Building a Passive House
Design and building a passive house is about saving as much energy as possible. They are designed carefully to efficiently use every energy source, and to store as much energy as possible. For example, such a home would be almost airtight with crazy amounts of thermal insulation. In general, it is all about ensuring the building carbon footprint is as small as possible.
In theory, a passive house may not need to be heated in the winter as it gains energy naturally via solar gain for example. But in reality most will have a very efficient heating system, but would rarely be used.
Typical Features of a Passive House
Excellent insulation is key when it comes to building a passive house. Insulation helps to keep the heat in during the cooler months, and heat out during the winter months. Passive houses have much more insulation then the average home. The idea behind a passive house is to use the least amount of resources possible when living inside it. Ideally you want the insulation to be so good that you never need to turn the heating on during the winter. This can happen when the heat gained via the sun through your windows (solar gain) stays trapped inside your house for a long period of time due to the exceptional insulation.
Eliminate any Thermal Bridges
Heat inside your home rises, and will always follow the path of least resistance to the outside. This path of least resistance is known as a thermal bridge. A passive house should be designed with minimal or no thermal bridges. This is a very challenging task as traditional homes have many thermal bridges from poorly insulation walls, cracks, gaps, etc.
To achieve superb insulating properties, the structure needs to be airtight as possible. Air will travel through the tiniest of gaps, sealing those gaps is important when building a passive house.
Having good ventilation may contradict the “airtight design” rule. Your home will build up moist air from showering, washing up, boiling wat in a pan, etc. Clever ventilation solutions need to be put in place to remove this moist air, but only in areas where it is likely to be present. Such areas would include room like the kitchen and bathroom. Also you would need to install a central ventilation system which exchanges dirty air within your home for the outside fresh air.
You might think that A rated double glazed windows is good enough for a passive house. But even these types of windows still lose to much heat. You will need the most energy efficient windows you can afford, such as triple glazed windows rated A+ or more.