If your tenancy agreement states that the rent is "value‑protected" (wertgesichert), it may rise with inflation. Since 1 January 2026 the Mieten‑Wertsicherungsgesetz (MieWeG) limits when and by how much this may happen for most rental flats – including older contracts. Here you will learn how the new calculation works and what additionally applies in older buildings.
No index increase without a clause
A value‑protection clause does not arise automatically. It must be agreed in the contract; if it is missing, there is usually no inflation‑related increase of the basic rent [S8]. If a clause is present, for contracts with commercial landlords it must among other things be comprehensible and, where appropriate, also provide for a reduction [S5]. Whether your clause is effective can only be assessed by the exact wording.
For which flats the new cap applies
The MieWeG covers main and sub‑tenancy agreements for flats within the scope of the MRG – that is in the full‑application area (typical: old buildings) and in the partial‑application area (typical: privately financed new build, rented condominium in a post‑war building) [S1][S7]. Flats that are entirely excluded from the MRG are not covered, for example in houses with at most two independent flats [S1][S7]. The cap generally does not apply to cooperative flats under the Wohnungsgemeinnützigkeitsgesetz either [S1].
The new calculation model in three steps
- Date: The rent is increased or decreased once a year, on 1 April – at the earliest in the first full calendar year after the contract was signed [S1]. If your contract specifies a different month, the increase is postponed to the next 1 April, and only to the extent that would have been permissible at the contractual date [S1].
- Reference: The relevant measure is the average change of the consumer price index in the previous year, calculated from the annual average values [S1].
- Cap: Inflation up to 3% is passed on in full. Anything above that counts only half [S1].
Hypothetical example: If inflation in a year is 6%, the rent may increase by at most 4,5% in the following April (3% plus half of the remaining 3%).
For the first adjustment after contract conclusion only the portion of the previous year’s inflation that falls on the full months after contract conclusion is counted [S1].
Hypothetical example: You sign on 10 March 2026 a contract for a new‑build flat with a basic rent of EUR 800. Full months thereafter are April to December, i.e. nine. If inflation in 2026 is 4%, the cap amounts to 3,5%; of that 9/12, i.e. 2,625%, counts. From 1 April 2027 the rent may increase at most to EUR 821. Whoever signs in December has no full month in the first year and therefore earliest a rise in the April of the following year.
These limits also apply if the contract contains a fixed increase by an amount or percentage – unless the increase has a reason other than the value‑protection clause [S1].
Old buildings and other flats with a rent ceiling: 1% and 2%
Where the MRG limits the rent level, i.e. primarily for Richtwert, Kategorie and angemessener Mietzins in the full‑application area, the increase is capped even more strictly: the inflation of the year 2025 may be set at at most 1%, that of the year 2026 at at most 2% [S1]. In parallel the statutory guideline values (Richtwerte) may also rise by at most 1% on 1 April 2026 and by at most 2% on 1 April 2027; from 2028 the halving of the share above 3% applies here as well [S3]. The same sequence applies to the category amounts (Kategoriebeträge) [S2][S11].
In addition, in the full‑application area: the landlord must demand the increase in writing after it becomes effective, at least 14 days before the payment date from which the higher rent is to be paid [S2]. The AK Wien derives from this that an increase in this area can become effective at the earliest in May [S9]. Furthermore the value‑protected rent may never exceed the statutory ceiling; any exceeding part is ineffective [S2].
Hypothetical example: The rent of an old‑building flat with a EUR 600 Richtwert rent was last adjusted based on the index value for December 2024. Then the value‑protection could in spring 2026 bring at most EUR 6 more.
Transitional law: What applies to contracts before 2026
The MieWeG also applies to contracts concluded before 1 January 2026, and specifically to increases that take effect or would have taken effect from that day [S4]. If the rent has already been adjusted once, the starting point is the month to which the index value of the last adjustment referred; in this case exceptionally more than just the previous year may be taken into account [S4].
Hypothetical example: Your 2023 contract provides for adjustments each August. The increase calculated for August 2026 then only takes effect on 1 April 2027 – and only to the permissible extent.
2025, reclaim and further clarifications
Already in 2025 the legislator cancelled the increase of the Richtwerte and Kategoriebeträge scheduled for 1 April 2025 [S6]. Since 1 January 2026 it also applies that the two‑month rule of the Konsumentenschutzgesetz for price increases shortly after contract conclusion does not apply to continuing obligations such as longer‑term tenancy agreements [S5]. For clauses that link to an index value from before contract conclusion the ABGB now provides criteria for assessment [S10].
Excess amounts paid due to ineffective clauses in old contracts can only be reclaimed to a limited extent – generally for five years, with exceptions for example in the case of abusive clauses [S4]. If in doubt have your contract checked by the Arbeiterkammer, a tenants’ organisation or – in Vienna – the Schlichtungsstelle.