This research was conducted in response to concerns about room comfort and the Sick Building Syndrome (SBS) phenomenon. The focus of this study was to examine the effect of photobioreactor (PBR) based algae facade on the room microclimate and growth of Aspergillus niger . A glass simulation chamber resembling the letter “U” with a size of 40 cm long, 40 cm wide, and 40 cm high has been used for the experiment. Twenty samples of Aspergillus niger were tested for 11 days in four simulation chambers and were given different treatments, two rooms were installed with PBR and the other two rooms were not installed PBR (control). The room with PBR had a relatively lower temperature and humidity in the peak phase with a difference of 4.3°C and 5.5% RH compared to the control room. In addition, three out of ten molds in the PBR chamber had a growth rate of about 0.94 cm ² /day and the spore production of 1.9×10 ⁴ CFU/ml. Meanwhile, seven out of ten molds in the control room had a growth rate of 1.4 cm ² /day and an average spore production of 5.4×10 ⁴ CFU/ml. These results indicate that the algae facade is able to improve the microclimate of the room and suppress the growth rate of Aspergillus niger . mold in buildings.