Rent increases are a source of conflict. The landlord wants an appropriate rent for their property, while the tenant wants to pay as little as possible. If the rent originally agreed is to increase after a few years, this can lead to a dispute. This can be avoided through index-linked rent. It is fixed contractually and helps prevent disagreements. This form of rent pricing has advantages and disadvantages and is subject to special rules.
What is index-linked rent?
Most tenancy agreements include a fixed net cold rent. The landlord must announce every rent increase, and the tenant must agree to it. With index-linked rent, things are different. Both parties already stipulate in the tenancy agreement that the rent will regularly be adjusted in future to reflect changes in the cost of living.
For such agreements, the landlord may increase the rent regularly, but each increase may be made no earlier than after at least twelve months. The landlord must announce this increase in writing and state the new rent amount (or the surcharge).
The basis is the inflation rate
The amount of the adjustment is defined. This means that the landlord may not use an arbitrary price. They must base it on the inflation rate. More precisely: Rent changes are based on the change in the consumer price index. The Federal Statistical Office calculates this using a basket-of-goods system. It contains a large number of products and typical living expenses.
Every few years, the Federal Statistical Office resets the consumer price index to a base value of 100. In the following years, the rate of price increase is added to this base value as a surcharge. If the price index rises by six points from the base year, this results in a new consumer price index of 106. The permissible increase in index-linked rent can be determined from this change in the index.
Index-linked rent: Calculating the rent increase
Since the changes are added to the base value year after year, the landlord must calculate the applicable percentage increase. Only then can they determine the actual rent increase. A formula is available for this purpose. It is:
(New index value ÷ old index value) × 100 – 100 = percentage increase
An example illustrates how this is applied. If the initial value for a consumer price index is 110, The previous year and the current year’s figure of 113 are divided. This results in an interim sum of (113/110 =) 1.02727. This amount is multiplied by 100, resulting in 102.727. Subtracting 100 leaves 2.727 as the percentage increase.
This percentage increase forms the basis for the rent increase. The landlord multiplies the previous rent by this factor and thus determines the increase. With a net cold rent of 750 euros per month, the example calculation results in an increase of 20.45 euros to 770.45 euros (750 euros x 2.727/100).
Important: Since the Federal Statistical Office adjusts the base values every few years, the correct calculation can be tricky, particularly for long-running index-linked rental agreements. For such cases, the authority provides a so-called value preservation calculator.
Legal basis and special features of index-linked rent
The exact details of index-linked rent are set out in Section 557b of the German Civil Code (BGB). Such an agreement therefore complies with the law. However, there are several special features that result from this for both tenants and landlords.
- The index-linked rent must be explicitly agreed in the rental contract.
- At least twelve months must pass between two increases.
- The landlord may not adjust the rent for other reasons (e.g. based on the local comparative rent).
- The landlord may not demand an increase following modernization measures; exceptions are measures for which the landlord is not responsible (for example, due to statutory requirements).
- The rent adjustment must be made in text form, with reference to the exact change in the consumer price index and the specific change in the net cold rent.
- The new rent is not valid until the calendar month after next following receipt of the information.
- Unlike standard contracts, the tenant’s consent to the adjustment is not required.
Important: These rules apply to the net cold rent specified in the contract. If it is a so-called gross cold rent, this too falls under Section 557b BGB.
Index-linked rent: advantages and disadvantages for landlords
For landlords, an agreement on index-linked rent offers a major advantage: The net cold rent can be regularly adjusted in line with consumer price developments without requiring the tenant’s consent. This creates Provides planning certainty, prevents conflicts, and offsets inflation losses. In addition, such an agreement allows rent to increase even when the statutory rent cap actually applies.
Landlords particularly benefit from linking rent to consumer price developments when the cost of living rises more sharply than the local comparative rent. However, if local comparative rents rise more sharply, the landlord is at a disadvantage.
Another disadvantage is the exclusion of adjustments following modernizations. If the property owner improves the standard of the building or apartments, they cannot pass these improvements on to the rent. The only exception is modernization measures required by law. These may be added to the rent in the permitted amount even outside the twelve-month periods.
The effort involved should not be underestimated. The landlord must remember in good time to increase the net rent and calculate the permitted increase each time. The waiting period of a further two months after notification must also be taken into account.
Index-linked rent: advantages and disadvantages for tenants
Tenants benefit from index-linked rent through generally moderate adjustments, which are based exclusively on consumer price developments. The inflation rate is usually around a percentage rate of approximately two percent. A net rent of 800 euros per month therefore increases by around 16 euros when adjusted. Compared with rent increases under other contracts, this increase may be relatively small. Tenants therefore benefit particularly in areas with rapidly rising rents.
This advantage also has a disadvantage: It is difficult to estimate exactly how high the rent will be next year. Especially in times of crisis with rising inflation, an index-linked rent actively used by the landlord can be a financial disadvantage.
The same applies to adjustments made retrospectively. For example, a landlord is permitted to adjust the rent only after several years. As a result, the increase may be above average.
However, if the consumer price index falls (deflation), tenants can in turn press for a reduction in the net rent. The calculation works analogously to an increase, except that the net rent is reduced.
Distinction from stepped rent
Index-linked rent should not be confused with stepped rent. With the latter, after a provision in the rental agreement an automatic rent adjustment after a predetermined period. This is agreed by both parties independently of other influencing factors. As a rule, fixed increases in the basic rent are agreed after a certain number of years.