What is Passive House?
What is Passive House? Passive House is a term that we are starting to see emerge on the newspapers, hear on the radio and people around us seem to mention about it more and more.
In recent years, Passive House has gained the momentum in the New Zealand building industry and housing market.
In this blog we will introduce you to what Passive House is.
Brief Overview
Passive House is a world leading standard for energy efficiency in the building. The focus is on the building fabric, which is designed to be well insulated, airtight, thermal bridge free, which at the same time provides comfort by utilising mechanical heat recovery ventilation.
It was discovered by Dr. Wolfgang Feist, a German physicist back in 1988 in response to oil embargo.
Passive House is not only limited to residential builds. Over on the other side of the globe, especially in Europe, the Europe Passive House Standard was implemented to office buildings, commercial buildings and even school buildings.
The Passive House Standard
You may wonder, what is the Passive House Standard?
In this blog, I will just give you an overview of the Passive House standard requirements. In future blogs, I will dive further into the details of each requirement and component that would come together to achieve the Passive House standard. Let’s go through this journey together.
The requirements of Passive House certification criteria is as follow:
• Heating energy demand : less than or equal to 15kWh/(m2a)
• Building Heating load: less than or equal to 10W/m2
• Airtightness: less than or equal to 0.6/h
1. Heating Energy Demand and Building Heating Load
For example, for a house to achieve a heating requirements of Passive House, you need to either comply with Heating Energy Demand or Building Heating Load. Let’s say a house has a treated floor area of 150m2. For this house to achieve the heating requirements, it must not consume energy exceeding 2250kWh/a or 1500W. For airtightness requirements, suppose this house has an air volume of 375m3, so then the air change per hour must not exceed 225m3/h.
2. Thermal Bridge Free and Heat Recovery Ventilation
Passive House focuses a lot on the comfort and health of the dweller by employing thermal bridge free strategy and utilising the heat recovery ventilation system. A Passive House can keep the indoor temperature at 20-25Celcius all year round with fresh air supply 24/7.
By employing thermal bridge free strategy, Passive House eliminates the risk of having mould growing inside your house. It not only achieves the highest standard of comfort, but also reaps the benefit of healthy indoor air quality.
3. Airtightness
Passive House also needs to be airtight to stop losing heat out through air infiltration.
Imagine wearing a puffy jacket without zipping it up. Cold air still can blow in to make you feel cold or discomfort. The same principle applies here. If the building is insulated well but there are holes everywhere, cold air still has influence inside the building and can cause the losing of heat and discomfort for the dweller.
As NZ building industry progresses on, we start to learn more and become inspired to build better buildings for the health and comfort of the dweller. At the same time, we also respond to the rising cost of energy and endeavour to reduce the amount of carbon emission.
Your Choice Investment
By calling a house a Passive House means that that house has gone through not only a very strict design process, but also a very rigorous certification checking process so that you can have the assurance that your home is of prime quality building performance. This could be your choice of investment. By investing in a Passive House, you will reap comfort, health, reduce energy cost and consumption and good for the earth for years to come.
