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KI-Symbolbild: Ein helles Badezimmer mit Wassertropfen an der Duschglaswand und Blick aus dem Fenster auf alte Wiener Dächer am Morgen.
Practical article Renting & everyday living Austria

Distribute water by consumption instead of area: Preparing the agreement under § 17 Absatz 1 a MRG

A planned consumption allocation requires more than a few new meters. Combine measurability, economic viability, a written agreement and a correctly calculated majority.

Automatically translated – the German version is legally binding. Show original (German)

Published
19 Oct 2026
Research as of
17 Oct 2026
Applies to
Austria
For whom
Searchers & tenants
Article ID
WX26-P02-0051

Reader question: What prerequisites and what tenant majority does a planned consumption-based cost allocation require in an Austrian rental building?

In the Austrian rental building several residents want to allocate certain water costs in future according to consumption instead of floor area. Buying individual meters does not by itself solve this task. §17 Absatz 1 a MRG contains a special agreement procedure with technical, economic and legal prerequisites. [MRG17]

The article assumes that this MRG framework applies to the affected tenancies. Heating and domestic hot water costs with their own statutory allocation regime are not assumed to be subject to the same free agreement without examining them. [MRG1]

Which specific cost item should be distributed differently?

Start with a specific cost item and the key currently used. Which expenses actually depend on consumption? Which should remain distributed according to the previous basis? A new agreement on “all ancillary costs” would be a different and much broader question.

§17 Absatz 1 a presupposes consumption-dependent expenses and requires that the shares can be determined by measuring devices with economically reasonable cost effort. [MRG17] Obtain an appropriate technical description for this: recorded draw-off points, scope of measurement, installation and ongoing costs. A single existing meter does not yet prove a complete, economically suitable concept for all units.

Calculate the majority by rented objects

The provision envisages a written agreement between the landlord and a majority of at least two thirds of the tenants, calculated according to the number of rented rental objects. [MRG17] That is not simply a vote by the people present or by square metres.

In the fictitious building there are nine units considered for this, seven of which are rented. For the example constellation all relevant allocations are assumed to have been clarified. Two thirds of seven yield more than four; accordingly at least five correspondingly allocated consents are required. Four are not enough for this assumed count. In addition, the landlord must be party to the written agreement.

The example does not replace examination of special constellations and representations. The two residents of a jointly rented flat are not simply counted as two additional rented rental objects.

Plan metering and remaining communal costs

With an appropriate agreement the recording of consumption shares must be tolerated. For shares not recorded despite reasonable efforts the law permits certain calculatory procedures according to the technical standard and limits the area thereby covered to 20 percent. General consumption remains to be allocated according to the statutory usable floor area ratio. [MRG17]

Therefore ask before deciding how gaps are to be treated and which common consumptions are to be shown separately. The article does not endorse any arbitrary estimation method. A flat residual amount must not appear as an allegedly measured individual consumption.

Hypothetical process from interest to agreement

A group of residents first gathers non-binding interest. Management then receives a concrete metering question. Only after the technical and economic clarification is a written agreement on the specified cost item prepared and the required participation checked.

Start date, initial readings, possible billing period and practical access dates are recorded in a comprehensible manner. The law allows for these expenses a twelve-month period deviating from the calendar year. [MRG17] A retroactive change for periods already billed is not thereby readily inferred.

Close outstanding prerequisites before an order

Record at the end whether scope of application, metering concept, cost effort and required agreement are actually clarified. A collection of signatures under a non-binding expression of interest is not treated as a completed allocation agreement. This way a consumption-based solution can be purposefully prepared without equating a mere desire for meters with an already effective new billing.

Sources and context

Created with the help of AI and editorially reviewed. General guidance only; not individual legal, tax or financial advice. Errors and later changes are possible.