The main idea is to have a kit so that we can measure the electricity consumption, the temperature and the humidity in a building. The system should be scalable and be capable of enhancement with an array of different sensors (water and gas consumption, solar production, etc).
We could also think of adding a weather station.
The most appropriate solution for enabling us to do this is the OpenEnergyMonitor project, an end-to-end open-source energy monitoring system.
Here is the documentation of the project.