Replacing common-part windows in a condominium

Replacing the windows and frames of the common parts concerns the windows of stairwells, entrance halls, technical rooms and other condominium spaces. Unlike the windows of individual apartments, these belong to all the owners, and replacing them with thermal-break frames and double glazing reduces losses, improves safety and enhances the building. Before resolving, however, one often-misunderstood point must be clarified: which windows are truly common and which remain individual property.

Common windows and private windows

The windows that light and ventilate stairwells, landings, common corridors, meter rooms and other condominium spaces are common parts: their maintenance and replacement fall on the condominium. The windows of individual apartments, by contrast, are the exclusive property of the owner, who replaces them at their own expense. The fact that all the windows face the same facade does not make them common: what matters is the function, that is, whether the frame serves a condominium space or a private unit.

From this distinction follows who pays: for common windows the cost is the condominium's, for private ones the individual owner's. Confusion on this point is the source of many disputes at the allocation stage.

The constraint of architectural decorum

Even when the frames are private, their replacement may meet a limit: the architectural decorum of the building, protected by Articles 1120 and 1122 of the Italian Civil Code. If the condominium regulation prescribes a uniform model, colour or material for windows visible from outside, the owner must respect it. For common windows, instead, it is the meeting that chooses the type of frame, which must harmonise with the overall appearance of the building. A radical change that alters the facade aesthetics requires a more careful assessment and, in some cases, higher quorums.

How the replacement is resolved

Replacing deteriorated common frames is maintenance: the meeting resolves it by ordinary majorities. If instead the works aim at energy improvement, with high-performance frames that reduce consumption, it can fall among the innovations for containing energy consumption under Article 1120, second paragraph, with the reduced quorum of a majority of those attending representing at least half the value of the building. It is always advisable to obtain comparative quotes and check the technical certifications of the frames proposed.

The allocation of costs

Costs for common-part frames are split among all owners according to the thousandths (millesimi) of ownership, under Article 1123 of the Italian Civil Code, because they serve the whole building. If, however, a portion of the frames serves only part of the building, for example the windows of a single stairwell in a building with several stairwells, the cost falls only on the owners of that stairwell, under the partial-service rule. This is why it is important to map precisely which frames serve which spaces.

Energy and safety benefits

Replacing old single-glazed frames with thermal-break, double-glazed windows produces concrete benefits: fewer losses in stairwells, better acoustic insulation from external noise, greater security against intrusion. In older buildings, common frames are often the weak point of the envelope, and their renewal coherently completes other measures such as roof or facade insulation.

To manage quotes, resolutions and splits of a window replacement in an orderly way, management software such as AmministraPro lets you distinguish common expenses from private ones, apply the correct allocation criteria and archive the technical certifications. The features are described on the /funzioni page and the plans with their costs on the /prezzi page.