It is not always possible to achieve the Passive House Standard (new constructions) for refurbishments of existing buildings, even with adequate funds. For this reason, the PHI has developed the “EnerPHit – Quality-Approved Energy Retrofit with Passive House Components” Certificate.
Significant energy savings of between 75 and 90 % can be achieved even in existing buildings, for which the following measures have proved to be particularly effective:
- improved thermal insulation (based on the principle: if it has to be done, do it right)
- considerably improved airtightness
- use of very good quality windows (there is no reason why Passive-House-suitable windows should not be used whenever the opportunity arises)
- ventilation with highly efficient heat recovery (again, Passive-House-suitable systems are very recommendable)
- efficient heat generation
- use of renewable energy sources
These are exactly the same measures that have proved to be successful in new constructions. A number of examples demonstrating the application of high-efficiency technology in existing buildings have become available in the meantime. The Passive House Institute has advised on the implementation of several projects and carries out measurements in modernised buildings.
To know more about the EnerPHit-Standard you can also visit the corresponding section in the Passive House Institute's website: "EnerPHit" - New PHI-Certificate for Refurbishment of existing buildings