Around 40% of total energy consumption is in household use, some 70% of this number is
due to heating/cooling. In this time of great price increases of energy sources, global
warming and greenhouse effect, energy efficiency and sustainable construction along with
the possibility of using renewable energy sources are becoming a priority when contemporary
construction and the energy industry are considered. A fundamental principle of improving
energy efficiency of buildings is to optimize the thermal insulation of the external building
envelope and to reduce the thermal bridging. Low energy houses are a great step forward in
achieving this goal. This paper investigates the potential for energy and CO2 emissions
reduction when a passive house space heating standard of 15 kWh/m2
is applied to new built
houses in Croatia. The calculations are based on a computer model representing national
standards and the best European practice in the passive house construction.