When I read a regulation that says “maximum 90 nights a year,” my mind does two things.
The owner part thinks:
“Okay. Another thing to control.”
The financial part asks a much less legal question:
“If I can only sell 90 nights, how much does each one need to bring in for the numbers to still work?”
Because a regulation can take up two lines.
But those two lines can completely change a business.
So we conducted an experiment.
We took the same theoretical property, the same annual economic goal, and the same percentage of nights sold.
We only changed one thing: the maximum number of nights allowed by a specific legal route.
In our scenario, going from a capacity of 180 nights to one of 15 means that each sold night has to produce 12 times more to reach exactly the same annual goal.
The property hasn’t changed. The bed hasn’t either. What has changed is the number of nights over which you can spread the result.
The House We Will Move Around the World
We will call it Gatavia House 01.
It does not exist.
And that’s exactly why it works for us.
If we used a real property in Paris and another different one in Tokyo, the purchase price, cleaning, taxes, demand, energy, size, guest, and almost everything else would change at the same time.
Then it would be very difficult to know what we are measuring.
We want to isolate a single variable:
What does the number of legally available nights do to the economy of a property?
Annual contribution goal: €24,000
Percentage of legal nights we manage to sell: 80%
Same property, same costs, and same economic goal in all scenarios.
We are not saying that €24,000 is a normal or recommended profitability. It is a laboratory figure we use to check what happens when we only change the legal capacity for operation.
First, a Word That Sounds More Complicated Than It Is
We are going to talk about contribution.
It is not revenue.
And it is not automatically the final profit.
Simply put: it is the money we need the sold nights to contribute to help pay the business costs and reach the result we have set.
If we want to achieve €24,000 a year and can spread it over 144 sold nights, each night has to carry a part.
If we can only spread it over 12 nights, that part becomes huge.
Now We Move the House
First, an important clarification.
We are not saying that “Airbnb only allows X nights” in each of these cities.
We are comparing specific regulatory routes.
The same city may allow other accommodation models, professional licenses, changes of use, or different regimes.
That detail matters a lot.
In Paris, a primary residence can be rented as furnished tourist accommodation for a maximum of 90 days a year.
A property that is not a primary residence falls under a different regime and requires, among other requirements, certain authorizations and formalities. Therefore, the 90 days of our experiment correspond specifically to the primary residence route.
In London, a residential property can be used for short-term rental for a maximum of 90 nights per calendar year without obtaining the necessary planning permission to exceed that limit, provided that the applicable conditions are met.
Exceeding those 90 nights changes the situation from an urban planning perspective and requires a review of the corresponding regime.
In Amsterdam, the vacation rental regime for one’s own home generally allows a maximum of 30 nights per calendar year.
From April 1, 2026, certain neighborhoods in Centrum and De Pijp have a maximum of 15 annual nights.
Additionally, there are requirements for permits, registration, communication of stays, and other conditions. Here we are isolating only the annual night limit.
The route regulated by the Private Lodging Business Act, commonly known as minpaku, establishes a national maximum of 180 days of accommodation per year.
This maximum can be reduced by local ordinances. Japan also has other accommodation regimes. Therefore, we are comparing the minpaku route, not claiming that all tourist accommodation in Japan is limited to 180 days.
Now Comes the Math
And it is much simpler than all the previous regulations.
We just have to divide.
| Regulatory Scenario | Maximum Used | We Sell 80% | Annual Goal | Needed Per Sold Night | Load vs 180 Nights |
|---|---|---|---|---|---|
| Japan · National Minpaku Route | 180 nights | 144 nights | €24,000 | ≈€167 | 1× |
| Paris · Primary Residence | 90 days | 72 nights | €24,000 | ≈€333 | 2× |
| London · Analyzed Route | 90 nights | 72 nights | €24,000 | ≈€333 | 2× |
| Amsterdam · General Regime Analyzed | 30 nights | 24 nights | €24,000 | €1,000 | 6× |
| Amsterdam · Certain Areas of Centrum / De Pijp | 15 nights | 12 nights | €24,000 | €2,000 | 12× |
With the same annual goal and selling the same 80% of the available capacity, going from 180 to 15 nights multiplies by 12 the contribution that each sold night must provide.
You don’t need to know finance to understand it.
If you have to achieve €24,000 spread over 144 nights, each one carries about €167.
If you have to achieve exactly those same €24,000 with only 12 nights:
each one has to carry €2,000.
The house remains the same.
The goal remains the same.
The only thing that has changed is how many opportunities you have to achieve it.
And Here Comes a Measure We Want to Follow
Gatavia Regulatory Night Burden
The technical name may sound great.
But what we want to measure is quite simple:
how much economic result each night you can sell has to bear when a regulation reduces your annual capacity.
It does not attempt to say whether a regulation is good or bad. It tries to measure a specific economic consequence.
But Be Careful: This Does NOT Mean That Amsterdam Is Twelve Times Worse Than Japan
No.
And if we said that, we would be doing precisely the type of analysis we do not want to do at Gatavia.
To compare real profitability between cities, we would need to introduce many more factors:
Real ADR, occupancy, season, length of stay, and ability to sell available nights.
Purchase, acquisition taxes, renovation, furnishings, and financing.
Cleaning, laundry, supplies, maintenance, insurance, software, and management.
License, primary residence, permitted use, ordinances, community or building, and regulatory alternatives.
Today we have not compared all that.
Today we have done something smaller and, precisely for that reason, cleaner: change a single variable and see what it causes.
That way we know exactly where the result comes from.
Regulation Does Not Just Take Away Nights. It Changes the Numbers
This is the part that interests me most as an owner.
When I read:
“The city limits tourist rentals to 90 nights.”
I no longer want to just stay with the legal data.
I want to know:
“What just happened to what I need to obtain from each night for the property to still make sense?”
In our example:
| If You Go From... | To... | To Maintain the Same Goal, the Load Per Night... |
|---|---|---|
| 180 Nights | 90 Nights | doubles |
| 180 Nights | 30 Nights | multiplies by 6 |
| 180 Nights | 15 Nights | multiplies by 12 |
| 30 Nights | 15 Nights | doubles |
This does not automatically mean you have to multiply your rate by those numbers.
Perhaps the annual goal is no longer reasonable.
Perhaps there is another legal route.
Perhaps you have to combine models.
Perhaps it makes sense to use half-stays during another part of the year.
Or perhaps that property no longer makes sense under that model.
And reaching that conclusion is also doing the math right.
This Is Where Observatory and Radar Stop Looking Alike
If tomorrow a city goes from 30 to 15 nights, Radar has to alert you.
As soon as possible.
Because you need to know what has changed.
But the Observatory starts right after that.
Question:
“Okay. What has that change done to the economy of the property?”
Radar detects.
The Observatory measures.
Do the Math with Any Night Limit
Gatavia Calculator · Regulatory Night Burden
Change our numbers for yours.
This is not a profitability forecast. The tool isolates only the mathematical effect of the number of available nights. It does not incorporate demand, ADR, purchase price, taxation, financing, or local costs.
What Would We Do with This Information?
We would not buy a property based solely on this calculation.
Not by a long shot.
But we also wouldn’t read a night limit as just a legal data point.
Before buying, changing models, or assuming a new regulation, we would at least do these three calculations:
How many nights can I really sell under my legal route?
How much does each night need to leave for the business to work?
Is there enough demand to sell those nights at the economic level I need?
If the third answer is no, the problem is not solved by wishing for a higher ADR.
A night regulation does not just limit the calendar. It spreads your business over fewer sales opportunities.
In our experiment, with the same economic goal and the same 80% utilization:
180 nights → approximately €167 per sold night.
90 nights → approximately €333.
30 nights → €1,000.
15 nights → €2,000.
If the market cannot support what you need to obtain per night, you do not have a pricing problem. You have a business model problem.
Why This Is Not Another Ranking of “Best Cities for Airbnb”
Because we still don’t know which is better.
And we don’t intend to make it up.
A city with a lower night limit may have much higher prices, lower costs, cheaper housing, or a completely different professional route.
Another with 180 theoretical nights may have additional local restrictions or insufficient demand.
The Observatory does not exist to create winners. It exists to understand which variable is really moving the result.
What Comes Next
This is just the first layer.
Now we can add, research by research:
acquisition price, ADR, occupancy, taxation, labor cost, energy, management, maintenance, financing, and stress tests.
And then we can ask much better questions than:
“Which city generates the most revenue?”
We can ask:
“In which city does a property owner really buy a better business?”
That’s where we want to take the Gatavia Global Observatory.
Quick Questions
Does Paris have a general limit of 90 nights for any tourist property?
No. The 90 days correspond to the primary residence within the analyzed regime. Properties that are not primary residences are subject to other rules and authorizations.
Can you never exceed 90 nights in London?
The analyzed rule allows up to 90 nights of short-term rental of a residential property without the necessary planning permission to exceed that use. Exceeding it requires a review of another regulatory situation.
Does Amsterdam limit all tourist rentals to 15 nights?
No. In the analyzed regime, the general rule is 30 nights. From April 1, 2026, certain neighborhoods in Centrum and De Pijp have a maximum of 15 nights. There are also other types of accommodation and regimes.
Does all tourist accommodation in Japan have a maximum of 180 days?
No. The 180 days correspond to the regime regulated by the Private Lodging Business Act or minpaku. There are other systems, and local ordinances may introduce additional restrictions.
Are €167, €333, €1,000, and €2,000 recommended prices?
No. They are mathematical results from the Gatavia experiment using a fictitious annual goal of €24,000 and an 80% utilization of the permitted nights. They do not represent market ADR or a revenue forecast.
Gatavia Methodology
Question: How does the necessary economic result per night change when we only reduce the number of legally available nights?
Modified Variable: Annual maximum nights of the analyzed regulatory route.
Maintained Variables: Property, annual economic goal, and utilization percentage.
Goal Used: €24,000 annual contribution.
Utilization: 80% of the maximum available nights.
Formula: Annual goal ÷ (maximum nights × utilization).
Limitation: This experiment does not calculate real estate profitability or compare actual performance between cities. It isolates exclusively the arithmetic effect of the available annual capacity under the selected regimes.
Date of Regulatory Verification: August 31, 2026.
Primary Sources
Ville de Paris: Furnished Vacation Rentals: Rules to Follow .
London City Hall: Guidance on short term and holiday lets in London .
City of Amsterdam: Holiday rental permit and rules .
City of Amsterdam: Holiday rentals in parts of Centrum and De Pijp .
Japan Tourism Agency / MLIT: Private Lodging Business Act .