Green building is a process of creating buildings in a sustainable way by using processes which are environmentally friendly and resource efficient over the life of the building. The development of green building is driven by awareness of climate change and human impact on environmental pollution and tendency to increase quality of life. Since the construction industry has a major impact on the use of natural resources and the creation of polluted environments, it has been necessary to introduce changes over conventional construction. The main goal of green building is to extend the lifetime of the buildings and to maximize the creation of healthy and comfortable indoor environment. This paper describes some aspects that green building is trying to improve, such as increasing energy efficiency, reducing water consumption, and using eco-friendly materials. In order to encourage and reward sustainable construction, various certification systems have been developed that evaluate the level of sustainability of a building and assign it an appropriate level of certification. Also, this paper describes and compares LEED, BREEAM and DGNB systems as the most widely used systems for assessing the conformity of buildings with the environment, and gives examples of buildings in Croatia and worldwide that have been awarded one of the aforementioned certificates.