Locally-manufactured cob and bamboo school building

Construction

In order to execute the two-level building complex in a manner able to withstand earthquakes, separate axis-symmetrical structures were produced in two building phases. The ground floor has a heavy earthen body and the upper floor is a light bamboo structure. The baked brick foundation projecting 600mm from the ground forms the base of the structure and protects from water degradation or water ingress.

Classrooms on the first floor were built using the half-timber technique; the light bamboo structure is filled with brick earth and covered with bamboo weave, providing protection from sun and rain. The classrooms are connected via a two-level bamboo veranda, which also serves as an extended classroom. This also provides protection from monsoon rains. The ceiling and classic flat-roof structure consists of a triple-layer bamboo structure that is covered with a layer of earth.

Design concept

The new school building consists of the required eight classrooms and service areas, located in two earthen structures. A bamboo load-bearing structure which supports the staircase, service areas, and a free-study room is located between the earthen structures. The classrooms in the ground floor feature large window niches directed towards the south. The balcony on the first floor features benches made of mambo and earth to provide additional seating.

Traditional building technology is upgraded through clever application of technology

The school – currently being constructed – is erected by Ziegert | Roswag | Seiler Architekten Ingenieure with local craftsmen using earth and bamboo. The design continues local building traditions, and it is intended to act as an example of modern earthen architecture in Pakistan. In addition to ecological and economic criteria, social aspects such as the creation of a local identity also played an important role in the design process.

The construction of the school’s extension has been coordinated to match the capabilities of local craftsmen so that they are able to build within the local context. During implementation, the participating craftsmen are trained as specialists in the improved building system. In the long-term, Tipu Sultan Merkez (TSM) plans to expand its vocational training activities and become a contact partner in the region for construction projects using these techniques.

Building shell completed

Construction commenced in February 2011, and the first building phase of the school has already completed the building shell, and craftsmen are currently beginning the interior. The architects consider the structural extension of the school to be a further example of the current approach by sustainable architects to use a greater proportion of local and natural materials. Ziegert | Roswag | Seiler Architekten Ingenieure has already received the Aga Khan Award for Architecture for a school project in Bangladesh. In Mozambique they were able to implement eleven schools in a village setting together with the Aga Khan Foundation. They are currently planning a cultural center in Ghana, and they are also planning and implementing a health center in Ethiopia.

Continued progress

In June 2012 (after a couple of difficulties to get lime for the roof sealing and the parts for the drainage) the roof moved towards finalization and sealing in good time prior to the rainy period. The wooden windows, manufactured in Lahore, have been installed and bamboo works on the façade performed by the Pakistani team are in progress. The building is almost finished before the summer break, during the rainy period. Residual work can be implemented in autumn before the new school year begins. From then on, lessons can take place in four additional classrooms.

Symposium in Pakistan, exhibition in Germany

On November 30, 2011 the project participants discussed the applied strategy together with those involved at a symposium in Lahore, Pakistan and installed a local network for fostering natural building systems in Pakistan. The symposium was co-organized by the Institute of Architects in Pakistan (IAP), the architects and TSM with the support of the German Society for International Cooperation (GIZ), Aga Khan Cultural Service Pakistan, Verein für Entwicklung, Bildung und Selbsthilfe e.V. (vebs), and the Habitat Unit of the Technical University of Berlin.

The project also features in an exhibition at the Aedes Forum in Berlin. MACHEN! the German winners of the Holcim Awards 2011/12 features all six Holcim Awards prize-winning projects connected to German architects. Three discussions are held at the ANCB Metropolitan Laboratory to provide an overview of each project and report on progress since the initial submission in the Holcim Awards competition was prepared. The exhibition runs July 13 to August 30, 2012.

Project background 

This school project in the small village of Jar Maulwi, 35km northwest of Lahore, is an extension of the existing Tipu Sultan Merkez School, which has provided education for underprivileged rural girls for more than ten years. The new two-story building, Earthen School Tipu Sultan Merkez, constructed from locally-sourced cob and bamboo will provide seven new classrooms. Mitigating earthquake risks, the structure is divided into two compact parts connected by a light gallery. The 60 cm thick ground floor walls are made of cob, a mixture of clay, sand, straw, water and earth and supported by brickwork foundations which protect against moisture ingress from the soil or rainwater. 

The upper floor is a bamboo construction with an earthen filling. Intense research on cob construction resulted in a useful increase in strength and durability, and extended maintenance intervals compared to former methodologies. The high humidity absorption capacity and significant mass of the earth walls reduce interior temperatures by up to 8 °C during summer where temperatures exceed 40 °C. South-oriented glazing produces solar gain during winter. The local residents build the school and are thereby educated in this improved approach which creates an opportunity to establish their own local enterprise and transfer this highly appropriate construction technology to other building projects.

The new construction approach shows the rural population an affordable, high quality and durable alternative compared to widely-used, but higher-cost and less environmentally-compatible construction materials. The combined earth/bamboo structure allows two-level buildings which reduces land use. The low-tech but sophisticated approach creates the potential to develop a unique local architecture, and transfer the approach to many other regions, particularly in less-developed countries.

The 60cm thick ground floor walls are made of cob, a mixture of clay, sand, straw, water and earth and supported by brickwork foundations which protect against moisture ingress from the soil or rainwater. The upper floor is a bamboo construction with an earthen filling. Intense research on cob construction resulted in a useful increase in strength and durability, and extended maintenance intervals compared to former methodologies.

The high humidity absorption capacity and significant mass of the earth walls reduce interior temperatures by up to 8°C during summer where temperatures exceed 40°C. South-oriented glazing produces solar gain during winter. The local residents build the school and are thereby educated in this improved approach which creates an opportunity to establish their own local enterprise and transfer this highly appropriate construction technology to other building projects.