It’s done, and it’s dated. The people and the cantons accepted the reform on 28 September 2025; the Federal Council has set its entry into force at 1st January 2029. The decision is constitutional: no appeal or referendum can overturn it now. What remains is the real question for a property owner — what changes, and what is worth deciding before then.
The decision, and why 2029
Adopted by the Federal Chambers in December 2024, the reform passed the mandatory referendum on 28 September 2025. On 1st April 2026, the Federal Council set the date: 1st January 2029.
This delay is not administrative slowness. The tax harmonisation law requires cantons to have at least two years to adapt their legislation, and the cantonal finance directors expressly requested 2029 — time to introduce, should they wish, the special tax on secondary residences that offsets their loss of revenue.
What imputed rental value was
A notional income: the rent you would receive if you let out the home you occupy, set in practice at between 60 and 70% of market rent, and taxed as ordinary income. In return, you could deduct mortgage interest and maintenance costs. The reform abolishes both sides of this mechanism.
What changes on 1st January 2029
| Element | Until end of 2028 | From 2029 |
|---|---|---|
| Imputed rental value | Taxed as notional income | Abolished |
| Maintenance costs | Deductible each year | No longer deductible (own residence) |
| Mortgage interest | Fully deductible | Deductible pro rata for let properties only |
| Energy-saving works | Deductible from federal tax | No longer deductible at federal level; cantonal option possible |
| Secondary residence | Imputed rental value taxed | Abolished; special cantonal tax possible |
| Let property | Rents taxed, costs deductible | Unchanged regime |
Two nuances matter. First-time buyers will retain a temporary, capped interest deduction for the first years. And landlord owners are not affected: a let property continues to be taxed on its actual rents, with deductible costs.
The first-time buyer deduction, in francs
The reform makes allowance for those buying their first home in Switzerland: for ten years, they retain a deduction for passive interest, capped at 10,000 francs for a married couple and 5,000 francs for other taxpayers.
In Geneva, this cap is worth comparing against local prices. Take a first purchase at 1.2 million financed at 80%: 960,000 francs of debt. At an illustrative rate of 2%, annual interest approaches 19,000 francs — the 10,000 cap therefore covers roughly half of it. The figure is not a forecast, it is an order of magnitude: adjust it to your actual rate with the mortgage simulator. But the lesson holds: in a market where the entry ticket exceeds one million, the cushion provided by the federal legislator absorbs only part of the shock.
What the reform does not touch: the supplementary property tax
A Geneva property owner pays a tax that the reform leaves entirely intact, and which is often overlooked in these discussions: the supplementary property tax (impôt immobilier complémentaire). It is a tax on the property itself — it applies to the asset, not to your ability to pay. Its rate is 1‰ of the tax value, reduced to 0.2‰ when the property is your main residence. It is owed by the person registered in the land registry as owner or usufructuary as at 31 December.
One detail changes everything in the debate about paying down debt: it is calculated on the tax value without deducting debts. Repaying your mortgage therefore does nothing to reduce it — unlike the wealth tax. Two taxes, two opposing logics applied to the same debt.
And an exit route few owners know about: a building meeting high or very high energy standards — HPE and THPE — can obtain, upon request, a twenty-year exemption from this tax. “Upon request” is the key phrase: it does not apply automatically. If you are buying in a new-build development in Geneva, the question is worth raising before signing, not three years later.
Who gains, who loses
The gain is clear-cut for owners with little or no debt — typically retirees who have paid off their mortgage: the imputed rental value disappears from their taxable income without them losing any significant deductions.
The balance tightens for heavily mortgaged owners: the interest deduction disappears at the same time as the imputed rental value. The higher your debt relative to the property’s value, the more the advantage shrinks.
What to decide before 2029
Maintenance works
Maintenance costs remain deductible until the end of 2028. Works you were planning to carry out anyway — roof, façade, kitchen — have more tax value if completed before the deadline than after. 2027 and 2028 are likely to see companies’ order books lengthen: planning ahead also means booking ahead.
Paying down the mortgage
From 2029, keeping high debt on your main residence will no longer bring any tax benefit. The question of “pay down or invest” will resurface for many households — it depends on your rate, your tax situation and your pension planning, and deserves calculated advice rather than a general rule.
Secondary residences
The imputed rental value disappears there too, but each canton may create a special tax to compensate. If you own a chalet or a pied-à-terre, the canton where it is located will determine your actual situation — cantonal decisions will be made between now and 2029.
And for the Geneva market?
In Geneva, where prices make debt structurally high, the reform reshuffles the deck between buyer profiles: it favours substantial own funds and rapid debt repayment. For a Left Bank owner, it mainly changes the long-term holding calculation — what the property is worth remains the primary question, and it is measured against actual transactions in your commune.
If the reform prompts you to consider a sale or a reassessment, start with a valuation based on registered sales, and our page on selling with Rousseau 5 describes the method. The tax terms used in this article are defined in the property glossary.