Sometimes, the most innovative ideas arise in the most unexpected moments. For instance, this happened in 1988 when professors Bo Adamson and Wolfgang Feist originated the concept of "Passivhaus" (passive house in English) from an interesting conversation. The term refers to a construction philosophy that minimizes energy efforts as much as possible. In other words, it alludes to homes that significantly reduce energy consumption by utilizing natural resources and adopting the highest efficiency standards. The result is a lower environmental impact and significant savings for the occupants. Estimates of heating consumption are astonishing, with savings of up to 90% compared to typical constructions and 75% compared to new buildings based on energy efficiency standards and environmental respect.
The Passive House Concept
Therefore, to achieve such remarkable results, which are even more significant in temperate climates, a passive house must rely on resources inherent in bioclimatic architecture and opt for passive cooling. Hence, this enables the generation of heat or cold without any mechanical devices. As can be observed, what Bo Adamson and Wolfgang Feist proposed in Germany in the 1980s was a departure from the prevalent construction style followed (and continues to be followed in most parts of the world), which had deviated from concepts that humans had historically employed to adapt to various climates. It was not until the Industrial Revolution that they began to use modern heating techniques.
Characteristics of Passive Houses
Now that we have a clear understanding of what a passive house is, we can outline its main technical characteristics:
• Thermal insulation: Passive houses are built with materials that provide high-quality thermal insulation. This insulation drastically reduces the energy required for heating or cooling the different spaces. While energy efficiency is a top goal, occupant comfort is equally important.
• Bioclimatic design: These constructions must make optimal use of local climatic conditions to minimize energy consumption for improved climate control. Therefore, the design should consider factors such as solar exposure/protection, orientation, and environmental conditions.
• Airtightness: It is essential to prevent and control air leakage, as it leads to heat or cold loss. Whether we refer to it as airtightness or envelope airtightness, this characteristic is crucial for passive houses.
• Absence of thermal bridges: Thermal bridges refer to points in the structure that allow heat transfer between the interior and exterior. Passive houses must not have weak points through which heat or cold can be lost, depending on the climate. Otherwise, their effectiveness will be reduced, resulting in higher energy consumption.
• Windows and doors with high energy efficiency: While we mentioned the importance of quality materials, windows and doors deserve special attention. They are often the top source of heat loss or gain in a house. Moreover, passive houses should incorporate models designed to minimize these losses while optimizing natural light utilization.
• Use of renewable energy: Passive houses prioritize using renewable energy sources such as photovoltaic or thermal solar panels, making them even more environmentally friendly.
• Mechanical ventilation with heat recovery: Finally, passive houses require an automated ventilation system that not only refreshes the air, thus maintaining its quality, but also recovers energy from the outgoing air to preheat the incoming air.
Constructing a Passive House
Anyone interested can embark on the construction of a passive house. To do so, they must find a plot of land and have a project designed by an architect specialized in this concept, ensuring that it meets the necessary standards. Although new constructions usually implement this model, older buildings in retrofitting undergoing renovation can also apply it.
Financing for a Passive House
It should be noted that these projects may require financing to cover the various expenses involved in the construction of a passive house. UCI Mortgages provides the perfect mortgage or loan for this type of construction, as we are particularly committed to environmentally-friendly projects. Furthermore, this type of financing is supported by the European Central Bank, as it has been promoting any kind of "green" project that is initiated, and passive houses undoubtedly fall into that category.