Indoor air quality (IAQ) has a substantial impact on public health. Since the beginning of the COVID-19 pandemic, more employees have worked remotely from home to minimize in-person contacts. This pilot study aims to measure the difference in workplace IAQ before and during the pandemic and its impact on employees’ health. The levels of fine particulate matter (PM_2.5) and total volatile organic chemicals (tVOC) were measured in the employees’ offices before the COVID-19 pandemic and at homes while working from home during the pandemic using Foobot air monitors. The frequencies of six sick building syndrome (SBS) symptoms were evaluated at each period of monitoring. The result showed PM_2.5 levels in households while working from home were significantly higher than in offices while working at the office for all participants (p < 0.05). The PM_2.5 levels in all households exceeded the health-based annual mean standard (12 µg/m³), whereas 90% of offices were in compliance. The tVOC levels were all below the standard (500 µg/m³). We also found a higher frequency of SBS symptoms were observed while working from home as the IAQ was worse at home. This study suggested that working from home might have a detrimental health impact due to poor IAQ and providing interventions to remote employees should be considered.