Due to the COVID-19 pandemic, home-office has turned to be a common practice in many companies to limit physical contact to reduce the rate of infections in the workplace. To quantify office workers’ ADLs, this work demonstrates unobtrusive monitoring of activities of daily living (ADLs) of an office worker in a home-office environment with three low-cost sensors: an accelerometer and two light sensors. We extract four elementary events: distinct and fain chair movement, monitor, and fridge usage, from which we derived seven ADLs using predefined rules. This simple system can support the quantification of ADLs of home-office workers.