What is Passivhaus Design? Low consumption buildings that save energy, with excellent insulation, that are respectful of their environment and more comfortable for the people who occupy them. Cool, right? 

That is the essence of the Passivhaus Design, innovative constructions that pursue maximum efficiency and sustainability. If you want to know more about this type of design, keep reading! 

What Is Passivhaus Design?

Passivhaus is the most demanding energy efficiency standard in the world. It’s focused on reducing the energy consumption of buildings as much as possible while maintaining high levels of interior comfort. Formulated in 1988 in Germany, the Passivhaus is based on exhaustive procedures in the development of the project and in the execution of the work. The latter makes it possible to guarantee that the performance of the constructed building corresponds to the theoretical design values.

The 5 basic principles of the Passivhaus

The Passivhaus standard has 5 essential principles. These 5 principles work together to guarantee the final performance of the building. For the performance to be as estimated, the Passivhaus principles have to be verified both during the design and, fundamentally, during the construction process.

1. Excellent thermal insulation

In Passivhaus, a key factor is to achieve an envelope with a very low thermal transmittance. To achieve this, it’s necessary to place thermal insulation in abundance on the walls, floor, and ceiling of the building.

2. Absence of thermal bridges

Thermal bridges are points in the envelope where the thermal transmittance is higher, producing a considerable energy loss in them. They are generally produced by a discontinuity in the insulation. Passivhaus requires minimizing thermal bridges throughout the envelope, allowing continuity of the insulation. Why? Thermal bridges also generate cold spots inside which can cause humidity, damage to materials, and loss of interior comfort.

3. High-performance carpentry

Passivhaus buildings require the use of high-performance, insulated, and airtight windows and doors. In the case of windows, two and up to three panels are used, the exterior ones being low emissivity with a chamber filled with inert gas.

All this guarantees a very low thermal transmittance, great acoustic insulation, and a reflection or maintenance of energy in the different stations.

4. Airtightness

Contrary to the belief of professionals in the construction sector, most of the energy in a building is lost by convection (movement of fluids, in this case, air) and not by conduction (heat transfer through a material or several). 

For this reason, in Passivhaus, it’s essential to guarantee the tightness to the outside air. In other words, to minimize the common infiltrations. To achieve this hermetic envelope, it must be studied during the project and verified during the works that there is a continuous air barrier in facades, roof, and the floor that guarantees water tightness.

5. Mechanical ventilation with heat recovery (VMC)

However, if we create a watertight envelope, for health reasons it will be necessary to guarantee the renewal of the indoor air. For this, in Passivhaus projects, it’s needed to incorporate a double-circuit mechanical ventilation system that, in this case, will incorporate a heat recovery system that allows minimizing energy losses. 

In certain climates, thanks to the heat recovery unit, it’s even possible to air-condition buildings using only ventilation and dispensing with specific air-conditioning systems. One of the advantages of mechanical ventilation, in a context of extreme alert for contamination, is that it allows total control of its quality with much more precision, treating it when necessary.

What are the benefits of the Passivhaus standard?

Passivhaus is a tool that allows us to check that our home meets certain performance parameters. These parameters address the annual heating and cooling consumption of the building, the maximum energy demand at a specific moment, and the volume of outside air infiltration. 

Compliance with them guarantees maximum thermal comfort and minimum energy consumption. If we add to this adequate levels of ventilation accompanied by filtration systems, we will obtain an improved air quality in our Passivhaus building.

1. Minimum energy consumption and economic savings

Passivhaus buildings consume up to 90% less energy than a building of a similar typology. This supposes a considerable economic saving in the energy bill that entails very low return on investment times.

2. Reduction of carbon emissions

This reduction in energy consumption leads to an equivalent reduction in carbon emissions. For this reason, Passivhaus buildings are the spearhead of the construction sector in the fight against climate change.

3. Maximum thermal and acoustic comfort

Given the performance of the envelope, Passivhaus buildings guarantee the minimum thermal variation in their interior throughout the day and the seasons. Likewise, the absence of thermal bridges and the presence of highly efficient glazed surfaces mean the absence of cold surfaces inside the building. 

These two characteristics provide the maximum thermal comfort of the interior. On the other hand, the super-insulated envelope itself provides maximum isolation from outside noise.

4. Maximum durability of materials

The hermetic envelope of a Passivhaus building prevents the entry of air infiltration and thus water that can be trapped inside the walls, damaging the materials and causing humidity. In turn, the absence of cold spots inside prevents surface condensation, which in turn causes damage and premature aging of the materials.

What do you think of the Passivhaus design now?