The construction industry consumes a large portion of the raw materials and generates an enormous amount of solid waste annually especially in installing the building envelope. Despite the positive impact of the building envelope on achieving the economic development goals of the countries, it has been proven that the waste generated from the construction and installation processes has a significant negative impact on the economy and the environment, which led to a waste of 10% of the cost of project materials according to global statistics in 2010. This paper aims to (1) identify the causes and impacts of wasted materials, (2) present the results of the field study conducted by the authors to investigate the causes of material waste in the implementation of building envelopes in Egypt, (3) identify the most important, sub-factors and causes of material waste in the implementation of building envelopes in Egypt. (4) Based on expert   s' opinions, recommendations are made to avoid wasting materials in implementing building envelopes in Egypt.