The local reference rent: the figure behind every rent limit
Rent increases, the rent brake and housing benefits all depend on one figure: your flat’s local reference rent.
Checked by Radif Partners · Editorial policy · Method
Your rent next to the reference rent
Reference rent for your area
€617.50
| Your rent per m² | €11.08/m² |
| Gap to the reference rent | 16.6 % |
| Ceiling on a new lease (+10%) | €679.25 |
Under Section 558(2) of the German Civil Code, the local reference rent (ortsübliche Vergleichsmiete) is formed from the usual rents agreed or changed in the municipality over the last six years for housing of comparable type, size, fittings, condition and location, including energy features. Rents set by law or under a subsidy commitment are left out. So it is not the market price of a new flat but an average of new leases and existing rents. It is justified with a rent index (Mietspiegel), a rent database, an expert opinion or three comparable flats (Section 558a). Berlin's 2026 index shows how much fittings matter: a 1975 flat of 70 m² in an average location sits at the mean of €8.09 per square metre, at €8.97 with a better bathroom and kitchen, and at €7.23 with three weaker groups of features. In Dortmund the area alone makes a difference of €0.91 per square metre between Dortmund-West and Innenstadt-Mitte.
The five features in the law
Section 558(2) BGB names five features by which flats must be comparable. Type means the kind of building: apartment block, house, pre-war or post-war. Size is the floor area. Fittings cover everything the landlord provides: heating, bathroom, kitchen, flooring, balcony. Condition means age, state and layout of the flat, expressly including energy features. Location is the surroundings: traffic, noise, green space, infrastructure. Rent indexes translate these features into table fields, premiums or points.
One example, two systems
| Flat built 1975, 70 m² | Reference rent per m² | per month |
|---|---|---|
| Berlin, average location, mean | €8.09 | €566.30 |
| Berlin, average location, better bathroom and kitchen | €8.97 | €627.90 |
| Berlin, average location, three groups worse | €7.23 | €506.10 |
| Dortmund, Dortmund-West area, no premiums | €6.00 | €420.00 |
| Dortmund, Innenstadt-Mitte, no other premiums | €6.91 | €483.70 |
The Berlin figures show how much placement within the range matters: between weak and good fittings, the same flat differs by €121.80 a month. In Dortmund the location shifts the value because the index sets a fixed premium per area. Anyone working out the reference rent without a calculator usually underestimates these margins.
The four ways to justify it
For a rent increase, the landlord must justify the reference rent in his letter. Section 558a(2) BGB names four ways, without making the list exhaustive:
- Rent index. The usual route; if the rent demanded lies within the range, a reference to it is enough. More on the rent index explained page.
- Rent database. A continuously kept collection of rents run or recognised by the municipality or jointly by both sides (Section 558e BGB). Rare in practice.
- Expert opinion. A reasoned opinion by a publicly appointed and sworn expert. Expensive, but often the only route for flats outside an index.
- Three comparable flats. With address, position in the building, size and rent, so the tenant can check them.
If a qualified rent index contains figures for the flat, the landlord must state them even when relying on another method (Section 558a(3)). That way the tenant sees whether an expert opinion lies far above the official value.
What the reference rent decides for you
On a new lease in a rent-brake area it is the basis of the ceiling: for the 1975 Berlin flat, at most €622.93 is lawful; anyone paying €600 pays €0.00 too much. On a rent increase it is the upper limit: from €480 the rent may rise to at most €552.00 here, because the 15 per cent cap bites before the reference rent. The rent increase page explains the difference between the two limits. Since the area goes into every calculation, the floor area page is worth a look too.
Five mistakes that distort the reference rent
- Wrong year built. Rent indexes ask when the building or flat was completed, not when it was refurbished. A flat built in 1910 and modernised in 2015 remains a pre-war flat; the modernisation counts as a feature.
- Your own installations counted. What you installed and paid for yourself, such as a kitchen or new flooring, may not raise the reference rent. Only the fittings the landlord provides count.
- All-inclusive rent not converted. Rent indexes give net cold rents. If your rent includes a share for service charges, take it out before comparing, otherwise the rent looks too high.
- Location by gut feeling. The residential location follows from the city's directory for your address. A quiet side street can be rated basic, a noisy main road in a sought-after district good.
- Outdated index. An increase letter quoting a superseded edition is open to challenge if a current index exists. Check the date of the edition the landlord relies on.
When no rent index fits
Many indexes exclude certain homes: houses, very new buildings, very large or small flats, flats without a bathroom. Then the reference rent can only be justified with an expert opinion or comparable flats. Under Section 558a(4) an outdated index or that of a comparable municipality may also be used if no current one exists. In the rent check, enter the value you were given for such cases. If an increase letter gives no justification at all, it is formally invalid: the landlord must send a new, fully justified letter, and the deadlines only start again when it arrives.