Since the focus on sustainable development in 1980s, there has been an increased awareness for well-defined green building standards worldwide. Before the advent of much of the modern green construction standards and practices, ancient European buildings had implemented many features that would be considered green today. Ancient European construction used vernacular architectural, which incorporated climate responsive designs and solar architecture. In some instances, ancient building practices have been used to improve modern building materials, such as brick and concrete. These aspects of green buildings in ancient Europe can provide ample opportunity for research today. The goal of this paper is to analyze building designs, materials, and methods used in ancient Europe and compare these practices to current green building guidelines. The scope of this paper includes examining preexisting literature on building practices in Europe before 1800AD and analyzing two case study buildings in light of LEED green building guidelines. Finally, a comparison matrix of green building features, in ancient European buildings and in modern LEED buildings, is developed. It is hoped that such comparison will provide an insight into the relevance of ancient building attributes in modern green building practices.