A study of energy performance in 19 Government Offices in Hong Kong has been carried out. The characteristics of Government Offices, difficulties and results in assessing their building energy performance are discussed and reported. An average Energy Use index based on unit floor area has been derived for the Government Offices using energy consumption data in the past three years. A number of factors that are likely affect the energy use in buildings, such as year of construction and total gross floor area are reviewed. Energy management opportunities are identified and proposed after carrying out energy audit to the Government Offices. Operational practices to improve energy performance are also recommended. (C) 2008 Elsevier B.V. All rights reserved.