Bridging the Knowledge Gap: the key to cost effective and structurally sound construction in remote regions
I have been working in the field of architecture and construction for over 5 years in remote parts of Central Africa, specifically the Great Lakes Region. Repeatedly, I’ve observed that the greatest barrier to building a safe structure is not always a lack of material resources, but rather a lack of expertise and access to information. The built environment experts who do work in these countries are often focused on infrastructure projects in major cities. The lack of training and regulations to guide the local designers and builders who are responsible for the vast majority of houses, churches, schools or other community projects – which are often adequately funded – results in very costly mistakes. Bridging this knowledge gap is critical to ensuring that the investments these communities make in the built environment are structurally sound, cost effective and durable.
Practically speaking, the lack of expertise and access to information in remote areas results in both poor construction techniques and bad planning. In the case of reinforced concrete technology, which is the main structural material used in this region, poor mixes, wrong sizing of columns, beams and reinforcements often lead to structural failures, which can be fatal.
Local foremen often believe, for example, that adding a lot of water to concrete mixes produces the best concrete. Workability can be improved with plenty of water, especially when the concrete is mixed by hand, but the compressive strength of concrete is reduced significantly. In two cases, I had to demolish concrete structures because of bad compressive strength results for concrete that was poorly mixed. In Beni in the Democratic Republic of Congo, it was almost impossible to achieve 15MPA for a structure designed for 20 MPA. The solution? We had to hand-wash the sand and drastically reduce the amount of water in the concrete in order to reach a safe standard.
Case Study in Burundi
Another problem I often see is incorrect phasing of a construction project. During my time as construction manager at a hospital in rural Burundi, I led a team of nearly 110 masons, carpenters, steel workers, welders and plumbers. I learned that Burundian men are expected to build a house before they can be married, because this achievement is a sign of manhood and responsibility. So, many of my team members were engaged in their own personal construction projects, and I was invited several times to give technical advice.
These small houses are generally built with a stone foundation with cement or mud mortar, burnt brick elevation walls made with mud mortar, reinforced concrete columns and beams, and corrugated iron roofing sheets on wooden trusses. Due to their limited income and lack of access to credit, Burundians often build in phases starting with the foundation work. Then comes the brickwork, which is left exposed to rains, and deteriorates over time. Beams and columns are added later, when more funds are gathered, then comes the roof, the concrete floor and finally interior and exterior finishing works. Before the building is completed, structural defects, cracks and sagging are observed.
During the construction of a multi-unit residence for the hospital, I modelled a different approach to phasing that would protect the structural integrity of the building. Together with the construction crew, we started with the foundation work and the ground floor slab as the first phase to allow us to protect the foundation and substructure against rainwater damage. The columns, beams and slab of the first floor came in second place. This allowed us to advance more quickly in height. The third phase was the roof to allow us to cover the building and work inside the building as the rainy season approached. The fourth phase consisted of raising interior and exterior walls without fear that they would be affected by inclement weather. The fifth phase included interior and exterior finishing, placement of doors and windows, ceilings, tiles, and installation of plumbing and electricity. The last phase dealt with erosion control. We created terraces on steep parts of the site and planted grass to stop soil erosion and to reduce the velocity of surface runoff. Finally we built a drainage system to collect rainwater and divert it away from the building to prevent it from collapsing in the long term.
So how can we bridge the knowledge gap for builders in remote regions and prevent wasted resources and unsafe buildings that endanger lives? One answer is to better equip small-scale built environment professionals who have basic design training and certify them for projects of limited scope. In general, there are very few licensed built environment professionals in Central and East Africa because architecture and engineering degrees are challenging and costly, and licensure is restricted to those with the most advanced degrees. These degrees are not accessible to the vast majority of people, including local builders who are generally responsible for most construction projects across the country. This level of response requires the initiative of national governments, universities and licensing boards to re-examine curricular content and outcomes for all certificate and degree programs in this field. (The Commonwealth Association of Architects has argued for these reforms based on a 2020 study of design professionals’ capacity to respond to global challenges.) Such a collaborative approach in Central Africa could increase significantly the number of built environment professionals per capita. It also has the potential of making these services more affordable and accessible to remote communities in the region.
Even in the absence of national scale reform, existing built environment professionals and firms have an opportunity to creatively disseminate technical knowledge to builders at the grassroots level. This sort of intervention can take several forms. Professionals could develop and publish basic construction guides, which take into account the technological and socio-economic realities of these remote regions. Firms could offer workshops and short courses that are accessible to remote builders in terms of price, location and language as a corporate social responsibility project that leads to meaningful change in society. Finally, built environment professionals with advanced degrees can be more willing to share information and knowledge with local foremen and construction crews they encounter on various sites. Problem solving together will lead to innovative solutions.
From my perspective, valuing and equipping local builders is worth the effort because it results in better construction practice, efficient use of resources and knowledge exchange with long lasting benefits for everyone.