The purpose of this research paper is to determine the heat conductivity of a granular heat insulation material made of coniferous greenery (fine twigs and needles), and the suitability of the material for application as heat insulation. In order to achieve the objective, a three-factor experiment plan was developed, and 11 samples produced. The thermal conductivity coefficient, moisture content, and density of the samples was determined. A full analysis of the experiment plan was compiled on the basis of the obtained results. The analysis results suggest that size composition, density, and tree species affect the thermal conductivity of the material. It was discovered that smaller spruce greenery insulation material pellets have a smaller thermal conductivity coefficient, which indicates a better capacity for retaining heat