The X House project aims to solve by the definition of a system, language, or even through a unique form, a number of enquiries that arise when we consider the given site: how to protect and give transcendence to an impressive pine, which is located on the top of the site and makes access to the house extremely complex from the street; how to avoid deciding between the views of the sea and those of the mountains, allowing both to be viewed in opposite directions; how to neutralize through form the presence of the adjacent buildings in order to create a feeling of isolation; how to allow quality views from both the front and the rear of the house; how to address so many requirements with a simple movement that answers all of the previous aims without prioritizing nor explicitly formulating a response to any of them. The form, a unique form, is the result of a long process of search for individual answers to each of those challenges; thus, the form is not a priori, but an effort to give a unitary response which satisfies each of these stipulations.