Egypt's consumption of non-renewable energy sources led to a shortage of its natural reserves of oil, natural gas and
coal, and the depletion of available resources without taking into account the right of future generations. Also, energy
production from these sources causes environmental pollution and as a result, the World Health Organization has
determined that the proportion of pollution in Egypt exceeds Three times the global rates of environmental pollution,
and therefore we should go to the use of renewable energy sources. The old existing office buildings were chosen
because they represent a large percentage compared to new construction, and suffer from energy consumption during
work days ,so this research paper aims to identify weakness points in the development of old office buildings in
Egypt, it's important to develop the old buildings because of their economic and environmental benefits, they are less
expensive than new buildings in terms of economic cost and energy consumption and on the other hand it helps to
extend the building life. This study follows the inductive methodology by studying the strategies of some countries
to improve and develop energy efficiency in the old office buildings through the renewable energy's application, And
follow the analytical methodology by analysing global and local office buildings that have been developed and
improve its energy efficiency.