# Community centre of El Rodeo de Mora

- El Rodeo de Mora - Costa RicaCommunity centre of El Rodeo de Mora

###### Photography: Fernando Alda

El Rodeo de Mora is a rural and economically disadvantaged community in the Central Valley of Costa Rica.

We detected a great opportunity to offer architecture that celebrates and dignifies community, something considerably rare in Costa Rica. The small building complex consists of a new “community room”, a kitchen, toilet rooms, storage plus a new facility for the soccer teams (dressing rooms, etc.) and bleachers.

The project budget was extremely low: +/-US$180,000 to build +/- 750 m2. Normally, at current construction costs, a building of this type costs between +/- US$800 and $1,000/m2. We managed to build it for less than US$250/m2 due to its essential design and to donations of some materials, including broken ceramic tile that was used to finish as many surfaces as possible (walls, floors). Our studio also donated certain items (e.g. toilet accessories, fire extinguisher, some material for main hall doors, etc.).

The thinking behind the concept is quite essential: tropical and bioclimatic site-specific design with local materials that would express sense of community, sense of place and sensorial innovation (visually, spatially, materially) in a community accustomed to uncultured design, and a formal expression that emerges from its place.

Thus, the plan shape of the “community room”, symbolizing “reunion”, is a circle that three-dimensionally becomes a cylinder made of clay “ventilation” brick that generates a confortable interior environment in a location with high temperatures (+30°) and high humidity (up to 90 % R.H.).

The circle has many meanings or symbolisms. Among them, totality, wholeness, original perfection, boundary and enclosure, completion, etc. We derive that it symbolizes community and gathering, union and re_Union. It is a stable form that we relate to Democracy and, again, community. We wanted a community room that “embraces” the community, that makes it whole, that protects it, that celebrates re_Union and togetherness.

On another plane, a more pragmatic and mathematical one (even economic), the circle is the most efficient form. If you compare, for example, a square that measures 10 x 10, the area is 100 but the perimeter is 4 times 10, 40. A rectangle in order to reach 100 square meters, for example, could be 5 x 20 (two sides of 5 and two sides of 20) adding to a perimeter of 50. The more elongated the rectangle, the less efficient because two of the sides get to be longer in order to reach the same area. A circle of 100 square in area is A=πr2 or r=5.64. The circumference is 2πr = 35.45. So, for the same area, the perimeter of the rectangle is 50, the perimeter for the square is 40 and the perimeter (circumference) of the circle is 35.45. You can see that the circle requires less perimeter than a square or a rectangle. Thus, a circular building requires, among other things, less materials for the foundations and less materials for the walls and so on and so forth.

Its design is earthquake resistant due to its shape, materials and architectural and structural solution and, furthermore, due to the strict seismic code we have in Costa Rica (one of the strictest in the world).

There was a programmatic requirement that it serve as an emergency shelter in case of a disaster or a catastrophe such as earthquakes, fires or floods. The building is the largest building in the community. It can certainly hold at least 200 sleeping places in case of an emergency. It happens to be on pretty high ground especially with respect to nearby rivers. On the other hand, it is located in a rural area surrounded by an enormous natural reserve called El Rodeo Protected Zone with 1,875 hectares.

Roofs are revolving and pitched with long overhangs to respond to the local climate, made of corrugated lightweight fiber-cement roofing sheets 1 meter wide by 2 meters long and 7 mm thick. Its shape is generated by two parts:

- A series of eight independent segments of pitched roofs, four at a lower elevation than the other four. The higher four gyrating on top of the lower four thus enabling to cover the full area of the building and spaces under the overhangs or eaves with simple rectangular geometries, as the generation of a circular roof would have been much more expensive with lots of waste from cutting the rectangular sheets of fiber-cement roofing. At the same time, generating a roof with much movement and interest, and lots of space for cross ventilation.
- A sort of “cupola”, at yet a higher elevation, formed by segments of pitched roofs at higher inclinations than the lower eight, and vertical gabled walls formed by metal slats that allow for additional ventilation.

Thus, the entire building is a system for natural air movement. As hot air rises, cooler air is sucked into the interior space (this is simple Boyle’s Law) and the higher hot air is pushed out by outside air crossing thru the spaces between the various segments of the roof as well as the ventilation slats.

The roof structure is a system formed by three layers of interconnecting simple lightweight square section steel tube trusses. The bottom layer revolves around a large square. The second layer revolves around an octagon. The upper second layer has structural steel cables as bottom chords (the lower part of a truss) to reduce weight and cost of the structure. The third layer is a simple flat diaphragm but sloped at a higher pitch than the two lower layers, creating a “cupola.” The end result is a three-dimensional roof system. The fiber-cement panels are then supported by the steel structure. The entire steel truss system sits on exterior perimeter cylindrical reinforced concrete columns tied together with perimeter rectangular steel tube beams. The steel truss system was assembled in sections on site then lifted by workers using temporary pilotis and ropes. Then the sections were welded together and placed on steel seats held by steel rings located at the top and sides of the concrete columns. Thus, the trusses allow for a nice free span of 22 meters. The interior circle is 16 meters in diameter (201 square meters). Then outside of the circle we have 2 meter wide walkways covered by the roof overhangs (needed to protect from sun and rain as well as to respond to local tropical architectural traditions.

Project: Community centre of El Rodeo de Mora

Architects: Foroarquitectos

Photography: Fernando Alda