Importance of Enerphit Standard in Passivhaus Refurbishing Constructions

The usage of Passive House components in the refurbishment of any existing building brings many extensive improvements like thermal comfort, economic efficiency, absence of structural damage and climate protection. Such projects have caused a great reduction in the heat energy demand and have achieved this objective by 90%.

Achieving the Passive House Standard in refurbishing the existing buildings is not a realistic goal. Reason being, the basement walls are remained avoidable thermal bridges even after refurbishment. To attain such refurbishing, Passivhaus Institute has established EnerPHit for certified energy retrofits with Passive House Components. This certification needs a maximum heating demand of 25 kWh/(m²a) or alternatively the consistent use of Passive House components in accordance with the requirements for PHI certification of components. PHPP calculates the heating demand and the quality of the thermal protection.

If the certification criteria for a Passivhaus are met while refurbishing, then the building can be certified for a "Quality-Approved Passive House" based on the same criteria as for new buildings.

However, sometimes it is really difficult to achieve the Passivhaus standard for older buildings with reasonable effort. The use of Passivhaus technology for all relevant building components in existing buildings does lead to considerable improvement in respect of thermal comfort, structural protection, cost-effectiveness and energy requirements.

Those buildings that have been refurbished using Passivhaus components and largely with exterior wall insulation can be certified to the EnerPHit standard as a proof of quality assurance and to obtain the specific energy values.

The designation EnerPHit+i is used if more than 25 % of the opaque exterior wall surface has interior insulation. It will be likely that moisture analysis will be needed where opaque elements are insulated internally.

Here is the standard relaxed certification criteria indicated below for Passivhaus Construction under Enerphit standard:

Criteria                                  Passivhaus                          EnerPHit

Specific Heat Demand        ≤ 15 kWh/m².yr                  ≤ 25 kWh/m².yr

Primary Energy Demand    ≤ 120 kWh/m².yr               ≤ 120 kWh/m².yr *

Limiting Value                        n50 ≤0.6-1                        n50 ≤1.0-1

* PE ≤ 120 kWh/m².yr + ((SHD - 15 kWh/ m².yr) x1.2)