Practical guide
Splitting central heating costs in a condominium
In buildings with a centralized heating system, splitting the heating bill is one of the most delicate calculations of the year, because it combines technical standards with civil law rules. Since 2016, individual heat metering has been mandatory where technically feasible, requiring the cost to be divided into a fixed share, linked to ownership and installed capacity, and a variable share, linked to actual consumption recorded by thermostatic valves or heat cost allocators. The building manager must apply the correct apportionment shares, process the reading data supplied by the metering company, and present it in a statement the assembly can actually understand. Here is how it works in practice and how a platform like AmministraPro streamlines every step.
Fixed share and consumption share: what the standard requires
The relevant technical standard, UNI 10200, distinguishes two components of the heating bill. The fixed share covers costs that exist regardless of consumption: depreciation and maintenance of the plant, heat losses in the distribution network, and the design and management costs of the service. The variable share instead pays for the energy actually drawn by each unit, measured by heat cost allocators or heat meters installed on individual radiators.
The fixed share is generally split according to ownership shares and, where available, the theoretical heating demand of each unit derived from its heat loss surface and exposure. The variable share follows actual consumption recorded during the heating season, read by the metering company appointed by the building.
The law does not impose an identical fixed percentage for every building: the metering regulation, attached to the assembly resolution that approves the switch to individual metering, sets the specific weight of the two shares for that particular plant, based on the technical report prepared by the designer.
When individual metering is mandatory
Legislative decree 102/2014, as amended by legislative decree 141/2016, requires the installation of heat metering systems in buildings with centralized heating, where technically feasible and cost effective. The stated goal is to encourage energy savings: those who consume less pay less, replacing the old criterion of purely ownership-based apportionment that did not reward virtuous behavior.
Where installing heat cost allocators is not technically feasible or is disproportionately expensive relative to the expected energy savings, the assembly may resolve to keep the traditional apportionment based on heating ownership shares, recording a technical report that justifies the exemption.
The resolution approving the switch to metering, or confirming the ownership-share criterion in the absence of technical feasibility, is adopted with the majorities required for innovations under article 1120 of the Civil Code and must be clearly minuted, since it forms the legal basis for every subsequent apportionment.
Heating apportionment tables
Alongside the general apportionment table required by article 68 of the implementing provisions of the Civil Code for general expenses, many buildings with centralized heating adopt a dedicated heating apportionment table, calculated under article 1123 of the Civil Code based on the potential use of the service: installed radiant surface, heated volume, exposure, and heat loss coefficients of each unit.
This dedicated table mainly serves the fixed share, while the consumption share disregards ownership shares entirely and follows the metered reading data. In buildings that have never adopted a distinct heating table, the manager can propose to the assembly that a qualified technician prepare one, an action that requires unanimity if it changes the legal apportionment criteria, or a qualified majority if it merely implements them with greater precision.
How AmministraPro handles the apportionment in practice
In the financial statement, the manager must show the two heating cost components separately, along with the criterion used to split each one among owners, so every owner can verify the amount charged. AmministraPro lets you configure the heating apportionment table separately from the general table, import the reading data supplied by the metering company, and automatically generate the combined apportionment of fixed and consumption shares for each unit.
The platform keeps a season by season history of readings, useful in case of disputes over consumption, and produces the individual statement each owner can check to verify consistency between their own consumption data and the amount charged in the financial statement.
Frequently asked questions
Who pays more, the fixed share or the consumption share?
It depends on the weight the metering regulation assigns to the two components for that specific plant, as defined in the technical report approved by the assembly. Generally the variable share rewards lower consumption, while the fixed share is owed by everyone regardless of consumption, since it covers the existence and maintenance costs of the shared plant. There is no identical percentage valid for every building: it must always be checked against the specific regulation approved for that building.
Can an owner who has closed all radiators avoid paying anything?
No. Even by closing every radiator, the owner still owes the fixed share, since they still benefit from the availability of the centralized service and contribute to maintenance costs and network losses that do not depend on individual behavior. Only the variable share can drop to zero if the heat cost allocators record no consumption during the heating season.
What happens if the assembly never approves a dedicated heating table?
In the absence of a dedicated table, apportionment follows the criteria set by the resolution that introduced metering, often referencing the general table for the ownership share and the reading data for the consumption share. It is still advisable for the assembly to resolve clear criteria, since lack of transparency about the calculation basis is one of the most frequent causes of disputes over the financial statement.
How does an owner verify that the apportionment is correct?
Owners are entitled to review the reading data for their own unit and the criteria used to calculate the fixed share, requesting them from the manager or consulting them directly if the building uses a platform with a dedicated portal. With AmministraPro, every owner can see their own statement and the breakdown between the fixed share and the consumption share, reducing the number of clarification requests sent to the manager.
Does individual metering apply to independent heating systems too?
No, the heat metering obligation concerns centralized plants serving multiple units from a single production source. Independent heating, with a separate boiler for each apartment, falls outside this rule because consumption is already individual and requires no condominium-level apportionment.
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