The current trend in building sector approaches involves energy management and local energy communities. These aspects heavily rely on data sourced from sensor networks. However, the data collection mechanisms utilize communication networks, introducing inherent risks in data manipulation. To mitigate these risks, blockchain-based procedures offer benefits by ensuring trust, confidence, and security in data transmission. This work introduces a secure and trustworthy framework based on smart contract development. The framework aims to provide a proof of existence mechanism in data monitoring. A real test scenario serves as a proof of concept, utilizing actual data to demonstrate that the smart contract enhances confidence by ensuring data coherence.