Learning from best practices: the role of building technologies in the slum upgrading programme of Baan Mankong, Thailand

Abstract

Baan Mankong, Thailand’s national slum upgrading programme aims to improve the housing, living conditions and tenure security of the country’s urban poor. It gives its participating communities the flexibility to construct their houses with whichever building technology and materials they deem most appropriate. This is considered to be a key reason for the success of the programme, for which the Thai government has been praised by the United Nations Human Settlements Programme.

This research project investigated the various building technologies, materials and their corresponding supply chains utilised in the upgrading of one of Baan Mankong’s pilot projects, the Klong Toey Block 7-12 community in Bangkok, and assessed their environmental and economic impact. In particular, the research focused on the amount of CO2 emitted during the production process of the building materials and on the cost, time and sustainability of the various building technologies and materials employed. A simplified Life Cycle Assessment (LCA) was undertaken with the support of SimaPro (sustainability software) and a file containing LCA information for the construction sector utilising the KBOB database. Field work was carried out in Bangkok to gather necessary data since the quality of information obtained online or through other sources was deemed to be insufficient. In addition, the supply chains for the different building materials found in the community were traced using Google Maps.

The analyses showed that the cladding of the houses with fibre cement boards, masonry or hollow concrete blocks was the most important factor determining the carbon footprint of each household. To the extent that these materials could not be replaced by more environmentally friendly alternatives, minimising the cladding surface on the houses could also result in lower CO2 emissions. Even though timber is the least expensive and most ecological building material, the extensive presence of termites in Thailand’s tropical climatic conditions severely limits the longevity of wood. Using either concrete or steel avoids this issue but since the production of steel results in greater CO2 emissions, concrete is considered to be the preferred main structural building material. However, asbestos concrete columns should not be used due to the negative health effects associated with asbestos, making the use of in-situ cast concrete beams and columns the most desirable option. The project also established that although the provision of a general community contractor was generally well received by the community, the households who took up this alternative ended up paying a premium over and having to wait slightly longer than those who decided to erect their home themselves.