Passive houses combine the latest knowledge and experience in the area of design and construction. They emerged recently as a result of numerous researches in the field of energy efficiency in buildings and people’s demands for favourable housing conditions. The standard for passive building construction introduced specific construction criteria, which significantly exceed the general standards and construction regulations.

The passive house currently represents the closest approximation to the best energy input ratio, but it still places a minimal burden on the environment and the quality of life that modern man expects from his house. In order to differentiate between ordinary objects and these buildings, there are rules, criteria, which are significantly stricter than the construction criteria of the current legislation. For passive houses, the following criteria apply: energy consumption for heating £ 15 kWh/m2a, electricity consumption £ 18 kWh/m2a, total primary energy consumption of £ 120 kWh/m2a. Heat losses must not exceed 10 W/m2 per heated surface, and measured uncontrolled air exchange n50 £ 0.6 h.


To achieve those high criteria and thus categorize passive houses as passive buildings, it is necessary to fully consider numerous natural laws, properties of embedded materials, good planning and especially strong construction. When planning and calculating the energy balance of a building, we use the PHPP program, which consistently takes into account all internal and external sources, location, position and design of the building and the outer envelope of the building.

The building envelope counts as the most important part of the building as it saves a major part of the overall energy loss. Passive houses have at least a 10-times better insulation as the average 30-year old house and consequently much lower power consumption.
As mentioned above, the outer envelope of the building is one of the major elements of the passive house. Heat transfer of an opaque outer envelope without thermal bridges must reach U £ 0.15 W/m2K, and window glazing including frames U £ 0.8 W/m2K. These values can be achieved on the basis of a well-performed construction of the external envelope with minimal thermal bridges, an appropriate thickness of thermal insulation and good sealing of all joints, especially windows.
Rihter Company d.o.o. is a member of the Passive House Consortium, which was established in 2008. Apart from the Faculty of Architecture, the founding members are also enterprises whose activities offer the possibility for the construction of passive houses or will do so in the near future. For further information on this topic please consult the website http://www.fa.uni-lj.si/konzorcijph