Carbon offsetting with bamboo-based social housing: A case study in the Philippines
Abstract
Due to the significant shortage of affordable housing in the Philippines and the pressing issue of climate change, there is an urgent need for greener and cheaper buildings.
A possible solution are cement bamboo frame buildings, a combination of traditional bamboo building methods and modern industrialized materials which is currently being employed in social housing projects in the Philippines.
To determine the environmental impact of such buildings, a dynamic lifecycle assessment (DLCA) calculation is applied. With DLCA, the environmental benefits of temporary carbon storage in biogenic materials can be explored, which proved to significantly reduce the overall CO2 balance of the building. For the time span before the end of the building’s life, biogenic effects compensate about 43 % of the total emissions from production. For a longer time period of 100 years, temporary storage is still responsible for a reduction of total emissions of 14 %. The simplified semi-static DLCA approach “GWPbio” produced accurate results for an incineration scenario at the end-of-life of the buildings, when compared to the results computed using the standard DLCA methodology. For a landfilling scenario, GWPbio significantly overestimated the impacts of methane emitted during the landfilling process, meaning that a full DLCA model is recommended in such scenarios to accurately estimate the environmental impact. In a comparison with concrete brick buildings, using bamboo instead meant an overall reduction of emissions of 69%.In addition, the investments necessary for a cement factory were determined to be much higher than the investments for the facilities required to cover the same housing demand using bamboo materials instead.
Finally, the construction of bamboo buildings was examined in terms of its potential as a carbon offsetting strategy. Turning an unmanaged into a managed plantation triples the amount of CO2 stored in biogenic materials in the long-term with additional positive impacts from replacing concrete brick buildings, since the avoided emissions from switching the building material outweighs the net-emissions of the bamboo buildings. Construction with bamboo was therefore determined to be a viable strategy for carbon offsetting both in terms of emissions reduction potential and economic viability.