The aim of this project is to refurbish and enlarge of the clubhouse of the Atlétic Terrassa Hockey Club. The ATHC sports facilities are set amidst a splendid landscape directly linked to the Sant Llorenç del Munt Natural Park. Its proximity to the urban nuclei of Terrassa, Matadepera and Sabadell endows it with a strategic position of great potential. The pre-existing building, an old construction dating from 1952, is characterised by its location in the middle of a thick pine forest that creates a pleasant microclimate in which the club’s activities have unfurled. The club’s main hockey field lies right next to the building, setting up an intense interaction between different events. The pre-existing construction consists of two volumes built at two different times: the first in the form of an U that contains the bar-restaurant area and generates an outdoor public space in the form of terrace, the second a hexagonal volume with inclusive geometry that contains various meeting rooms and offices. The intervention on the building embraces three projectual strategies: 1.Substraction: The gutting of rooms inside the pre-existing building generates a new empty space with indeterminate characteristics that turns into a bigger social space. 2.Interaction: A new perimeter construction with the new rooms is developed around the emptied central space. It is defined by these rooms, which also multiply the complex’s programmatic possibilities. 3.Connection: The insertion of an interior ramp between the two pre-existing volumes activates the building’s connections with both the surroundings and the perimeter roof, which extends towards the hockey field to create a covered terrace that offers panoramic views of the facilities while serving as an ideal spot from which to watch matches. The new perimeter construction’s placement pays the utmost attention to the pre-existing trees: a house amidst pine trees. The basic elements in the development of the project and the construction of the building are glass, light and the pre-existing trees, each with the same degree of importance. The end result can only be read in terms of their interaction.