External Thermal Insulation on a Condominium Facade: Rules and Costs

The external thermal coat is the insulation system applied to the outside of the perimeter walls to reduce heat loss. Since it improves energy efficiency but changes the appearance of the facade, its execution must be resolved by the owners' meeting as an energy upgrade, with the majorities set by Article 1120 of the Italian Civil Code. The insurmountable limit is architectural decorum: if the works appreciably alter it, a majority is not enough and the consent of all owners is required. The cost is split by thousandths (millesimi) under Article 1123.

Why a qualified resolution is needed

The coat affects a common part, the facade, and improves the building's performance. Works aimed at energy saving fall among the facilitated innovations: they can be approved with the favourable vote of the majority of those present representing at least half the value of the building in thousandths. This is a qualified majority, lower than the ordinary one for innovations, precisely to encourage efficiency works.

The manager must place the item clearly on the agenda, attach the quotes and the technical report, and accurately record the majorities reached in the minutes. A resolution that is imprecise about the subject or the majorities exposes the condominium to challenges.

The architectural decorum limit

Article 1120 prohibits innovations that alter the building's architectural decorum. This prohibition is unconditional: it is independent of the majorities reached and applies even in the face of changes already made by some owners. This means that, if the coat appreciably compromises the building's aesthetics, the resolution can be approved only with the unanimous consent of all owners. Even a single dissenting owner can object and act for the restoration of the original features.

In practice the coat rarely overturns the facade, but its impact must be assessed carefully on buildings of value, on cornices, floor lines and other decorative elements. A design respecting the original materials and colours reduces the risk of dispute.

Respecting exclusively owned property

The coat cannot significantly reduce the space of exclusively owned property. If, for example, increasing the wall thickness noticeably reduces the depth of a single owner's balcony or terrace, the resolution may be void in the part where it affects the individual right. The works must therefore be designed taking projections, parapets and openings into account, so as not to sacrifice the owners' rights.

How the cost is shared

• General rule: common cost split by thousandths of ownership under Art. 1123, because the coat rests on the common facade.
• Any tax incentives follow the rules of the bonuses in force at the time of the works and do not change the internal split criterion.
• Accessory works on exclusively owned parts remain the single owner's responsibility.
• The resolution must state amount, firm, timing and split criterion to be fully valid.

The manager's role

The manager coordinates the entire process: collecting quotes, appointing the designer and site supervisor, managing obligations towards owners and any building permits. They must also ensure accounting transparency, separating each owner's share and reporting the progress stages. Orderly management avoids misunderstandings over works that are often significant in amount and duration.

To plan the works, split the shares and keep payments and documents under control, a dedicated management tool makes the difference. With AmministraPro you can handle quotes, apply the thousandths tables and follow the site's progress on a single platform: discover the features on /funzioni and the plans on /prezzi.