Building materials calculator

The Republic Government of Rwanda has adopted the National Housing Policy in 2015 (MININFRA 2015) with the overall vision of addressing the growing demand for housing in urban and rural areas and to encourage the use of local, green and affordable building materials. For future development, the use of mineral construction materials in Rwanda is expected to grow significantly. Materials for new dwellings represent almost 40% of the mass flow for solid matter in Kigali; the contribution to the energy flow is about 12% and to GHG emissions about 20%.

A comprehensive comparison of construction materials (e.g. traditional, compressed earth blocks, concrete, bricks, STRAWTEC panels, …) would be a highly valued contribution to support the National Housing Strategy.

Therefore, ifeu developed a building material calculator (BMC) as part of the Rapid Planning project that has been part of the Future Megacities Research Program of the German Federal Ministry for Education and Research (BMBF). The Microsoft Excel-based calculator is designed to analyse buildings by applying LCA results for the materials used in their construction. The LCA modelling covers extraction of resources, transport and pre-construction of the building materials.

The BMC covers a selected range of material types and construction methods applicable to Rwanda. The user interface shows the house structure elements from foundation design, shell, ground floor, structural frame to the roof elements. For each element, users may choose the desired material and specify the related quantity. Based on the chosen values, the calculator provides results for the categories Climate Change, Energy Demand, Fresh Water Use and Land Use.