> For the complete documentation index, see [llms.txt](https://help.immodio.app/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.immodio.app/en/anleitung/mietverhaltnisse/mietverhaltnis-anlegen/mietanpassung/vergleichsmiete.md). # Comparative rent This page explains how a rent adjustment to the local comparative rent works and which statutory conditions have to be observed.
If neither a graduated nor an index-linked rent agreement is made, the rent can be adjusted to the local comparative rent under Section 558 BGB. The following aspects have to be observed: ### Deadlines Under Section 558 BGB, as a landlord you may only demand a rent increase in line with the **local comparative rent** if you observe the statutory deadlines. Under Section 558 (1) BGB, a rent increase may take effect at the earliest **15 months after the last rent increase** (or the start of the rental agreement in the case of a new letting). A written request for a rent increase is required in order to raise the rent. You may only make this request once the rent has remained unchanged for **at least twelve months** since the last rent increase (the one-year blocking period). If the tenant receives the request before the one-year blocking period expires, it is invalid. Rent increases due to modernisation (Section 559 BGB) or adjustments to operating costs (Section 560 BGB) do not affect this blocking period. Once the request for a rent increase has been received, the tenant has a statutory period for consideration until the end of the second calendar month after receipt. The increased rent is then only due from the beginning of the third month after receipt of the request. Together, the blocking period and the period for consideration mean that the increased rent is owed at the earliest **15 months after the last change in rent**.
Example The rent was last increased on **1 May 2026**. The one-year blocking period therefore begins on **1 May 2026**. A new request for a rent increase may therefore reach the tenant **at the earliest on 1 May 2027**. If the request arrives on **1 May 2027**, the tenant's statutory period for consideration ends at the end of **30 June 2027**. If the tenant agrees, the increased rent is payable **from 1 July 2027**.
### Capping limit The **capping limit** (Section 558 (3) BGB) is a statutory rule limiting rent increases. The rent may not rise by more than **20%** within three years. In areas with a strained housing market this limit can be reduced to **15%** by statutory instrument. ### Obligation to give reasons The landlord has to justify the rent increase in text form. This can be done by reference to: * **A rent index:** reference to a simple or qualified rent index (Sections 558c, 558d BGB). Justification by means of the rent index is the normal case in larger cities. Since July 2022, all towns and municipalities with more than 50,000 inhabitants have been legally obliged to produce a rent index as part of the rent index reform. * **A rent database:** information from a rent database maintained by the municipality or by private institutions (Section 558e BGB). * **An expert opinion:** an opinion from a publicly appointed and sworn expert. * **Comparable apartments:** naming three apartments comparable in terms of size, location, fittings and condition. ### The tenant's consent For an increase to take effect, the tenant's consent is required. This consent can be given or refused up to the end of the second month after the request for a rent increase is received. The tenant does not have to consent to a rent increase automatically, however; they may first check whether the request is formally correct and justified in substance. Without the tenant's consent the increase does not take effect by itself; the landlord may have to enforce it through the courts (Section 558b BGB). {% hint style="info" %} Immodio supports you in preparing a rent increase in line with the local comparative rent. Under [Templates](/en/anleitung/vorlagen.md) in Immodio you will find a suitable letter to your tenants. {% endhint %} ### Further legal notes
Rent increase after modernisation A rent increase due to modernisation is possible under **Section 559 BGB** where the measures increase the value of the accommodation, save energy sustainably or improve living conditions. In that case the landlord can pass on 8% of the modernisation costs attributable to the apartment to the rent each year. **Conditions for the rent increase:** 1. **Obligation to announce:**\ The landlord has to announce the modernisation measures in writing at least three months before they begin (Section 555c BGB). This announcement has to state the nature, extent and expected duration of the measures as well as the expected rent increase. 2. **Calculating the costs:**\ The costs allocated to the apartment have to be proportionate to the property as a whole. The share of repair and maintenance costs has to be deducted from the recoverable modernisation costs. The same applies to public grants, subsidies and interest concessions. There is one exception to this rule: if the modernisation costs per residential unit are no more than 10,000 euros, the landlord can deduct a flat rate of 30% of the costs without having to prove the exact split between modernisation and maintenance costs. 3. **Upper limit for the rent increase:**\ The rent may rise by a maximum of 3 euros per square metre if the starting rent is above 7 euros per square metre; if the starting rent is less than 7 euros per square metre, the increase is limited to 2 euros per square metre. **Examples of recoverable measures:** * Installing a new heating system or thermal insulation of the facade. * Replacing windows or doors to improve energy efficiency. * Adding a balcony or installing a lift.
Advantages of the comparative rent * **Reflects market developments:** The rent reflects the respective rental market. * **Individual adjustment:** No fixed tie to previously agreed stages or the consumer price index. * **Passing on modernisation measures is possible:** Additional increases due to modernisation (Section 559 BGB) can be claimed. * **Reference to rent control:** The increase remains tied to the local comparative rent, which offers legal certainty.
Disadvantages of the comparative rent * **Justification is laborious:** It requires a rent index, an extract from a rent database, three comparable apartments or an expert opinion. * **The tenant's consent:** The tenant has to consent actively to the rent increase, which can cause conflict. With graduated and index-linked rental agreements this consent is not necessary. * **Capping limit:** The increase is limited to a maximum of 20% (or 15% in regions with a strained housing market) within three years (Section 558 (3) BGB). * **Regular administrative effort:** Every increase has to be justified and enforced again. It does not happen automatically, as it does with a graduated rent.