The expression “breathing façade” is widely used in marketing, but technically speaking, a façade does not “breathe” like a living organism. What it can do, however, is manage vapor transfer and moisture in such a way that the wall remains dry and performs as intended. This is where two different concepts—often confused—come into play:

• vapor permeability (diffusion through materials), and
• ventilated façades (air circulation within a cavity).

A true ventilated façade consists of an outer cladding layer, a continuous air cavity, and protected thermal insulation. Air within the cavity moves through the stack effect, evacuating part of the moisture and reducing the risk of condensation in sensitive layers. Typical benefits include improved control of wind-driven rain, protection of the thermal insulation, more stable temperatures of the supporting wall, and, in many cases, increased durability.

The myth arises when “breathing” is invoked to justify solutions lacking airtightness continuity or a proper vapor control layer. Condensation does not disappear through the use of “natural materials,” but through a correctly designed layer build-up: a more airtight interior, vapor control where required, properly sized thermal insulation, and the elimination of thermal bridges. If warm, moist indoor air infiltrates cold zones, condensation will occur even in so-called “permeable” walls.

In terms of energy performance, a ventilated façade is not automatically “better” than an ETICS system. Performance depends on detailing, continuity of insulation, thermal bridge treatment, airtightness, and execution quality. The conclusion is clear: “breathing façades” are a technical reality only when referring to controlled vapor diffusion and/or designed ventilation. Otherwise, the term is largely a commercial simplification.

(Photo: Freepik)