Imputed rental value calculator: what changes in 2029?

The calculator above follows today’s formula for your tax return. First comes your imputed rental value (Eigenmietwert). This is the amount you declare as income because you live in your own home, rather than letting it out. From this, the calculator subtracts your mortgage interest, and then your maintenance costs.

For maintenance, you have a choice today. The flat allowance is a fixed percentage, used instead of itemised receipts. In Canton Zurich, it is 20 per cent of your imputed rental value. This applies whatever the age of your house.² Or you use your actual, itemised costs, if these are higher.¹ You may choose afresh each year.

What remains is your balance. You pay tax on this balance, at your marginal tax rate.¹ This is the rate on your last taxable franc. What this means for you: the higher your maintenance and interest costs, the smaller your balance. And the less tax you pay on it today. That is what the calculator works out, from your own three figures.

For the calculator above, you need your own figure, not a stranger’s example. You find your imputed rental value in your latest tax return, under cantonal and communal tax. Some municipalities also show it in their own assessment decision (Einschätzungsentscheid), an official letter setting the value of your house.

If no separate figure appears there, your tax assessment notice (Veranlagungsverfügung), the yearly statement from your tax office after filing, shows it instead. If you took over the house only recently, for example through inheritance, ask your municipal tax office for the current figure. Do not estimate it yourself.

What this means for you: use the figure from your own assessment, not an average figure from the internet. Only then does the calculator above show a figure that truly fits your house, not just a typical house in your municipality.

Your marginal tax rate (Grenzsteuersatz) is the rate on your last taxable franc, not your average rate across your whole income. It appears nowhere as its own figure on your tax return. That is exactly why the calculator above asks you to enter it yourself, rather than estimating it on its own.

There is no single figure for every owner in Canton Zurich. Your marginal tax rate depends on your total taxable income, on your home municipality and on your marital status. Your latest tax bill, or your tax office, shows the true figure for your own case.

What this means for you: start with a rough estimate, using your latest tax bill as a guide. For a binding figure, ask your tax office or your accountant (Treuhänderin), before building a decision on this calculation alone.

No official source gives one answer for every owner.⁵ How the reform affects you depends on three figures: your imputed rental value, your mortgage interest, and your marginal tax rate. The calculator above uses your own three figures, not an average.

The Federal Tax Administration names a tendency. Those who have largely paid off their mortgage are more likely to gain, at low interest rates. The authority says this is typically true for retirees.⁵ A large mortgage changes the picture. The deductions you lose, for maintenance and interest, then outweigh the imputed rental value you also lose.

For your own figures, there is a tipping point. It is the mortgage rate at which today’s balance sits at zero. Below it, the reform tends to help you. Above it, the reform tends to cost you. The second worked example below shows this point for a high-mortgage case.

What this means for you: enter your own three figures above. Do this before relying on a general claim about winners or losers.

This calculator leaves out five things, on purpose. First, the first-time buyer deduction (Ersterwerberabzug), for children buying their own home for the first time. This time-limited deduction for mortgage interest is explained on imputed rental value: what is changing?.

Second, a let flat or a second home. The maintenance deduction continues there, even after 2029.⁴ The calculator above only covers your own home. Third, federal and cantonal practice differ on today’s allowance. The federal rate depends on the age of your house: 10 per cent up to 10 years, otherwise 20 per cent.³ Canton Zurich applies a flat 20 per cent instead.² The calculator folds this into one simple figure.

Fourth, wealth tax on your house continues, regardless of the imputed rental value, as explained on imputed rental value: what is changing?. Fifth, the calculator gives no forecast for the property market or for future mortgage rates. What this means for you: use the figure as a starting point, not as a final answer for your tax return.