Every field is starting to change some of their actions in order to reduce their environmental impact, and in the hotel world seems that the message is starting to settle down, specially in the new constructions, that from the beginning are thought to be respectful with the environment.
One of the latest examples is the Hotel Barcelona 1882 (4*). It looks like it's going to be one of the leaders in hotel sustainability after gaining a LEED Gold certification, which rewards the constructions focused on energy efficiency and sustainable design. Although it's still in the building phase, the project has already received several awards as the Re Think Hotel (in the TS Media category).
To get more information on the hotel and its practices, read the following article (in Spanish): Hotel Barcelona 1882 será un referente en sostenibilidad or visit their official website: Hotel Barcelona 1882.