About Passive Houses
Credit. Green Match
When planning to build a house, we obviously pay close attention to factors such as costs, architectural design, as well as how comfortable and how functional it will be. But more and more often we find ourselves thinking about energy efficiency. If we want to have a house that looks good, is comfortable and highly energy efficient, we might want to consider building or transforming our current house into a passive house. But what exactly is a passive house? A passive house is a building standard that is affordable, comfortable, and at the same time, energy efficient and environmentally friendly. This article will provide you with information on how you should proceed regarding building a passive house, the costs associated with construction, and how you can benefit from a passive house, as well as many other useful tips.
What Is a Passive House
A passive house is a concept that originated from Germany, where it’s known as Passivhaus. It is important to note that a passive house is not a brand name, but a construction concept that can be applied by anyone—commercial buildings as well as residential houses. A passive house is built so that it is very energy efficient and comfortable at the same time without using a traditional heating system or active cooling. The passive house uses passive heat sources—the energy of the sun, the heat from running household appliances, and the extracted air—in order to cover most of the heating demand. The remaining energy needs in a passive house should be supplied by renewable energy sources, such as solar panels or heat pumps. The active utilisation of this existing energy is one of the main characteristics associated with a passive house. Passive houses optimise thermal gain, at the same time minimise thermal losses. By using existing temperature, the required heating energy of a passive house is 90% lower than the energy needed for a conventional home.
Requirements for a Passive House
There are certain specifications that a house needs to fulfil in order to be considered a passive house. There are three basic requirements for a passive house:
- a passive house needs to have heating demands lower than 15 kWh per square meter annually (kWh/m²a).
- a passive house needs to have primary energy demands (such as warm water, heating, house appliances) lower than 120 kWh/m²a.
- a passive house must pass a pressure test and the pressure must be limited to 50 Pascals with the pressure differential not exceeding 0.6 times a room’s volume per hour (n50 < 0.6 h-1).
In order for a passive house to be able to have such low energy demands, it needs to be built in a certain way. A passive house needs a high level of insulation, ‘thermal bridge free’ construction (a thermal bridge is heat transferred through a poorly insulated part of a wall), airtight windows and doors, a mechanical ventilation system with heat recovery and heat efficiency, and it needs to make use of passive solar gains. Moreover, a passive house should also have low energy appliances and energy-efficient lights.
Why Build a Passive House?
By investing in a passive house, you can benefit from reduced heating bills, and at the same time, have a positive impact on the environment. A passive house is a sustainable construction that provides you with a 75% reduction in space heating requirements when compared to traditional households. Along with savings on your heating bills, by building a passive house you will not be using fossil fuels and therefore reduce carbon dioxide emissions. A passive house provides you with an evenly warm and constant climate.