The production of conventional bricks causes environmental problems and the depletion of natural resources. Besides, a huge amount of bottom ash from the Nghi Son coal power plant is released day by day, and it needs to be recycled. To overcome these issues, this study investigated the recycling of bottom ash as a fine aggregate to replace natural chippings for the production of unfired building bricks instead of fired-clay bricks. All brick mixtures were designed with a constant water-to-binder ratio of 0.35. The bottom ash was used to replace 0%, 30%, 50%, 70%, 85%, and 100% chippings. The properties of unfired building bricks including visible defects, unit weight, compressive strength, water absorption, and water permeability, were tested following TCVN 6477-2016. Test results indicate that all brick samples show a nice appearance without any visible defects. The color of bricks was darker and the surface of bricks was smoother with the inclusion of more bottom ash. The unit weight and compressive strength of bricks decreased, while water absorption and water permeability of bricks increased with increasing bottom ash content. All unfired building bricks in this study showed good quality, as stipulated by TCVN 6477-2016, with compressive strength of higher than 15 MPa, water absorption rate and water permeability of below 14% and 16 L/m2h, respectively.