The proposal for the international competition for a cyclone shelter in Bangladesh by Lindsay Bremner and Jeremy Voorhees is conceptualized as a boat-building, referencing two local typologies – the boat and the landing ghat. Located in Ranggabali, a small village in the Patuakhali Province, the building is half submerged in water in times of cyclone flooding while beached against a concrete ghat in dry seasons. Sheltering its occupants in the liminal zone between land and water, it makes place by transitioning from depth and section to surface and plan. More images and architects’ descriptions after the break.
The shelter is entered up two flights of stairs, flanking a large stepped plinth which functions as site of social interaction and exchange during dry seasons, and for boat mooring and animal tethering during cyclones. People congregate in its hull, a woven interior space lined with layers of bunk beds and bamboo culm screens. Circumambulating this interior space at first floor level is a walkway behind a perforated concrete screen that registers the movement of the wind. Here, and in the entrance portico, small livestock and poultry are temporarily sheltered out of the wind during cyclone season. The rest of the year, these serve as extensions to interior space and vantage points from which to view the road.
The concrete screen wall is cast in panels on site using bamboo as formwork for its perforations. It disrupts air movement and abates the build-up of internal air pressure inside the shelter, one of the chief causes of building failure under cyclone conditions. Behind this screen a second layer of solid bamboo opening sections locks down during cyclones, but opens the entire length of the building at other times, providing cross ventilation and filtered light to the interior space. A suspended bamboo deck provides more sleeping space during cyclone season, serving as meeting space or school room at other times.
Underneath the entrance stairs, an enclosed water cistern contains water harvested from the roof, accessed via hand pumps at the building’s entrance. The rate and drop of monsoon rains falling on the roof and channelled into this cistern drive a turbine to generate power, stored for use on site. Bathrooms and kitchen are stacked at the rear of the building, ventilated through ducts to the roof. They are serviced by an additional cistern containing water harvested from the roof, filtered through sand and gravity fed to sinks and toilets. Waste water is fed to a three compartment septic tank and sand filter, from which it can be hand pumped for irrigation.
The shelter’s hull, first floor slabs, column structure and roof are made of bamboo reinforced concrete, while other elements – interior deck, screen walls and opening sections are made of bamboo lattice, of different densities and configurations. The hull walls, containing the primary habitable space of the shelter, resist flood waters. Torque is resisted by this mass of water and the concrete water cisterns at both ends of the building. The roof is shaped to provide least resistance to the wind from the south west, the cyclone bearing winds.
Architects: Lindsay Bremner and Jeremy Voorhees Location: Ranggabali, Patuakhali, Bangladesh Assistant: Robert Merow Project: International Competition for a Cyclone Shelter in Bangladesh Design Date: January 2010