Water meters in an apartment building: when consumption may replace floor-area allocation

Consumption-based charges in an apartment building may be allocated by measured use. Section 17(1a) MRG requires a written agreement between the landlord and a majority of at least two thirds of the tenants, calculated by the number of rented units. The consumption must also be capable of being measured with devices at economically reasonable cost.

Floor area remains the statutory starting point. A qualified agreement opens the route to consumption allocation for individual consumption-based charges. Water meters alone therefore do not change the allocation key. The agreement, majority, measurement system and treatment of unmeasured parts must be checked together.

Floor area remains the starting point

Section 17(1) MRG generally allocates a unit’s share of the building’s total costs in proportion to its floor area compared with the floor area of the relevant flats and other units in the building. A different key requires a written agreement between the landlord and all tenants, or must follow from a specific statutory rule.

Section 17(1a) MRG creates a separate route for individual charges that depend on consumption. It applies where the shares of the flats or other units in total consumption can be established with measuring devices at economically reasonable cost. A property manager’s established practice does not replace these requirements.

Water charges and heating costs must be kept apart. This article addresses the special allocation of measurable consumption-based charges under section 17(1a) MRG. The Heating and Cooling Costs Accounting Act has its own accounting regime.

Prove the written agreement and two-thirds majority

Consumption allocation requires a written agreement between the landlord and a majority of at least two thirds of the tenants in the building. The calculation is based on the number of rented units. The file should therefore contain a reliable list of rented units and the recorded approvals.

The file should identify the charge covered, the start of the arrangement, the units included and the basis for calculating the majority. A new owner or manager must still be able to identify the applicable agreement. A reference in one service-charge statement does not by itself prove the required agreement and majority.

The article service charges in an apartment building places this issue in the wider review of permitted items, statements and vouchers. The present question remains limited to the special allocation of measurable consumption-based charges under section 17(1a) MRG.

Meters must be economically reasonable

Section 17(1a) MRG links consumption allocation to measuring devices that can establish each unit’s share of total consumption at economically reasonable cost. An apartment building therefore needs a traceable measurement system. The property file should connect each meter to a unit and record reading dates and the response to technical failures.

Once a valid agreement exists, each tenant must tolerate the recording of consumption in the tenant’s unit. That duty concerns the agreed measurement system. It does not cure an unclear or inconsistent measurement process and does not permit allocation outside the statutory conditions.

Before issuing a statement, the landlord should bring meter number, location, reading period, opening and closing reading and the relevant charge together. In a purchase, these records belong in the data room. Maintenance work, pipework and technical changes should be coordinated with the legal cost assessment, as explained in the article on maintenance work in an apartment building.

Classify measurement gaps and calculated shares

If consumption shares cannot be recorded despite reasonable efforts, section 17(1a) MRG allows a calculation method where that method reflects the state of technology. This rule addresses a specific measurement gap. It is not a general permission to replace missing readings with unsupported estimates.

The floor area for which consumption shares are calculated in this way may not exceed 20 percent. The statement should therefore show which units are affected, why measurement was impossible and how the calculated share was obtained.

A short fault and evidence record is useful. It should identify the meter, the contact or repair attempts, the period without a reading, the method used and the floor area of the affected unit. This makes the exception from regular measurement reviewable later.

Separate common-area consumption and the accounting period

The part of the charge attributable to consumption in the common areas of the building is allocated in proportion to floor areas under section 17(1) MRG. A consumption statement must therefore keep this part separate from the readings of individual flats.

For these consumption-based charges, the landlord may provide for a twelve-month accounting period that differs from the calendar year. The chosen period must be clear. Readings, invoices and advance payments should refer to the same period or be reconciled transparently.

The cost statement should show at least the consumption shares of the units, the common-area share, the accounting period and the readings used. That structure keeps the special rule separate from a general service-charge review.

Review file for landlords and property managers

For a consumption statement, the landlord and property manager should collect the written agreement, the two-thirds calculation, a list of all rented units and the measurement system. The file should also contain meter assignments, reading records, invoices and the allocation of common-area consumption.

Where values are missing, the file should record the reasonable efforts to obtain them, the calculation method used and the affected floor area. Before a sale, the data room should identify open measurement issues, technical defects and the accounting position for the latest period.

This structure answers whether consumption may replace floor area. It also prevents the special rule in section 17(1a) MRG from being applied to heating costs, charges that cannot be measured or a general service-charge statement.

Next steps and legal updates

For the review, keep the agreement, majority calculation, unit list, measurement system, readings, invoices and common-area allocation together. New articles and legal updates from the firm are available through BRANDaktuelle legal updates.