LANG consulting - Passive house lives up to its promise

Passive house lives up to its promise

Austria's first refurbishment of an existing house to passive house standard has now been granted the distinction of certified passive house by the Passivhaus Institut. This single-family home located in Pettenbach was renovated with one storey added in 2005, converting it from an uncomfortable, dark bungalow built in 1960 to a hardly recognisable state-of-the art domicile meeting passive house standard. The existing single-storey massive building was stripped down and renovated with one storey added by using a thermal envelope made of pre-fabricated timber frame elements. As a result, heating energy demand was reduced from around 280 kWh/m²a to only 15 kWh/m²a according to the values calculated in line with the Passive House Planning Package (PHPP). The photovoltaic system integrated in the facade provides roughly 60 per cent of the electricity needed to cover the heating energy demand.

Tried and tested for 8 years – the passive house lives up to its promise!
Meanwhile, actual heating, end and primary energy consumption figures over 7 years have become available, all of which are lower than calculated according to the Passive House Planning Package (PHPP).
This demonstrates impressively that it pays to provide exact dimensions using the right calculation programme from the very beginning of planning. This building already now meets all criteria of the nearly zero energy buildings directive that will be obligatory throughout the EU from 2020 on.

Building owner family Schwarz was just as pleased about the distinction of having a certified passive house as were their planners Dipl. Ing. Mathias and Ing. Günter Lang of LANG consulting.
"It simply pays to plan and build a quality-tested passive house according to the guidelines of the Passivhaus Institut Prof. Dr. Wolfgang Feist – both for new buildings and refurbishments", underlines Ing. Günter Lang of LANG consulting.

Extra costs pay off from the very first day
Systematic conversion of the house to a passive house has involved extra costs of 15 % compared to conventional refurbishment. However, the building owners also classified for receiving the highest subsidy available from the regional government. The remaining higher bank loan taken out for refurbishment was completely covered by dramatically reduced energy costs. Moreover, bank interest rates are lower than the anticipated rise in heating costs (occurred since 2005), which has turned the consistent refurbishment effort into a profitable project from the very first day on.

Maintenance costs also went down dramatically
While keeping annual service intervals for the gas heater, liquid gas tank and the chimney was mandatory in the old building and totalled more than € 400,- per year, the only thing that still needs to be done now is changing the filter regularly for € 85,- a year. Maintenance of the ventilation system as such is scheduled for next year, the first time in 9 years *), as the system has worked flawlessly until now.