One of Innsbruck University’s buildings in Austria has been certified as the largest structure retrofitted to Passive House’s EnerPhit standard.

The facility was originally built in 1968 and is currently used by the faculty of technical sciences. The university worked with the Passive House Institute (PHI) to re-create the eight-storey building to achieve the certification. The extensive renovation to improve the energy efficiency of the building only cost a moderate additional amount.

The refurbishments demonstrate energy-saving potential available for the built environment. The building envelope and building services were overhauled, which improved occupant comfort. The façade has thermal protection and air openings to bring in fresh air, and it automatically controls passive cooling at night. The heating demand reduced from 180 kWh/m²a to 21 kWh/m²a.


The EnerPHit Standard, introduced by the Passive House Institute, is specially tailored to the particularities of retrofit projects; depending on the initial situation, the solutions developed for new Passive House constructions cannot always be applied on a one-to-one basis. Still, the principles of the Passive House Standard are economically expedient even in the case of refurbishments, above all the consistent use of Passive House components.