Danilo · Updated 2026-09-12 · Sources: Swiss Code of Obligations Art. 253ff., Art. 257a–257b (fedlex.admin.ch); Swiss Tenants' Association (Mieterverband), fact sheet on Nebenkosten; ch.ch, tenancy law
Net Rent, Gross Rent and Nebenkosten – What Does a Listing Actually Say?
Take a made-up example: one listing says "CHF 1'850", another says "CHF 2'100" – and the cheaper-looking one can still end up costing more. The reason is almost always the same: one figure is net rent, the other is already gross rent including ancillary costs, and setting them side by side without checking which is which compares two different things. This guide explains what the terms mean, what a landlord may actually bill as ancillary costs under Swiss law, and how Zügle handles a listing that states no rent at all.
Net, gross, Nebenkosten: three terms, one missing amount
Net rent (Nettomiete) is the pure charge for using the flat, excluding ancillary costs. Gross rent (Bruttomiete) is net rent plus ancillary costs together – the amount that actually leaves your account every month. Nebenkosten themselves are defined in law: Art. 257a of the Swiss Code of Obligations (OR) says they are "the payment for services provided by the landlord or a third party that relate to the use of the property" – heating, hot water and similar operating costs, not the value of living there as such.
Ancillary costs are only owed if they were specifically agreed in the lease. If the lease says nothing about them, they count as included in the rent – a landlord cannot add a new ancillary-cost item after the fact that was never named in the contract. A listing that just says "CHF 1'850 + NK" tells you nothing yet about what those costs will actually cover; that lives in the lease, not in the ad.
Akonto or flat-rate – two very different arrangements
Ancillary costs are almost always billed in one of two ways:
- Akonto (advance) payment: you pay a monthly advance (in our made-up example,
CHF 150), and once a year the landlord issues a Nebenkostenabrechnung (annual statement) that sets actual consumption against what you paid in advance. Overpaid, and you get a refund; underpaid, and you owe the difference. Art. 257b OR ties the ancillary costs to the landlord's actual expenditure, so under an akonto arrangement the annual statement has to show those real costs, and you have the right to inspect the underlying receipts.
- Flat rate (Pauschale): you pay the same fixed amount every month regardless of
actual consumption. There is no annual statement and no back-payment – but also no refund if you heated very little. A flat rate is more convenient, but can work out either way depending on how sparingly or generously you actually use the flat.
A listing rarely states which of the two is meant – "ancillary costs CHF 150" can be either akonto or flat rate. That is worth clarifying before viewing the flat, or at the latest before signing, not after the first statement arrives.
What may actually be billed as ancillary costs?
The law mainly requires two things of an ancillary-cost item: that it is named as such in the lease, and that it relates to actual, use-related expenditure. It offers no exhaustive list. In practice that typically covers heating, hot water, the caretaker, shared electricity in the stairwell or laundry room, and similar running costs. It typically does not cover building repairs, the landlord's own administrative costs, or reserves set aside for future renovations – those are already covered by the net rent, because they concern the upkeep of the property itself rather than its use. What is admissible in a specific case depends on the exact lease clause and, in a dispute, on case law; if in doubt, it is worth asking the local conciliation authority (Schlichtungsbehörde) or a tenants' association before accepting or contesting a statement.
Heating: the largest moving part
Of all ancillary costs, heating varies the most – between a mild and a cold winter, between a well- and a poorly-insulated flat, between a top floor and a ground floor. That is one reason a future flat's ancillary costs can only ever be an estimate before you have actually lived there – neither the listing nor the landlord can tell you in advance exactly what you will use in your first winter. Comparing an older, poorly-insulated flat with low net rent to a newer, well-insulated one with higher net rent can shift meaningfully once ancillary costs are added in.
Why comparing net rent to gross rent misleads a move decision
This is the real trap for a move decision: continuing the made-up example, if your current flat is quoted at CHF 2'000 gross (rent plus ancillary costs), and you compare that to a listing's net rent of CHF 1'850, the move looks CHF 150 cheaper than it really is – once the new flat's own ancillary costs are added, that gap can shrink or reverse entirely. These figures are invented for illustration only, not typical or average rents. The only fair comparison is gross against gross, or – when only a net rent is known – adding a realistic ancillary-cost estimate before comparing.
Zügle handles this by comparing on the same basis: when only a gross rent is published for a listing, Zügle uses that; when only a net rent is available, it is treated as such rather than silently equated with a gross figure. Both sides of a comparison – your current home and the listing – must rest on the same basis, or the comparison quietly stops being one.
"Rent on request" – when a listing states no figure at all
Some listings, especially for unusual properties or where the rent is meant to be negotiable, state no amount at all – neither net nor gross. Such a flat can look attractive at first glance because no high price scares you off, but that is exactly what makes it useless for a comparison: an unknown rent is neither low nor high; it is simply no number. Zügle deliberately does not rank such a listing and never suggests it as a saving – a listing with no rent would otherwise look like free housing and would drown out any genuine saving elsewhere. Anyone who still wants to consider it has to ask the landlord for the figure and enter it themselves.
Ancillary costs in your Zügle comparison
When you enter a listing manually or let it be read in automatically, it is best to enter the net rent you know and the ancillary costs separately, when both figures are available – that most closely matches what will end up on the lease. If only a gross rent is known, that single figure is enough; Zügle treats it accordingly. The same applies to your current home: the more precisely its ancillary costs are known, the more reliable the comparison to the new flat becomes.
What these figures don't show
- An ancillary-cost statement is always an estimate in advance, never a guaranteed
amount – heating costs depend on the winter and on individual habits.
- Whether a particular item may legitimately be billed as an ancillary cost in a
specific lease is a case-by-case question; in a dispute, the conciliation authority decides, not this page.
- This is not legal advice for your specific lease, but a general explanation of
publicly accessible provisions of the Code of Obligations.
Run it with your own numbers
Whether a move pays off depends on the actual figures for your current home and the specific listing; a net-versus-gross mix-up distorts them.