Wireless sensor system for integration into buildings

A wireless sensor system for integration into buildings includes a plurality of light-collecting windows, a data collector, and a cloud server. Each of the light-collecting windows, corresponding individually to a pre-defined station number, comprises a solar cell module that converts solar energy to electric power, and an expandable sensor module that receives the electric power and transmits a sensing signal that carries a corresponding station number and a sensed ambient data. The data collector, within a predetermined time period, sorts out the sensed ambient data associated with the same station number while receiving the sensing signal, and then sends out a plurality of digital signals that carry the sensed ambient data associated with the same station number. The cloud server receives the digital signals, and, based on the sensed ambient data corresponding to each station number, determines the peripheral conditions around the buildings.