Engineering demand parameters such as displacements and accelerations are critical for structural integrity and safety assessment of buildings during and after earthquakes. This paper presents the design and architecture of a prototype vibration system based on the Internet of Things for seismic structural health monitoring of buildings. The prototype comprises two sensor nodes that have an MPU6050 triaxial accelerometer with capacitive MEMS technology, a NodeMCU v3 ESP8266 microcontroller, and a power and recharging circuit for a 6800 mAh rechargeable battery. The sensor node transmits the collected data using the MQTT protocol. The prototype is calibrated using an Accelerometer, ICP®, Seismic Model 393B04 standard instrument. A real-time visualization platform of the acceleration transmitted by the sensor node is developed for remote monitoring. In addition, the collected data is processed to obtain the building response regarding lateral displacements. Schemes such as baseline correction, filtering, and Fourier transform are presented. The prototype monitoring system is installed in the Universidad de las Fuerzas Armadas ESPE administrative building, Sangolquí-Ecuador. Also, the results determined a 1.35 Hz natural frequency and a 0.74 s fundamental period of vibration.