Buying Abroad: How to Adapt Your International Simulation

Buying abroad: why your buy or rent math must change

Deciding whether to buy or rent is already complex in your home country. Once you look abroad, it becomes a real quantitative challenge: loan rate (taux_pret), annual inflation (inflation_annuelle) and yearly ownership costs (montant_fn) can be radically different from what you know.

It’s no longer just about comparing a local rent to a mortgage payment. To decide if it makes sense to buy abroad or keep renting, you must adapt each simulation parameter to the local reality. The same buy or rent model with different inputs can lead to the opposite conclusion.

All examples below are general and educational. They are not personalized financial advice. Your decision to buy abroad will depend on your personal situation, tax rules and risk profile.

1. Loan rate (taux_pret): the main driver of your international simulation

Comparing local loan rates to your home benchmark

In 2024, a typical owner-occupier mortgage in France is around 3.5–3.8% over 20 years for a solid profile. Abroad, spreads are much wider:

• Country A (e.g. Germany): 3.0–3.5% over 15–20 years
• Country B (e.g. Spain): 3.6–4.2% depending on the borrower
• Country C (e.g. US): 6–7% over 30 years

In an international simulation, the parameter taux_pret must reflect the rate you can actually get as a foreign buyer, not just the average domestic rate. Banks often apply:

• A rate premium for non-resident borrowers
• A higher minimum down payment (20–30% vs 10%)
• Higher upfront fees

Numerical example: same price, different taux_pret

Imagine you hesitate between buying in your home country and buying abroad:

• Property price: €250,000 in both cases
• Loan term: 20 years
• Down payment: €50,000 (you borrow €200,000)

Home scenario (taux_pret = 3.6%, borrower insurance 0.30%):

• Monthly payment ex-insurance ≈ €1,165
• Total interest over 20 years ≈ €79,600

Foreign scenario (taux_pret = 5.5%, insurance 0.30%, typical non-resident conditions):

• Monthly payment ex-insurance ≈ €1,380
• Total interest over 20 years ≈ €130,900

Same price, same loan amount, but the higher taux_pret abroad adds over €50,000 in extra interest. In a buy or rent comparison, those interests are a pure cost and must be captured by the simulator.

How this changes the buy abroad vs rent logic

For a reference rent of, say, €1,200/month, a 3.6% rate can make buying competitive after 10–12 years of holding. A 5.5–6% rate can push the break-even point to 18–20 years, or make renting more rational if you expect to resell quickly.

In your international simulation, play with both taux_pret and loan term. Some countries use shorter terms (15 years), others much longer (30 years). A longer term reduces monthly payments but dramatically increases total cost, which a serious buy or rent calculator must show.

2. Annual inflation (inflation_annuelle): enemy of cash, ally of fixed debt

Local inflation vs euro area

inflation_annuelle is critical in any international model because it affects:

• The future path of your rent if you keep renting
• The potential value growth of the property if you buy abroad
• The real value of your future mortgage payments

In the euro area, inflation has fluctuated between roughly 2% and 5% in recent years, but some countries have experienced:

• Low inflation: 1–2% per year
• Moderate inflation: 3–4% per year
• High inflation: 8–10% per year or more

In a high-inflation country, rents and salaries may rise quickly, but the currency loses purchasing power. If your mortgage rate is fixed, inflation slowly erodes the real burden of your repayments.

Example: inflation_annuelle and your future rent

You’re comparing buying abroad vs renting in a country where:

• Current rent: €1,000/month
• inflation_annuelle (and average rent indexation): 4% per year

After 10 years, assuming you keep renting:

• Theoretical rent ≈ 1,000 × (1.04)¹⁰ ≈ €1,480/month
• That’s +€480 per month vs today

Cumulative rents over 10 years at 4% annual increases are close to €145,000. If, instead, you had bought with a fixed mortgage of €1,300/month, the gap between rent and mortgage narrows over time.

inflation_annuelle and the real cost of your mortgage

Suppose you borrow €200,000 at 5% over 20 years in a country where average inflation_annuelle is 4%:

• In nominal euros, you repay the full €200,000 plus interest
• In real terms (inflation-adjusted), the burden is much lower

If your income broadly tracks inflation, your mortgage payment becomes lighter in your budget every year. In a buy or rent simulation, a high-inflation country with moderate fixed rates can make long-term buying attractive, even if the headline taux_pret looks expensive compared with home.

The opposite risk: variable rates and inflation spikes

In several markets, mortgage rates are variable or indexed to inflation. If you underestimate inflation_annuelle in your simulation, you can easily understate:

• How far your mortgage payment might climb
• How much stress a period of high inflation could put on your budget

For a realistic international buy or rent analysis, test at least three inflation_annuelle paths (e.g. 2%, 4%, 6%) in the simulator, and check how your future rents, real mortgage burden and savings evolve.

3. Yearly ownership costs (montant_fn): local taxes and charges

What montant_fn should capture abroad

In an international setting, the parameter montant_fn should aggregate:

• Property tax (or local equivalent)
• Condo fees and building maintenance
• Mandatory property insurance (excluding borrower insurance)
• Any local occupancy or second-home taxes

In France, property tax can range from about €450 to over €5,000 per year depending on city and property value. Abroad, some countries have:

• Very low property taxes (0.1–0.3% of property value per year)
• High property taxes (1–2.5% of property value)
• Heavy condo fees (amenities, security, pools, services)

Example: comparing montant_fn across two countries

You buy a €300,000 apartment.

Country X (low property tax):

• Property tax: 0.2% of price = €600/year
• Condo fees: €100/month = €1,200/year
• montant_fn total ≈ €1,800/year

Country Y (high tax, expensive condo):

• Property tax: 1.5% of price = €4,500/year
• Condo fees: €200/month = €2,400/year
• montant_fn total ≈ €6,900/year

Over 10 years, the difference in montant_fn is:

• Country X: about €18,000
• Country Y: about €69,000

That’s a gap of around €51,000. Any serious international buy or rent simulation must include this cost, otherwise the result is meaningless.

Indexation of taxes and charges

montant_fn is not static. In many countries, property taxes and charges increase over time due to:

• inflation_annuelle
• Periodic property revaluations by local authorities
• Major building works (façade, energy upgrades, safety compliance)

If you set inflation_annuelle at 4%, it is reasonable to grow montant_fn by at least 2–4% per year in your simulation, based on local history.

4. Full case study: buy abroad vs rent over 15 years

Starting assumptions

You plan to move abroad and stay at least 15 years. You’re comparing:

• Continuing to rent
• Buying an apartment in a major foreign city

Property data:

• Purchase price: €280,000
• Down payment: €60,000
• Loan amount: €220,000
• Term: 20 years
• taux_pret: 5.2% (non-resident conditions)

Recurring costs if buying:

• Initial montant_fn (property tax + charges): €3,500/year
• inflation_annuelle estimate: 3.5%/year (also applied to montant_fn)

Alternative if renting:

• Current rent: €1,200/month
• Rent indexation ≈ inflation_annuelle = 3.5%/year

Step 1: mortgage payment

With a 5.2% taux_pret over 20 years on €220,000:

• Monthly payment ex-insurance ≈ €1,475
• Total interest over 20 years ≈ €134,000

Over 15 years, you’d pay about 1,475 × 12 × 15 ≈ €266,000 in mortgage payments (capital + interest), with interest front-loaded in the early years.

Step 2: rent trajectory if you keep renting

Starting rent: €1,200/month, with 3.5% inflation_annuelle.

After 15 years:

• Rent ≈ 1,200 × (1.035)¹⁵ ≈ €1,900/month

Cumulative rents over 15 years with 3.5% annual increases are roughly €275,000–280,000 — similar to total mortgage outflows over the same period.

Step 3: cumulative montant_fn

Initial montant_fn: €3,500/year, indexed at 3.5%/year like inflation_annuelle.

Over 15 years, the sum of all yearly amounts is around:

• ≈ 3,500 × (1 + 1.035 + … + 1.035¹⁴)
• About 3,500 × 21 ≈ €73,500 (the exact formula gives slightly less, around €70,000)

Step 4: global buy abroad vs rent comparison

If you buy abroad:

• Mortgage payments over 15 years ≈ €266,000
• montant_fn ≈ €70,000
• Gross holding cost (before resale, excluding upfront fees) ≈ €336,000

If you rent:

• Cumulative rents ≈ €275,000–280,000
• No montant_fn, but you build no housing equity

The raw difference is not huge. Your final decision to buy or rent will then depend on:

• The resale value of the property after 15 years (linked to inflation_annuelle and the local market)
• The investment return you might earn by investing your down payment and any monthly savings if renting
• Currency risk if your income is in one currency and the property in another

This is exactly the type of structured, quantified comparison a robust international simulation should provide.

5. How to set up an accurate international simulation

Choosing a realistic inflation_annuelle

• Check the country’s 10-year inflation history (central bank, statistics office)
• Test at least three scenarios in the simulator: low, base, high (e.g. 2%, 4%, 6%)
• Index both rents and, partly, montant_fn to inflation_annuelle

Feeding a realistic taux_pret for a foreign buyer

• Contact one or two local banks or brokers specialized in non-resident mortgages
• Note the headline rate, maximum term, borrower insurance and fees
• In your buy or rent simulation, use a conservative taux_pret if you expect rates to rise

Estimating montant_fn in the target market

• Ask the seller/agent for recent property tax bills, condo charges and planned major works
• Enter the full yearly amount into the montant_fn field of your simulator
• Apply an annual uplift consistent with inflation_annuelle and local history

By combining these three parameters — inflation_annuelle, taux_pret and montant_fn — you get a far more reliable view of the true long-term cost of buying abroad versus renting.

6. Using an international-ready buy or rent simulator

To compare buy abroad vs rent objectively, a simplified spreadsheet is rarely enough. A dedicated tool like a professional buy or rent simulator should let you:

• Freely adjust taux_pret by country and borrower profile
• Input a country-specific inflation_annuelle
• Enter a realistic montant_fn and its yearly growth
• Compare the buying scenario to a renting scenario where spare cash is invested (ETFs, savings, etc.)

There is never a universal right answer — whether you should buy or rent abroad depends on your holding period, tax situation, risk appetite and life plans. But a well-calibrated international simulation drastically reduces guesswork and emotional bias.

This article is for information only and does not constitute personalized investment advice. To refine your assumptions (inflation_annuelle, taux_pret, montant_fn), test multiple countries and see after how many years buying could outperform renting in your specific case, use our dedicated comparison tool.

Simulate your situation on buy-or-rent.net