The challenge

Lack of reliable cost data

When designing our earthquake-resistant schools in Nepal, we discovered a significant knowledge gap: local engineers and contractors had no experience or data for calculating costs for masonry buildings. Instead, they provided generic, one-page estimates meant for concrete frame buildings. We also found that these estimates were based on broad District Rates, which don't account for the dramatic price increases in remote, mountainous regions due to transportation costs.

Our extensive literature review confirmed this gap. We found very limited data on construction costs in seismically prone developing countries, and the majority of it focuses on reinforced concrete frames. There was no recent or reliable data available on the costs of earthquake-resistant measures, such as horizontal bands in masonry buildings.

What we needed to do

Because local estimates were not suitable, we decided to create our own detailed estimates based on localized costs in each village. We collected data through questionnaires, asking about local prices for both natural materials and manufactured materials, as well as labor costs for masons, carpenters, and other workers. This process has resulted in a unique database of localized costs and detailed cost analyses for our case study schools.

All of our initial findings and comparisons were published in 2019 (see link below), which was, to our knowledge, the very first paper of its kind. We are now expanding this research to include case study schools and houses in four different building typologies:

• Rubble stone masonry with a timber roof
  
  

• Concrete block masonry with a steel roof
  
  

• Confined masonry with a concrete slab
  
  

• Reinforced concrete frame with a concrete slab

Our research approach

For a fair comparison, we've developed case study buildings for schools and houses for all four typologies, ensuring they have similar heights and dimensions. The three-classroom schools are one story high, and the houses have two stories. The designs are common for the Himalayan region and include various earthquake-resistant features according to the current state-of-the-art, bearing in mind that some of these are still under research.

We have prepared detailed bills of quantities with the exact volumes, surfaces, and amounts of materials for each design. These estimates are divided into five main construction sequences: foundation, walls, roof, flooring, and finishing. For masonry walls, we have broken down the volumes of mortar and the number of masonry materials like blocks and bricks. Mortar and concrete mixtures are broken down into volumes of cement, sand, and aggregates, and so on.

Results

Schildkamp, M., and Araki, Y. (2019b). Cost Analysis of Mountain Schools in Nepal: Comparison of Earthquake Resistant Features in Rubble Stone Masonry vs. Concrete Block Masonry. Front. Built Environ. 5:55. doi: 10.3389/fbuil.2019.00055.

It can be downloaded free of cost from here.