By Olivia Nielsen and Sabine Kast
Most of the building stock that will be needed over the next century in Africa is yet to be built. As the last continent to urbanize, Sub-Saharan Africa has a unique opportunity to learn from others and adopt resilient and sustainable practices from the onset.
Africa’s cities are already booming as thousands of rural households move to find better opportunities in the cities. Though the COVID-19 pandemic may have temporarily slowed this rural-to-urban migration, the trend appears to be inevitable.
The continent is not immune to natural hazards as the South gets hit by stronger and stronger cyclones, causing devastation and loss of life, homes and livelihoods. An estimated 240,000 houses were destroyed or damaged last year alone in Mozambique. North, South and east Africa also experience regular earthquakes.
A new motto has emerged claiming that there are no natural disasters, shifting the blame to poorly designed built environment and inadequate prevention systems which contribute death, destruction and economic losses.
Yet, Africa’s building sector seems to be repeating some of the mistakes of the past. Quality control remains a major issue across the continent where buildings are known to collapse even in the absence of natural hazards.
The COVID-19 pandemic has highlighted the need to urgently invest in disaster preparedness and mitigation. A disaster can quickly destroy decades of economic progress. While earthquakes are a quick disaster, a pandemic is a slow moving one. Our built environment must be designed to withstand these disasters and protect us.
Fortunately, resilience doesn’t need to be expensive and new technologies and innovations are constantly bringing down costs. As we are required to work remotely, we are developing new technologies to improve risk reduction during the pandemic and beyond. A few examples:
- Machine learning to develop risk maps. Formal maps are rarely updated in Africa and often only cover major urban areas. Yet, local risk maps are fundamental to supporting proper urban development and reducing risks in the long term. Without risk maps, it is difficult to anticipate which properties may be vulnerable to flooding, landslides or even earthquakes and typhoons. Developing these maps should be a major priority to support planned urban development and make investments that will last. When on-the-ground data collection is time-consuming or made difficult with social distancing requirements, machine learning algorithms can be used to process satellite data and build local risk maps. This technology can help Africa overcome its major map gap and support municipalities across the continent develop urban plans that mitigate the risks of flooding, landslides and sea rise. Without access to detailed risk maps, buildings may be built in precarious ways which may lead to devastating life and property losses. Fortunately, machine learning is making this mapping process cheaper and faster.
- Artificial Intelligence to assess the built environment. The World Bank’s Global Resilient Housing Group has developed technology to capture images from satellites and drones, which are processed through an algorithm to assess structural deficiencies. Without even setting foot on the ground, thousands of buildings can be assessed in a matter of minutes and enable policymakers to prioritize interventions. For example, buildings that present a high risk of collapsing during an earthquake or typhoon can be efficiently identified and thus retrofitted before the next disaster strikes.
- Apps to undertake remote quality control. New apps, such as iBuild+ Miyamoto, have been developed to enable homeowners to quickly undertake a damage assessment of their home. Just like telehealth, they now have expert engineers at the tip of their fingertips- for a fraction of the cost! By uploading geotagged photos of their homes, households can access expert advice at a fraction of the costs. This app can also be used to monitor the quality of construction works and identify issues in real time before it is too late.
- Programs to address and rate the resilience of new buildings: IFC, the private sector arm of the World Bank Group, is piloting a new program, the Building Resilience Index. The Index standardizes and quantifies disaster risk, gives guidance on risk management, and creates a reporting system on adaptation and resilience for the construction sector. The new tool will enable construction developers to identify ways of improving building resilience while minimizing costs. For investors and households, the Index will provide reassurance that the building can withstand significant hazards and protect both lives and properties.
- Low-cost retrofit solutions. Retrofits are so rarely undertaken because they are deemed too expensive by both households and policymakers. Building new homes is easier to implement instead. But now, new construction technologies, such as Polypropylene (PP) bands or fiber-reinforced paint, are emerging that will not only make these retrofits cheaper but also much easier to implement. With little training, households can easily apply these retrofits themselves and bypass engineering and labor costs- which can often be crippling. Though easy to apply, these technologies are effective and enable households to greatly reduce the likelihood of structural collapse.
Construction will be a major driver of economic recovery worldwide, accounting for around 13% of the global GDP. These innovations can be part of a global effort to build (back) better. As cities in Africa continue to grow, climate change continues to accelerate and jobs are desperately needed, there has never been a better time to invest in resilience!