Split by Thousandths or by Consumption: Which Criterion to Apply

Compared

The thousandths criterion: the general rule

Article 1123 of the Italian Civil Code establishes that expenses for the preservation and enjoyment of common parts are split in proportion to each owner's property value, that is, by thousandths. It is the general criterion, applying to everything concerning the condominium as a whole: the manager's fee, the building insurance, the cleaning of stairs, the maintenance of the facade.

The logic is that whoever owns a larger share of the building benefits more from the preservation of common parts and bears the cost proportionally. The criterion is objective and stable, because it does not depend on variable use but on the value set in the thousandths tables, which remain the reference until they are corrected under the rules of Article 69 of the implementing provisions.

The consumption criterion: when use counts

Some expenses do not depend on the value of the unit but on the use made of it. For central heating the rules require metering of heat and allocation according to the technical standard UNI 10200, which distinguishes a share tied to actual voluntary consumption and a fixed share for the plant's capacity. Whoever consumes more pays more, but a common part remains for involuntary costs.

The same principle applies to water when individual meters exist: the measured consumption of each unit determines the charge. The consumption criterion, however, requires a technical condition: without reliable measuring instruments, it is not applicable. In the absence of meters or allocators, the expense reverts to thousandths or other resolved criteria.

Expenses with a specific criterion: Article 1124

Between thousandths and consumption there is a third case, that of expenses with their own criterion provided by law. Article 1124 of the Italian Civil Code governs the maintenance and replacement of stairs and elevators: half the expense is split by thousandths and half in proportion to the floor height of each unit. It is a mixed criterion that considers both value and use, because those living on the upper floors use the stairs more.

Article 1126 also dictates a specific rule for the expenses of a flat roof under exclusive use. These legal criteria prevail over a generic split by thousandths: applying them correctly means knowing which rule governs each type of expense, not reducing everything to a single criterion for convenience.

Mixed cases: one expense, two components

Many real expenses combine several criteria. The central heating bill has a consumption share and a fixed thousandths share; water can have a part on individual meter and a common part for losses and condominium uses. Handling these cases means breaking the expense into its components and applying the correct criterion to each.

The most common mistake is forcing the entire expense onto a single criterion. Splitting all the heating by thousandths ignoring the metering, or all by consumption ignoring the fixed share, produces charges that do not comply with the rule and are easily disputed at the meeting. Correctness lies in the breakdown, not in the simplification.

How software applies the right criterion

Applying different criteria by hand for each type of expense, with consumption shares and thousandths shares to combine, is laborious and error-prone. A management platform associates the correct criterion with each expense account and also handles mixed cases, automatically splitting the thousandths part and the consumption part according to the readings entered.

AmministraPro allows configuring multiple allocation tables for the same condominium and distinguishing expenses by criterion, so heating with metering, individual water, and common expenses each follow their own rule without manual calculations. The allocation features are described on the /funzioni page and the plans on the /prezzi page.

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