Practical guide
How to allocate common service costs in a supercondominium
Allocating the cost of services shared by several buildings is the core of managing a supercondominium. The starting rule is Article 1123 of the Italian Civil Code, extended to these arrangements by Article 1117 bis: general expenses are split in proportion to property value, while services are allocated by use when the buildings derive different benefit from them. The operational step consists of correctly classifying each expense, applying the right supercondominium thousandths (millesimi) tables and distinguishing what is common to all from what serves only some buildings. This guide explains how to do it step by step, with the most common cases.
Step 1: classify each common expense
Before allocating, you must classify. Every supercondominium expense falls into one of three categories: a general expense concerning all buildings on the same basis, the expense of a service the buildings use to a different extent, or an expense concerning only some buildings and not all. Which criterion and which table to apply depends on this classification.
A concrete example makes the difference clear: maintenance of an access driveway common to all is a general expense to be allocated by supercondominium thousandths, whereas central heating consumption is a service to be allocated partly by consumption and partly by installed power, and the maintenance of a gate serving only two buildings out of four must be charged to those two only.
Step 2: apply the Article 1123 criterion
Article 1123 sets out three rules that combine within a supercondominium.
- Paragraph 1: expenses for the preservation and enjoyment of common parts are allocated in proportion to each owner's property value, that is, by thousandths
- Paragraph 2: for services intended to serve the participants to a different extent, expenses are allocated in proportion to the use each can make of them
- Paragraph 3: if an asset or service is intended to serve only some of the buildings, the related expenses fall only on the group that benefits, not on all
Step 3: use the supercondominium thousandths tables
A supercondominium requires dedicated tables, different from the internal tables of each building. The supercondominium tables measure the weight of each building on the shared assets and services, taking into account the overall value of each building relative to the others. Once the expense has been allocated among the buildings using the supercondominium table, each building splits it internally among its owners using its own tables.
This double step, first among the buildings and then within each building, is the distinctive feature of supercondominium accounting. Skipping it, by applying the internal tables directly to common expenses, produces incorrect allocations and challengeable resolutions.
Step 4: handle consumption-based services
For measurable services, the use-based criterion translates into consumption-based allocation. The typical case is central heating shared by several buildings: the UNI 10200 standard indicates how to split the expense between a share linked to voluntary consumption, measured by heat cost allocators, and a fixed share linked to installed power and heat losses. Similarly, water can be allocated on the basis of sub-meters, where present.
Applying a consumption-based criterion where measuring instruments exist is not only correct but often required, because allocating a measurable service purely by thousandths can be challenged by participants who consume less.
Step 5: document the allocation and communicate it to the buildings
The allocation must be documented transparently, so each building can verify how its share is composed: which services, on what criterion, on what basis. Clarity here prevents most disputes and challenges.
Digital management greatly simplifies this step. With AmministraPro you can set up distinct allocation tables for common services, apply consumption-based criteria where needed and produce readable statements for each building: the allocation features are described on the /funzioni page, while the plans are listed on /prezzi.
Frequently asked questions
Are all supercondominium expenses allocated by thousandths?
No. Article 1123 of the Italian Civil Code provides three combined criteria: general expenses are allocated by thousandths, services that the buildings use to a different extent are allocated by use, and expenses for assets or services intended to serve only some buildings fall only on those. Applying the thousandths criterion to everything is a common mistake that can make the allocation resolution challengeable when a service does not serve everyone equally.
How is central heating shared by several buildings allocated?
Heating is a measurable service, so it must be allocated by use under Article 1123 paragraph 2. The UNI 10200 standard indicates how to split the expense between a voluntary consumption share, measured by heat cost allocators installed on the radiators, and a fixed share linked to installed power and system losses. Allocating a measurable service purely by thousandths is challengeable by those who consume less, so where measuring instruments exist the consumption-based criterion is the correct one.
What are supercondominium thousandths tables?
They are dedicated tables that measure the weight of each building on the assets and services common to several buildings, distinct from each building's internal tables. Allocation happens in two steps: first the common expense is split among the buildings using the supercondominium table, then each building splits it internally among its owners using its own tables. Applying the internal tables directly to common expenses skips a step and produces incorrect allocations.
Can a building be excluded from a common expense?
Yes, when the asset or service is not intended to serve it. Article 1123 paragraph 3 provides that the expenses of assets or systems intended to serve only some buildings fall exclusively on the group that benefits. If a gate, a system or a common area serves only some buildings, the others do not contribute to the related expense. This limited purpose must, however, be objectively apparent from the premises and the title, not merely a matter of choice.
How do you make the allocation transparent to the buildings of a supercondominium?
By documenting, for each expense, which criterion was applied, on which table and with what calculation basis, so each building can reconstruct the composition of its own share. Transparency prevents most disputes. Management software such as AmministraPro lets you set up distinct allocation tables for common services, apply consumption-based criteria where necessary and generate readable statements per building: the features are described on /funzioni and the plans on /prezzi.
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