Nowadays, for environmental reasons, the demand for bio-based building materials is increasing. The number of studies focusing on earth building bricks with addition of plant aggregates is growing. In this study, barley and lavender straws were considered as bioaggregates in an earth matrix. Their characterization revealed distinct shape, size and porosity. Composites including 3% and 6% by mass of each bioaggregates were then elaborated. Their performances were investigated and compared in terms of mechanical and thermal properties, durability of the composite materials and resistance to fungal growth. The mixture with 3% of lavender straw showed satisfactory durability results while barley straw brought better thermal properties.