The Sant Gregori School in Barcelona was built in 1972 in Collserola. The original project was laid out on terraces of the land, staggering the slabs. The integration of its section is attractive, as well as the fluidity of its interior, but it currently has serious accessibility and evacuation difficulties, a lack of facilities suitable to current standards and, in addition, it is a school that lacks pre-school education (3 to 6 years).

Therefore, the assignment focused on the reform, improvement and expansion of the facilities of the current teaching centre, and on moving the children's classrooms, currently in Arimón Street. The expansion foresees the construction of an underground car park, 6 classrooms for the pre-school cycle (3 to 6 years old), 6 additional primary classrooms and a music school that will equip the centre with a new multipurpose room (gymnastics-shows) with a capacity of up to 300 people.

The starting urban planning requirements were:

- Set back the building (to not create a façade on Carles Riba Street).
- Unitary intervention, not fragmented.
- Occupy the natural space of the rest of the plot as little as possible.
-To not extend to the high elevations of the plot.

In addition, we add that the intervention should be minimal in appearance; it would be an operation of occupying voids, emptying and filling again, replacing floors in poor condition, creating multipurpose spaces, using the roofs as playing areas that allow children to be separated by ages.

The school had a natural outdoor reception area with 3 pine trees that we set out to preserve and enhance. Around this courtyard and replacing the first terrace on which the school is located, we have built a new semi-underground administration (control and reception) which allows connecting the old building from street level with a lift. To the east, a multipurpose room (sports and entertainment) with a cover that is a basketball court. This layout is closed to the west with a grandstand-staircase that creates an agora, an outdoor public space covered by the three pines, which connects to the stage of the multipurpose room thanks to a large sliding door. Therefore, the spaces are linked, and the stage can pivot and serve inside or outside the agora.

The result is a new welcoming space where parents or children can wait, play or perform shows. It is a space that is not bounded by walls but continues towards the interior of the building, giving it greater depth especially in the afternoon with the illuminated administration.

The rest of the volumes are placed to the west, restoring the profile of the excavated mountain, receding and staggered, creating playing terraces and connecting to the old school to facilitate its evacuation. Children's classrooms on the ground floor, primary school on the first floor and music school on floors 2 and 3, a dislocated volume of two floors that is placed over the kindergarten and primary classrooms, covered in anthracite Zinc. At first floor level, the new roofs are finished with green Composan, connecting all the spaces longitudinally with great fluidity.

The building has obtained an "A" energy rating. The entire face exposed to the south is protected by flights or by a lattice of pine wood that protects the classrooms from direct sunlight. In the same way, the basketball court above the multipurpose room is surrounded by Rivisa galvanised mesh through which climbing plants will climb.

The intervention should be minimal in appearance, it should be an operation of filling holes, emptying and filling them again, of replacing terraces, creating multipurpose spaces, using decks as playing spaces.

The school has a natural outdoor reception area with 3 pine trees that we set out to preserve and enhance. Around this courtyard and replacing the first terrace on which the school is located, we built a new semi-underground administration (control and reception) which serves to connect, by elevator, the old building from street level. To the east, there is a multipurpose room (sports and shows) with a cover that is a basketball court. This arrangement is closed to the west with a step-staircase that creates an agora, an outdoor public space covered by the three pines, which connects to the stage of the multipurpose room thanks to a large sliding door. Therefore, the spaces are linked, and the stage can pivot and serve both inside and outside the agora.

The result is a new outdoor reception space where parents or children can wait, play or perform shows. It is a space that is not bounded by walls but continues towards the interior of the building giving it greater depth, especially in the afternoon with the illuminated administration.

The building has obtained an "A" energy rating.