passivhaus

How did it all start? 

30 years ago, in Darmstadt, Germany, the first seed of the Passivhaus concept started to grow. Professor Wolfgang Feist’s main motivation was climate protection. It was already clear that fossil-based energy sources are limited and that the production and operation of these sources leads to extremely high CO2 emissions. Together with the Swedish engineer Bo Adamson, they searched for passive measures that kept house temperatures warm and stable, experimenting while building what was to become the first Passivhause.

design your HOUSE - passivhaus

How does it work?

Glad you asked. Hilit Einav has been a Certified Passive House Designer since 2020 and is here to assist you with your project.

Utilising Passive Solar and Passivhaus principals to achieve comfort and energy efficiency is part of our expertise. 

For us, the built environment is not just form and mass; it is the relationship we have with nature, terrain, and orientation. We will design your space with utmost commitment to you and the environment. Our aim is to help you achieve a beautiful, energy-efficient home.

Did you know?

In a well-insulated and airtight building, the temperatures are kept at comfortable levels all year round and therefore, the energy consumption is reduced. Planning according to the five principles of the Passivhaus Standard ensure homes are healthy inside and resilient to the extreme climate outside.

Why do Passivhaus buildings need a ventilation system? Can windows and doors be open?

We all know that constant air supply and air flow is required to maintain a healthy indoor environment. For various reasons, buildings in Australia were constructed with gaps; there was no construction code requirement setting a minimum airtightness. The air leaking through these gaps, seen as a benefit rather than an issue.

Now we know that reducing air leakage is one of the best ways to improve the thermal comfort and energy performance of a building. The Passivhaus Standard is very clear about airtightness performance, which is measured by an expert equipped to perform the blower door test. A Passivhaus building will not have gaps to allow the air to flow through its structure. Instead it will need a Mechanical Ventilation Heat Recovery (MVHR) system to allow for constant air supply and air flow.

The MVHR system is a continuous ventilation system that circulates air in a building and only requires a small amount of energy to operate. It is essentially the building’s lungs, but better, effectively maintaining high indoor air quality 24/7. It recovers heat and removes pollutants through filters, prevents dust, smoke, pollen and other allergens from entering your home, and protects it from mould and mildew, ensuring a healthy environment.

Yes, windows and doors can be opened as you wish but knowing that Passivhaus living incorporates this MVHR system means that opening your windows for clean, fresh air is not required.

What about condensation, why it occurs? why is it so bad for the building?

Cold air has lower water vapour density than warm air. When air cools down, its ability to hold moisture decreases, and so the relative humidity rises. When the relative humidity reaches 100% it reaches its dew point, and if the air continues to cool down, the moisture will condensate.

In buildings, when warm air comes into contact with a cooler surface, like glazing, the moisture in the air will start to condensate on the surface. Window or door glazing is good example because we can see it happening, and therefore we are familiar with the phenomena. However, what most of us don’t know (because we can’t see it), is that this is exactly what happens within the structure of the building.

Air diffuses from the warm side to the cool side. It travels through the building envelope and when it reaches dew point within the construction of the building itself it can affect the performance of the building, and cause problems like mould growth, mildew, corrosion, and decay of the building fabric. This is bad for the building and the ones living in it. 

So how does it work?

The Passivhaus practice is a pragmatic combination of applied building science and economics.

The building envelope is designed using PHPP software, which allows the Certified Passive House Designer to specify the combination of insulation and other components required to bring any building to the performance level that suits their climate zone and building specifics; orientation, geometry, and surrounding’s ecosystem. In a non-passivhaus building, a large portion of energy is invested in heating and cooling to create a comfortable living condition (i.e. a temperature control method which directly affects the energy bills). 

The energy sources used in passivhaus buildings do not affect the thermal efficiency of the house. A fabric-first design approach ensures that the building’s thermal performance is calculated in advance in order to reduce future reliance on energy consumption for internal comfort. Ideally, the primary energy source would be electricity, so usage of energy could be sourced from renewable energy technologies either installed on site or sourced via the existing grid. This will enable a shift away from fossil fuels and reliance on gas and coal. 

“Conservative predictions show that greenhouse gas emissions from the electricity generation network in the National Electricity Market will decrease in the coming years, while emissions from the natural gas industry are unlikely to do so, meaning that the emissions savings of electric appliances will only increase in the future.” Renew Magazine