The energy performance in two administrative office buildings in Egypt is evaluated. One building is a traditional classic building while in the other building the designer consider energy efficiency and solar energy generated power contribution to the power required. The office buildings in this study has been designed with the compliance of the building regulation during their contraction time. The evaluation is done by ENERGY STAR. The main conclusions were that ENERGY STAR can be used to evaluate energy performance of office buildings in Egypt. Egyptian office buildings can compete the USA office buildings in applying energy efficiency strategies. In addition, energy efficient lighting and HVAC systems used in the new building save 19% and 64% of the energy used respectively and will save about 46% from the source energy used. In addition the GHG emissions / m2 in the new building is half that of the existing one.