Kaltmiete, Warmmiete and the Nebenkosten settlement

Two rents, one payment

German listings quote two numbers and newcomers routinely mis-budget by reading the wrong one:

• Kaltmiete (cold rent): the rent for the bare apartment - just the space. This is what "Miete" alone usually means and what deposit caps and the Mietpreisbremse are calculated on.
• Warmmiete (warm rent): Kaltmiete + Nebenkosten (the running costs). This is what actually leaves your bank account each month.

Always compare flats on the Warmmiete, because a low Kaltmiete with high Nebenkosten can cost more than a higher Kaltmiete with low running costs. Note that "warm" doesn't always include electricity or even all heating - check exactly what the Nebenkosten cover (see Setting up utilities in a German flat).

What's inside Nebenkosten (Betriebskosten)

Nebenkosten - legally Betriebskosten - are the ongoing operating costs of the building, which the landlord may pass on to tenants only if the contract says so and only for cost types in the legal catalogue (Betriebskostenverordnung, BetrKV). The chargeable ("umlagefähig") ones include:

Not chargeable to you: the landlord's administration costs, bank fees, and - crucially - repairs and maintenance (Instandhaltung/Instandsetzung). Repairing the building is the landlord's cost, not a running cost. Anything one-off or to fix/improve the building can't be dumped into your Nebenkosten.

Typical Nebenkosten run about €2-3.50 per m² per month, so on a 70 m² flat roughly €140-245/month on top of the cold rent - heating being the swing factor and the reason an energy-efficient building is cheaper to live in (Electricity in Germany).

The advance-payment model, and why the annual settlement matters

Here's the mechanism newcomers miss: the Nebenkosten in your Warmmiete are a Vorauszahlung (advance) - an estimate, not the final bill. Once a year the landlord tallies the building's actual operating costs, divides them among tenants (usually by floor area, with heating partly by consumption), and sends you a Nebenkostenabrechnung (settlement):

• If your advances exceeded the real costs → you get a refund (Guthaben).
• If they fell short → you owe a back-payment (Nachzahlung).

A Nachzahlung of a few hundred euros is common, especially in years of high energy prices - so keep a buffer. Conversely, don't treat a refund as free money; next year's advance may be raised.

The 12-month deadline - your key protection (§556 BGB)

The single most useful rule for tenants: the landlord must deliver the settlement within 12 months of the end of the billing period (§556 Abs. 3 BGB). Consequences:

• Miss the deadline → the landlord generally loses the right to demand a back-payment for that period. Late Nachzahlungen are usually unenforceable.
• You still get any refund owed to you even if they're late - the deadline protects the tenant, not the landlord.
• You have the right to inspect the underlying receipts (Belegeinsicht) and to object within 12 months of receiving the settlement if something looks wrong.

So if a landlord sends you a back-payment demand for a period more than a year old, check the dates before paying - it may be time-barred.

How the costs get split (the Verteilerschlüssel)

Your share of each cost is set by a distribution key (Umlageschlüssel) in your contract - and which key applies matters:

• By living area (Wohnfläche, per m²): the default for most costs (building insurance, caretaker, property tax) - your flat's m² as a share of the building's total.
• By number of occupants (Personen): sometimes used for water or rubbish.
• By actual consumption (Verbrauch): mandatory for a chunk of heating/hot water (below), and increasingly metered for water.
• Vacancy (Leerstand) is the landlord's cost: if other flats sit empty, the landlord bears their share - it can't be dumped on the remaining tenants. Check you're not being charged for an empty building.

Heating: the consumption rule (Heizkostenverordnung)

Heating and hot water follow their own law (Heizkostenverordnung): at least 50-70% must be billed by your measured consumption, not floor area - via radiator allocators (Heizkostenverteiler) or a heat meter. Consequences:

• A heating bill split purely by m² is usually wrong and challengeable.
• If the landlord fails to meter consumption at all, you can cut your heating share by 15%.
• The annual reading (someone visits to read the allocators, or they transmit remotely) feeds this - be home or arrange access.

The Grundsteuer reform: why your 2025 Nebenkosten may jump

A genuinely current issue: Germany's property tax (Grundsteuer) was reformed from 2025, and it remains chargeable to tenants (if your contract passes it on, which most do). Many municipalities raised their Hebesatz (multiplier) at the same time, so a lot of tenants are seeing noticeably higher Grundsteuer flow through into their Nebenkosten from the 2025 billing period onward. Points:

• It's a legitimate pass-through where the contract allows it - not an error to dispute, though you can check the figure.
• A landlord can issue a back-claim within 3 months of a revised Grundsteuer notice, but only against tenants who lived there in the relevant period.
• If your Nebenkosten advance jumps, this reform is often why - budget for it.

How to check your Nebenkostenabrechnung

A large share of settlements contain errors. Worth checking:

• The distribution key (Umlageschlüssel): is your share based on the agreed method (usually m²), and is your flat's size right?
• Only chargeable items: scan for repairs, maintenance, or admin costs sneaked in - those aren't umlagefähig.
• Heating split: by law, heating/hot water must be billed at least 50-70% by actual consumption, not purely by floor area (Heizkostenverordnung) - a purely area-based heating charge is often wrong.
• The period and deadline: does it cover a 12-month period, delivered within the following 12 months?
• Your advances: do the Vorauszahlungen listed match what you actually paid?

If something's off, object in writing within the 12-month window (the Einwendungsfrist - you have 12 months from receiving the settlement to raise objections) and ask for Belegeinsicht (the landlord must let you inspect the original invoices, in person or by copy). A Mieterverein (The German rental contract) will review it for you.

Flat-rate Nebenkosten (Pauschale): some contracts set a fixed monthly Nebenkosten amount with no annual settlement - you pay the flat rate and there's no refund or back-payment either way. Convenient and predictable, but you can't reclaim an overpayment, and it's separate from the advance-payment (Vorauszahlung) model above. Check which your contract uses.

Budgeting for it

• Treat the Warmmiete as your true rent, and additionally keep a small buffer for a possible year-end Nachzahlung.
• Remember some costs are usually separate on top of even the Warmmiete: household electricity (your own provider contract - Electricity in Germany), internet, and the Rundfunkbeitrag.
• When comparing flats, ask the landlord for the current Nebenkosten level and recent settlements - a suspiciously low advance today can become a painful Nachzahlung later.

Frequently asked questions