In the present research there is investigated straw–clay material used in wall construction, its load bearing and heat insulation properties. The main aim of this study was getting optimal straw–clay construction material, which could be used in load bearing external wall construction of one–storey house. The effectiveness of different kind of straw and clay proportions in construction material was determined by compression and thermal conductivity tests. To show the effectiveness of straw–clay material in load bearing external walls, there were made a specific model of one–storey house in finite element analysis program Ansys. As a result of this study it was determined that straw–clay block construction material in right proportions can be used in one–storey house load bearing external walls with sufficient compressive strength and thermal resistance. Also from all the calculations there were made a conclusion, that the main limitation in those kind of walls are deformations.