The passive house or passivhaus was created as consequence of the 1980s oil crisis and the rise of the fuel prices. A group of physicians and engineers gathered together to find a way to reduce heating usage. From this collaboration new strategies were designed at an architectural level. In 1991 the first passive building was finished in Germany and, since then, the Passivhaus has been gradually introduced and its usage has spread all over the world. The Passivhaus certification, in German, or Passive House in English was originated from this, the standard that defines the buildings with the most energy-efficient architecture. The expression ‘passive’ is used to define the principle of capturing, storage and distribution capable of working on its own, without external energy nor gear, and that involves simple techniques. What’s a passive house then? It’s an ecological and efficient building made to greatly minimize the energy intake of the building through the planification of the global design. Specifically, it reduces 90% of energy intake compared to a regular house. The whole building is constructed with the purpose of creating protection from outside and making a comfortable environment inside without conventional air conditioning. These are houses created under bioclimatic principles – climate studies, orientation, solar radiation capturing during winter and protection during summer. They’re hermetic with air renovation through a ventilation system with a heat recovery unit that renews the air without heat loss. Its secret relies on combining a high interior comfort with a low energy intake, and at a very affordable price, which allows to amortize the investment of the building in a much shorter time compared to a regular one.