INTRODUCTION: One of the most significant challenges in the development of applications and AAL (Ambient Assisted Living) platforms is the interoperability between the various systems that compose the AAL platform. However, one solution would be to use the Internet of Things (IoT) technologies and standards to address requirements that, such as interoperability, are common to both domains. OBJECTIVES: To propose a model of sensor data representation and an IoT-based architecture in an AAL context, which reduces the impact of interoperability without overwhelming the overall system performance. METHODS: We have developed an AAL platform using pub/sub communication. A Raspberry Pi acts as a gateway among sensors, the RabbitMQ platform, and the AAL applications. We have developed a data representation model, based on existing AAL models, and a Protocol Bufferscommunication strategy that considers platform independence and spatial decoupling to address interoperability. RESULTS: We implemented and evaluated our model with the integration of two AAL applications installed in a Living Lab, which uses distinct devices, data formats, and programming languages. Then, we simulated a daily situation and analyzed the results regarding the overall performance. Results showed our solution presents a faster average response time than without its adoption. Also, our solution performed more stable behaviour.