The workshop will focus on state of the art in energy efficiency and renewable energy production in buildings, and next steps to accelerate the energy transition until 2030. The discussions will be about challenges with: 1) Renewable energy and storage 2) Balance between energy efficiency measures in renovations and new buildings and consumption-based CO2 emissions 3) Energy Community and Microgrids  4) Positive Energy Districts  5) AI and Digital Twin as a tool to reduce energy use.