In 2016 company JSC Energy Advice accomplished detailed audit of Lithuania’s central bank building systems (Gedimino pr. 6, Totorių str. 2, 4 and Žirmūnų str. 151, Vilnius). Audit included comprehensive analysis of electrical, heating and air conditioning systems. Provided results consist of full electrical network one-line diagrams, analysis of heating, hot water and air conditioning systems condition, calculation of reliability factors and probabilities of uninterruptible power supply failure for first category electrical loads. Proposed electrical and heating networks optimization techniques and recommended solutions for problems are sufficiently justified and explained.