Deep energy retrofits of existing homes to Passive House Standard called EnerPHit. The modified standard was created by Passive House Institute to accommodate the realities encountered during a deep energy retrofit.
The Passive House Standard often cannot be feasibly achieved in older buildings due to various difficulties. Refurbishment to the EnerPHit Standard using Passive House components for all relevant structural elements in such buildings leads to extensive improvements with respect to thermal comfort, structural integrity, cost-effectiveness and energy requirements.
The EnerPHit-Standard can be achieved through compliance with the criteria of the component method (Table 2) or alternatively through compliance with the criteria of the energy demand method (Table 3). Only the criteria of one of these methods must be met. The climate zone to be used for the building's location is automatically determined on the basis of the chosen climate data set in the Passive House Planning Package (PHPP).
As a rule, the criteria mentioned in Table 2 correspond with the criteria for certified Passive House components1 . The criteria must be complied with at least as an average value for the entire building. A higher value is permissible in certain areas as long as this is compensated for by means of better thermal protection in other areas.
In addition to the criteria in Table 2 or Table 3, the general criteria in Table 4 must always be met. The EnerPHit categories Classic, Plus or Premium may be achieved depending on the renewable primary energy (PER) demand and generation of renewable energy.
For more detailed info visit: https://passiv.de/downloads/03_building_criteria_en.pdf