Building diagnostics is the process of inspecting and analyzing the performance of buildings in order to identify potential problems and develop solutions to improve their energy efficiency and overall functioning. This process typically involves a combination of visual inspections, energy audits, and data analysis to evaluate a building's systems and components, such as insulation, mechanical equipment, and lighting. The goal of diagnostics is to identify areas of improvement, prioritize solutions, and develop an action plan to maximize the potential of the building.