The tourism industry is not only the largest industry in the world, but also the largest source of revenue for Greece. However, due to the materialistic era in which we live, mass tourism is promoted and this industry is responsible for about 5% of global emissions of greenhouse gases. In addition, the sensitive ecosystems of tourist areas (islands, habitats, etc.) are degraded, gradually depleting natural resources and eroding the natural environment, thus significantly hampering the proper functioning of the ecosystem.

With the revision of the policy of the existing tourism model, it is considered necessary to move to a more sustainable one, with the promotion of different categories of tourism, environmentally friendly, such as ecotourism and agrotourism. Hotel facilities play an important role, as they should follow some guidelines set by sustainability certifications, in order to be built from scratch or upgraded with the aim of almost zero burden on the environment.

However, despite efforts to promote sustainable tourism, in Greece this model is not fully supported due to the incomplete information given to entrepreneurs and tourists, with the result that out of 10.052 hotels and over 70.000 rooms and accommodations in the country, only 460 have been certified.

The aim of this thesis is to list the effects of the conventional tourism model and to inform, based on existing examples, about the alternative modes of operation of the facilities, and information from the certification systems, about the requirements defined by each, as well as the levels at which they are divided, in order to encourage the transition of hotels towards sustainability.