It all started in the 1970s and 1980s. The population began to experience a change in awareness of environmental problems and the need to address the energy crisis.
Germany. 1990. Kranichstein Passive House. This was the scenario that kick-started the construction of Passive Houses or Passivhaus with the aim of building highly efficient houses that could maintain a comfortable indoor environment without relying on heating or cooling systems.
In today’s article you will find all the details about this new trend that has re-emerged in the construction sector.
What is a passive house or passivhaus?
We talk about a house being passive when it has been built following the principles of passive architecture: thermal insulation, controlled ventilation, air tightness, solar protection and the elimination of thermal bridges.
The main objective of these constructions is to minimise energy consumption and associated carbon emissions, while creating a healthy and comfortable indoor environment for the occupants.
By drastically reducing the energy demand for heating and cooling, these homes can achieve up to 10 times greater energy efficiency than a conventional house.
How to get a passive house
As mentioned above, in order to be able to say that you have a passivhaus, you have to comply with the principles of passive architecture. To do so, here are the main steps to convert your house into a passive house:
Thermal insulator
One factor that plays a crucial role in the energy efficiency of a passive house is the thermal insulation.
Its main purpose is to reduce heat loss in winter and to avoid excessive heat in hot periods.
To achieve this, it is important to insulate walls, ceilings and floors. And what are the best materials?
- Polyurethane foam
- Cellulose fibre
- Extruded polystyrene (XPS) or expanded polystyrene (EPS) insulation panels.
In addition, install high quality windows and doors with double or triple glazing and good insulating frames to minimise heat loss or unwanted heat gain.
Controlled ventilation.
Installing a mechanical ventilation system with heat recovery (MHRV or HRV) is essential to ensure a healthy, comfortable and highly energy-efficient indoor environment.
Its main purpose is to ensure a continuous flow of fresh air into the home, while extracting stale and moisture-laden air.
Air tightness.
It prevents infiltration and uncontrolled air leakage from the inside to the outside or vice versa. Air tightness in passive houses is achieved through various strategies and techniques:
- Seal cracks and joints
- Use materials that are resistant to the passage of air.
- Perform various airtightness tests. The most common is known as the blower door (pressure test). This involves placing a fan in an opening in the enclosure and creating a pressure differential, which allows air leakage to be measured and ensures that it is within the established limits.
The importance of orientation.
Building design should take into account solar orientation to maximise or minimise sun exposure depending on the season.
- Northern hemisphere: it is advisable to orientate windows to the south to maximise solar light and heat during the winter.
- Southern hemisphere: it is ideal to position most windows to the north to maximise sunlight and warmth in winter.
Renewable energies
If possible, consider installing renewable energy systems, such as solar panels or wind power, to cover part or all of your home’s energy demand.
Using solar energy can save you more than 50% on your electricity bill, which is equivalent to around €700 per year in euros.
Although converting a house to Passivhaus may require a higher initial investment, you will be grateful for all the effort in the future. Your life will improve and you will notice the savings.
Today, Passive Houses continue to be a cutting-edge solution for constructing highly energy-efficient buildings with a lower environmental impact and greater indoor comfort for their owners.
