa.eu
- Meilleursagents / Connexion France, French cities where it is better to buy than rent — 2026, connexionfrance.com
- ING Think, The rent-or-buy dilemma in the eurozone, think.ing.com
- Immigrant Invest, Real estate in Europe: prices, taxes and maintenance costs — 2026, immigrantinvest.com
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