Taking energy efficiency and almost zero energy consumption as a premise, SUMO Arquitectes, extensively refurbishes the first volume while maintaining the maximum number of existing elements. In addition, to achieve an improvement in its thermal performance, the façade is covered with a continuous 6cm SATE insulation reducing its transmittance and eliminating all thermal bridges.
The new building annexed to the existing one and which contains the rest of the classroom, has a concrete structure that is left visible to take advantage of its thermal inertia. The envelope is resolved with a ventilated façade system with a fully industrialized lightweight interior sheet with high thermal performance.
The flat roof has a ventilated chamber that improves its behavior against solar radiation, prevents overheating and isolates the classrooms on the lower floor from impact noise. On this roof is part of the existing photovoltaic field in the center.
Description of project by SUMO Arquitectes
The new Mar Bella School is the result of the reform and expansion of an existing school to go from one to two lines. The building is structured in three volumes that are interconnected to form a single complex. The first building is the original building built in the 50s and which is completely renovated.
The second volume is a new ground floor + 2 building connected at one end to the existing building. The third volume is a free-standing building that is joined to the other two by a bridge over the street. The first two volumes are organized in an L defining the school playground.
In them the most exclusive program of the school is developed: classrooms, administration, kitchen and dining room. The third volume, open to four winds, faces a square and three streets. It contains the gym / multipurpose room and the library. These spaces are used by the rest of the neighborhood and neighborhood associations outside of school hours.
Access to the school is through a large porch facing the courtyard. All classrooms have a lot of transparency both to the patio and to the corridors, allowing good lighting and natural ventilation. The spaces are versatile and flexible to favor new pedagogical projects.
The wide corridors are conceived as an extension of the classrooms where activities can be carried out in small groups. The roofs of the new buildings are used to expand the outdoor play areas, very precious and often scarce spaces in urban environments. The materials used throughout the work are self-explanatory. Simple, durable, resistant and low maintenance solutions. Concrete, wood and textile roller awnings are the dominant materials that give the whole a unified image.
The new La Mar Bella School has been conceived as a building with almost zero energy consumption (nZEB). It is an energy efficient school. With a low thermal transmittance envelope. Paying special attention to sun protection and promoting very good natural ventilation. Built with low carbon footprint materials. The complex has a 50kwpic photovoltaic installation that in turn generates shaded spaces in the play areas. The building has a class A energy certification.
REDUCE REUSE RECYCLE
The original building is reformed in depth while maintaining the maximum of existing elements. Its thermal performance is improved by insulating its entire envelope. The façade is covered with a continuous 6cm SATE insulation reducing its transmittance and eliminating all thermal bridges. On the roof, 8cm of rock wool is projected on the inside, giving continuity to the entire perimeter and taking advantage of the existing roof, which was renovated a few years ago.
The new building annexed to the existing one and which contains the rest of the classroom, has a structural bay of 7.40 x 7.85 m pillars and reinforced concrete slab slabs. The concrete structure is left exposed to take advantage of its thermal inertia.
The envelope is resolved with a ventilated façade system with a fully industrialized lightweight interior sheet with high thermal performance.
On the first floor and on both sides of the building there are terraces in flight and double height that with the help of mobile awnings in southwest orientation and vegetation in north orientation, act as a shade that generates an intermediate space between interior and exterior that is used as an area of games.
The deck is flat and is one more playground of the school. It has a ventilated chamber that improves its behavior against solar radiation, prevents overheating and isolates the classrooms on the lower floor from impact noise. On this roof is part of the existing photovoltaic field in the center.
Finally, the building that overlooks the square has a structure of beams and laminated wood slabs. Two large reinforced concrete walls support the entire structure and generate a large overhang over the square, a refuge and waiting area. Laminated pine wood beams with a 120 cm depth and a span of about 17m generating the different levels.
The floors are formed by tongue and groove pieces of laminated wood type HBS. A dry construction system that greatly reduces lead times and the material's carbon footprint. The solar protections are solved with fixed wooden brise-soleils and roll-up textile awnings. The mobile solar protection allows to control the solar radiation at the user's discretion, especially in the classroom areas, as appropriate in the different seasons of the year.
High performance installation systems and exposed layouts are used to allow easy maintenance and replacement. In many cases with decentralized systems that allow partial use of the building. The heating is solved with a high performance gas boiler and radiators with thermostatic valve with differentiated circuits according to orientation.
As it is a very large building, the DHW is generated with a double system that avoids long lines and associated pumping groups. An aerothermal heat pump is used in the kitchen and dining area, whose consumption is fully compensated with photovoltaic energy. Thermal plates are used in the gym changing rooms.
Ventilation is solved with different AHUs (11) with heat recovery units, distributed throughout the building, minimizing layouts and allowing great flexibility of use and hours. To involve and sensitize the educational community on energy saving and its influence on climate change, each classroom has a CO2 sensor formalized as a traffic light.
When the traffic light is green it indicates that the air quality is optimal, when it is amber it indicates that, if the activity and the weather allows it, it is a good time to ventilate the classroom naturally (taking advantage of the existing cross ventilation in all the spaces). In case of not being able to take advantage of natural ventilation, mechanical ventilation of the classrooms is carried out.
This system allows ventilation only when necessary, giving priority to natural ventilation. The building has two photovoltaic fields, one on the roof of the gym building and the other on the roof of the classroom. The combined power is 50.46kWpic.
The programmatic organization of the set allows great flexibility in its use. The patio can be completely opened to the square by means of 3 2m wide doors. The building facing the square can in turn open the entire façade by means of a large folding sliding window.
Parts of the school can be easily used by neighborhood entities and neighbors who so wish without having to open the school in the afternoons or on weekends when the teaching activity in the center ceases.
