In March 2013 Colm Donaghy qualified as a Certified Passive House Designer and is now registered with the Passivhaus Institut, Darmstadt, Germany.
The following is an overview of the Passive house standard.
The Passive House Standard
Passivhaus or 'Passive House' is the world's fastest growing energy performance building standard. It can be used to produce any building type not just houses and certification is available for both new-build and retrofit projects.
Passive House was developed in Germany in the 1990s by Professors Bo Adamson and Wolfgang Feist and is a 'fabric first' approach to constructing low energy buildings.
The primary focus of the Passive House standard is to greatly reduce the requirement for space heating and cooling within a building, whilst creating both excellent air quality and increased comfort levels.
Reasons for building to Passive house standard
Passive house buildings achieve a 75% reduction in space heating requirements, compared to standard practice for UK and Irish new build.
Incoming air is filtered to take out pollutants and then heated or cooled to provide a constant supply of comfortable clean air that has an ideal relative humidity.
Passive house is a 'fabric first' construction type and as such doesn't rely on elaborative gadgetry to maintain comfort levels. Passive house can be built with or without the use of renewable energy components.
Passive house construction is estimated to cost approximately 10-15% more than standard construction however with running costs greatly reduced and comfort levels heightened it is money well spent.
“The heat losses of the building are reduced so much that it hardly needs any heating at all. Passive heat sources like the sun, human occupants, household appliances and the heat from the extract air cover a large part of the heating demand. The remaining heat can be provided by the supply air if the maximum heating load is less than 10W per square metre of living space. If such supply-air heating suffices as the only heat source, we call the building a Passive House.”
Prof. Dr Wolfgang Feist Head of Energy Efficient Construction/Building Physics at the University of Innsbruck, Austria and Director of the Passive House Institute, Darmstadt, Germany.
At least 75% of the heat from the exhaust air is transferred to the fresh air by means of a heat exchanger in the MHRV unit.
Excellent air tightness levels achieved through rigorous design and installation practices prevent uncontrolled air leakages from or into the building. At a pressure/de-pressure of 50 pascals no more than 0.6 of the total house volume per hour is allowed to escape/infiltrate. This greatly exceeds current building regulation standards.