Practical regulations
Eco bonus in a condominium: how it is split
The eco bonus is the tax deduction available in Italy for energy efficiency renovation of buildings, including condominium common areas: thermal cladding, replacement of the centralized heating system, solar shading. In a condominium the expense affects the whole building, not a single owner, so splitting it among unit owners follows precise rules under the Civil Code and cannot be improvised. Getting the allocation criteria or the assembly majorities wrong exposes the resolution to challenge and can jeopardize the related tax benefit. This guide explains how the works are approved, which shares are used to split the cost, and how the property manager must document everything for the deduction.
Which works qualify for the condominium eco bonus
The condominium eco bonus applies to works on common areas that improve the energy performance of the building as a whole: thermal insulation of dispersive surfaces (external cladding), replacement of centralized heat generators with more efficient systems, installation of solar shading and building automation.
It differs from ordinary maintenance precisely because it produces a certifiable improvement in the energy class, attested by a qualified technician through an energy performance certificate issued before and after the works. This technical aspect does not change the legal nature of the resolution: it remains an extraordinary maintenance intervention on common areas, governed by Article 1120 of the Civil Code.
The assembly resolution and required majorities
Since these are innovations or extraordinary maintenance on common areas, the resolution requires the majority set by Article 1120 of the Civil Code for energy efficiency works: a majority of those attending representing at least one third of the value of the building. This is a reduced threshold compared to ordinary innovations, precisely to favor this type of work.
The meeting agenda must clearly state the scope of the works, the preliminary estimate, the proposed cost allocation and any option for tax credit transfer or invoice discount, so that each owner can make an informed decision about their financial commitment before voting.
The allocation criterion: general shares or heating shares
The general rule under Article 1123 of the Civil Code requires common area costs to be split in proportion to the value of each owner's property, that is, according to the general ownership shares recorded in the shares table.
However, if the works specifically concern the centralized heating system, the criterion under Article 1123 combines with the rules on heat metering: the cost is split based on actual consumption recorded by heat cost allocators or individual meters, not on ownership shares. Mixed interventions, such as cladding plus heating system, must therefore be broken down in the estimate, allocating each item to the correct criterion.
An owner who has not yet adapted their unit's heating system can still be required to contribute if the resolution is valid: any objection must be raised by challenging the resolution within the legal deadlines, not by refusing to pay the installment.
Tax deduction and the property manager's role
The eco bonus deduction is due to each owner in proportion to the share of expense actually paid and documented, not to their abstract ownership share: this is why the property manager must keep the traceable bank transfers, invoices addressed to the condominium and the allocation resolution, in order to certify to each owner the exact amount attributed to them.
If the assembly opts for tax credit transfer or invoice discount, the property manager collects the individual choices, since each owner can independently choose between direct deduction, discount or credit transfer, and reports the data to the relevant platforms, keeping separate accounting for the subsidized works distinct from the ordinary management fund.
Frequently asked questions
Can an owner be excluded from payment if they do not use the tax deduction?
No. The cost approved for common areas is owed by all owners according to the approved allocation criterion, regardless of whether an individual owner intends to benefit from the personal tax deduction. The deduction is an individual tax advantage linked to the expense incurred, not a condition for the obligation to participate in the cost split approved by the assembly.
What majority is needed to approve an eco bonus intervention in a condominium?
For energy efficiency works on common areas, Article 1120 of the Civil Code sets a reduced majority: a majority of those attending the assembly representing at least one third of the value of the building. The ordinary majority for innovations would be higher, but the legislator wanted to favor this type of work with a more accessible threshold.
Are general ownership shares or heating shares used to split the cost?
It depends on the works. For works on the building envelope, such as thermal cladding or solar shading, general ownership shares apply under Article 1123 of the Civil Code. For works on the centralized heating system, the heat metering criterion applies instead, based on actual consumption recorded by heat cost allocators or individual meters.
How is the individual expense documented for tax deduction purposes?
The property manager must keep the traceable bank transfers, invoices addressed to the condominium and the assembly minutes with the approved allocation plan, and upon request issue each owner a statement with the exact amount of expense attributed to them. This document is what allows the owner to correctly claim the deduction in their tax return.
Can condominium management software help with eco bonus accounting?
Yes. A platform like AmministraPro allows separate accounting to be kept for the subsidized works, automatically applies the correct allocation criterion based on the type of work, whether general shares or heating consumption, generates the cost allocation plans, and keeps the documentation needed for the deduction organized and verifiable over time.
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