This paper compares the sustainability aspects of three family houses according to the Slovak building environmental assessment system (BEAS). Various categories of family houses were evaluated, including site selection, project planning, building construction, indoor environment, energy performance, and water and waste management. Based on the results, Family Houses 3 and 2 are certified as BEAS SILVER, with scores of 2.46 and 2.01, respectively. Family House 1 is certified as BEAS BRONZE, with an overall score of 1.44. The results show, not only the importance of the site in terms of availability, connectivity to the network and the potential to use renewable energy sources, but also the importance of the design and construction of the building, including the application of environmentally friendly building materials, ensuring the quality of the indoor environment and the energy efficiency of the building. The aims of this study were to highlight the current trend in the design and construction of low-rise residential family houses in Slovakia and to identify gaps in the design and construction of key sustainability aspects through the existing building environmental assessment system. In the future, many low-rise residential family houses will be assessed to modify and validate BEAS.