This paper discusses the concept and significance of zero energy buildings, design consideration
and examines the potential of achieving zero energy target by retrofitting an existing building to
maximize energy efficiency and utilize renewable energy sources. Center of the Excellency for
Research & Development of Biofuel Technology is chosen as an existing case study to convert it to
zero energy by calculating its real energy consumption, simulating its performance using designbuilder
program, applying environmental strategies on it and examining its role in improving the
building energy efficiency and therefore reaching to zero energy building.