Notary fees: new vs old property, what does it really cost?

Notary fees: the hidden cost that reshapes buy or rent maths

When you compare whether it is better to buy or rent, you usually start with the listing price and the mortgage rate (around 3.6 % today). But one cost can completely change the result: notary fees.

In most markets, buying a new-build property means notary fees of about 2–3 % of the price, while an existing (old) property costs around 7–8 %. On a €250,000 purchase, that’s a difference of more than €10,000 at day one.

In the buy-or-rent.net / acheter-ou-louer.com simulator, this appears as the parameter montant_fn (total notary fees). If you underestimate this number, your buy or rent comparison will be seriously biased.

What exactly are notary fees?

“Notary fees” are mostly taxes and charges collected by the notary on behalf of the State and local authorities. They typically include:

• Transfer duties (registration taxes) – the largest part, especially on existing property.
• Notary’s fees – regulated remuneration.
• Disbursements – land registry, administrative documents, mortgage registration, etc.
• VAT on some components.

What makes the montant_fn parameter move in the simulator is mainly:

• The type of property: new vs existing.
• The purchase price.
• Whether agency fees are included in the taxable base and paid by the buyer.

Notary fees on existing property: 7–8 % of the price

For a typical existing home, the market rule of thumb is:

• 7–8 % of the purchase price in notary fees.

Example 1: existing flat at €250,000

• Purchase price: €250,000
• Assumed notary fees: 7.5 %
• montant_fn = €18,750

If you finance 100 % of price + fees with a mortgage at 3.6 % over 25 years, those €18,750 alone translate into roughly:

• Extra principal borrowed: €18,750
• Extra monthly payment: about €95 / month
• Total interest cost on these fees: around €11,000 over 25 years (insurance excluded).

So your notary fees on an existing home do not just cost €18,750 today. If rolled into the mortgage, they cost over €29,000 in real cash outflows. The simulator captures this effect as soon as you set the montant_fn parameter.

Notary fees on new-build property: 2–3 %

On a new-build (off-plan, recently built and never occupied), notary fees drop significantly to about 2–3 %.

Example 2: new-build flat at €250,000

• Purchase price: €250,000
• Assumed notary fees: 2.5 %
• montant_fn = €6,250

With the same 3.6 % mortgage over 25 years, these €6,250 mean:

• Monthly cost linked to fees: about €32 / month
• Total interest on these fees: around €3,600 over 25 years.

Compared with the existing property case, you save roughly:

• €12,500 in upfront notary fees.
• About €7,400 in interest on those fees over the loan term.

That’s close to €20,000 difference on the full horizon. In a buy or rent framework, this gap alone can flip the simulator result, especially if you compare buying vs renting and investing the capital at some investment rate.

New more expensive, old cheaper: who really wins?

New-build properties usually have a higher price per m², but lower notary fees. Existing homes are cheaper per m² but come with heavier fees and often more renovation.

Simple comparison scenario

You hesitate between:

• Existing: €230,000 + 7.5 % notary fees.
• New-build: €250,000 + 2.5 % notary fees.

Existing

• Price: €230,000
• Notary fees (7.5 %): €17,250
• montant_fn = €17,250
• Total to finance (before renovation): €247,250

New-build

• Price: €250,000
• Notary fees (2.5 %): €6,250
• montant_fn = €6,250
• Total to finance: €256,250

Financing gap: €9,000 in favour of the existing property, while the face value price gap is €20,000. Lower notary fees partly offset the higher purchase price of the new-build.

In buy-or-rent.net, using the montant_fn field lets you see how this translates into monthly payments, total interest, and the comparison against a rental + investment strategy.

How notary fees affect the buy or rent decision

Notary fees are a non-recoverable entry cost. If you sell quickly, you never “get them back”, unlike the principal you repaid on the mortgage.

Short holding period: fees are a heavy drag

Example 3: buying existing, selling after 5 years

• Purchase price: €200,000
• Notary fees at 7.5 %: €15,000 (montant_fn)
• Initial renovation: €10,000
• Total entry cost: €225,000 (before interest)

If the property market is flat and you resell for €200,000 after 5 years, you have effectively “lost” the €15,000 notary fees + €10,000 works = €25,000. If instead you had rented, you would have paid rent but kept your capital, potentially invested at an investment rate (e.g. 3–4 % over the long term in diversified ETFs, with risk).

When you run this scenario in the simulator, the montant_fn parameter helps identify after how many years owning starts to outperform renting.

Long holding period: fees get diluted

Over 20–25 years, notary fees become less decisive:

• On existing property, €15,000 spread over 25 years is €600 per year (before interest).
• On new-build, €5,000 over 25 years is €200 per year.

They must be compared to:

• Annual inflation, which erodes the real value of these euros.
• Annual rent increases (linked to local indices), which make renting more expensive over time.

Notary fees remain a real cost, but the longer you stay, the less they dominate the buy or rent decision. The simulator, combining montant_fn, inflation and rent indexation, shows this dilution effect clearly.

New vs existing: you need a full cost picture

Focusing only on the notary fees would be misleading. Several other simulator parameters are crucial to a realistic buy or rent comparison.

Property tax and its revaluation

Property tax can range from about €450 to more than €5,000 per year depending on the city, and it is subject to annual revaluation. Some new-build programs offer temporary partial or full exemptions (often 2 years), partially compensating the higher purchase price.

In the simulator this cost is separate from montant_fn, but together they drive the true cost of ownership vs renting.

Renovation costs and energy performance

Existing homes often require a renovation budget:

• Cosmetic: paint, flooring.
• Compliance: electrical, plumbing.
• Energy retrofit (poor energy rating): insulation, windows, heating system.

New-build properties under recent standards typically mean lower energy bills and fewer major repairs in the first 10–15 years. The extra purchase price + lower notary fees must be weighed against these future savings.

Loan insurance and prepayment penalties

The borrower insurance rate (often 0.25–0.45 %) and possible prepayment penalties (capped around 3 % of remaining principal or 6 months’ interest) also shape the true cost of buying. They don’t change montant_fn, but they do change the global comparison with renting and investing.

Integrating notary fees into an investment strategy

From an investor’s perspective, notary fees are a significant friction cost compared with other assets. If you choose to rent and invest instead of buying, you:

• Avoid paying 7–8 % in notary fees on an existing property.
• Can invest this capital at your chosen investment rate (savings, bonds, ETFs).

Example 4: renting and investing the equivalent of notary fees

• Avoided notary fees (existing, €250,000 at 7.5 %): €18,750.
• Invested at 4 % per year over 20 years (hypothetical, with risk).
• Approximate final value: about €41,000.

On the ownership side, the buyer:

• Pays the €18,750 fees + interest.
• Builds equity in the property’s value (minus selling costs, property tax, maintenance, and renovation).

The core buy or rent question becomes: is the equity you build in the property, after accounting for notary fees (montant_fn) and other ownership costs, better or worse than the financial wealth you could build by renting and investing? The simulator is designed precisely to quantify that trade-off.

How to set montant_fn correctly in the simulator

To make your buy or rent simulation realistic, you must enter a good estimate of montant_fn:

• Existing property: typically 7–8 % of the purchase price (including any buyer-paid agency fees).
• New-build: typically 2–3 % of the sale price.

Practical steps:

• Ask the notary or agent for a written estimate of notary fees.
• Check whether agency fees are included in the listing price and who pays them.
• Enter the total amount (rounded) into the montant_fn field of the simulator.

Then adjust:

• Loan rate (around 3.6 % currently).
• Borrower insurance rate.
• Annual inflation.
• Annual rent increase.
• Property tax and its annual revaluation.
• Planned renovation budget.

This gives you a data-driven comparison between buying (new vs existing) and renting + investing.

Conclusion: notary fees are small on paper, big in impact

The difference between notary fees on new vs existing can easily reach tens of thousands of euros over the full life of your project. It is a key driver in your buy or rent decision, especially if your holding period is short or uncertain.

There is no one-size-fits-all answer: it depends on your location, the properties you compare, your time horizon, and your investment assumptions. This article is for information only and does not constitute personalised financial advice.

To see how notary fees (the montant_fn parameter) affect your numbers, with your rent, your loan rate and your investment options, the most efficient approach is to test several scenarios.

Simulate your situation on buy-or-rent.net