Would you like to live in a house that remains warm in winter and cool in summer, spending very little money on air conditioning or heating?
Imagine a house in which the walls and windows trap the heat of the Sun in winter and retain it indoors. A house that protects from the heat in summer by circulating the air wisely to stay cool, without the need for expensive heating or cooling systems. A house that isolates noise from the outside, efficiently ventilates the interior and consumes only 20% of the energy used by a conventional home. A house whose interior is always springtime, throughout the year.
Such a house is possible. It's called Passive house
Passive Houses. (from ELPAIS, 11/01/2017)
WHAT IS A PASSIVE HOUSE?
It is a house designed and built according to parameters established by Passivhaus certification, a standard model created in Germany that defines the most energy-efficient buildings and designed under bioclimatic criteria. This model extends beyond these bioclimatic criteria and adds the use of renewable energy so that the energy footprint of the house on the planet is null or almost null. The technical criteria for designing a passive house can be seen in detail here, and the objectives to achieve are these:
ADVANTAGES OF A PASSIVE HOUSE
More comfortable
More healthy
More efficient
IF YOU ARE INTERESTED IN A PASSIVE HOUSE
I am a Member of the Plataforma de Edificación Passivhaus (PEP) and Certified Passive House Designer by the Passive House Institute
History of the Passive House model
After the oil crisis of the 70s and 80s, German scientists set out to study how to reduce the expenditure on heating of buildings, based on studying the most suitable orientations, forms and materials for it. As a consequence, in 1991 the first house was built on these criteria, a group of 4 houses in Darmstadt (photo). In September 1996 the Passivhaus-Institut was founded in Darmstadt itself with the aim of promoting and controlling this standard. Since then, the model has spread throughout the world, where we can already find 30,000 buildings built according to this standard..
In Spain, the Passivhaus Building Platform was created in 2008. It is a non-profit association that promotes passive buildings in Spain and is part of the International Passivhe House Association and EuroPHit. The Passivhaus Building Platform is the institution that certifies the standard that grants various types of certificates depending on the degree of compliance with the requirements of the model, which measure four variables: energy demand for heating, cooling, total energy consumption and tightness of the building.
The first building certified under the Passivhaus standard in Spain was built in 2009, and it is the Assyce-Ecoholística house in Moraleda de Zafayona, Granada. In 2019 the first home with a Passivhaus Premium Certificate in Spain was certified in Soto del Real, the most demanding certificate, which is awarded to those buildings that have a very low energy consumption and are capable of being completely self-sufficient.
Technical criteria for a Passive House project
These criteria are those that must be followed when designing a Passive House. They can be consulted on the website of the Passivhaus Building Platform, and are the following:
- Thermal insulation: It is the "coat" that surrounds the house. It must be very insulating, in such a way that in winter the sun's heat enters through the window but cannot get out. And in summer, awnings and shading elements prevent heat from entering the house. The thickness of the closings will depend on the location of the building and the climate of the area.
- High quality windows and doors: They are the most sensitive elements, where heat escapes and air passes. They must be very insulating, with double or triple glass, and very low thermal transmittance. They must let the Sun pass in winter but not let the heat in in summer.
- Eliminate thermal bridges: A "thermal bridge" is an area of high thermal conductivity where heat easily enters or leaves. It usually occurs in corners, joints, shafts ... These are areas that, if not well insulated, can cause mold and condensation to appear. Aluminum windows must have "thermal break", which means that there is no part of the metal that is at the same time in contact with the interior and exterior of the wall.
- Hermeticity: The house must be very hermetic to the passage of air, since an uncontrolled entry or exit of air leads to the entry or exit of heat. The regulation gives a maximum value of air flow between the interior and the exterior of the house when it is all closed.
- Mechanical ventilation with heat recovery: The house must be hermetic because the entry and exit of ventilation air must be mechanically controlled, and there must also be heat recovery units (the air that comes out exchanges energy with the one that enters to minimize loss) . This ensures adequate ventilation with minimal heat loss.
