 Existing buildings account for approximately 40% of global primary energy consumption, according to data from the International Energy Agency, IEA. In order to reduce this figure, the European Union adopted the energy performance of buildings directive, which mandated member states to reduce their GHG emissions by 20% compared to 1990 levels, while increasing the use of renewable energy sources by 20%. Additionally, the directive required member states to ensure that all new buildings in the EU must consume nearly zero energy after 2020. Furthermore, the directive stipulated that all new buildings should be constructed using lightweight concrete blocks or limesand bricks in order to improve energy efficiency. In Slovakia, there is abundant timber available, making it ideal to construct wooden family houses. However, this type of construction is often perceived negatively due to outdated preconceptions. This paper evaluated the results of two wooden family houses, constructed in 2000 and 2018 respectively, in terms of low energy construction and sustainable development principles. The first house was built under valid thermal technical standards, while the second was a newly constructed passive house. This article was offered by Pavel Duricka, Silvia Baterova, and Radoslav Ponekl. We are article.tv, links in the description below.