What is a Passivhaus?

In our first post of the series, we are going to be exploring what a Passivhaus is and how it originated.  

A Passivhaus is a building in which thermal comfort can be achieved solely by post-heating or post-cooling the fresh air flow required for a good indoor air quality, without the need for additional recirculation of air.”

Passivhaus Institute (PHI) 

Simply put, it is an energy efficiency standard for buildings which is both a world leading concept in energy efficiency; but also aims to promote comfortable, environmentally friendly, and affordable homes and buildings. 

Driven by air quality and comfort, the design will make use of the ‘passive’ influences on a building including sunshine, shade and ventilation. As well as helping to maintain a comfortable temperature in the home, it uses much less energy than a traditional home. And it is not just homes either. There have been schools, kindergartens, and a supermarket all built according to Passivhaus standards.  

The concept was coined by researchers in southwest Germany in the early 1990s and in 1996 Wolfgang Feist founded the Passivhaus Institute. The Passivhaus Institute is a research institute dedicated to developing the Passivhaus concept and encouraging countries around the world to adopt its standards and technology.

To achieve the certification, you must use the specific planning system, which allows you to adjust your design until your property reaches the required energy efficient standard. 

Achieving the Passivhaus Standard in the UK typically involves: 

  • Accurate design modelling using the passive house planning package (PHPP) 
  • Very high levels of insulation 
  • Extremely high-performance windows with insulated frames 
  • Airtight building fabric 
  • ‘Thermal bridge free’ construction 
  • A mechanical ventilation system with highly efficient heat recovery 

The actual construction methods of Passivhaus buildings will vary but they will all have some of these features in common. Next week we will be looking more in-depth at the design of a Passivhaus and what makes it so energy efficient.