1. Climate Change
The world is facing twin unprecedented challenges of global warming and biodiversity loss. According to the recent report by the UN Intergovernmental Panel on Climate Change (IPCC) we have only 12 years to change direction on greenhouse gas emissions before we reach a situation where global warming becomes irreversible. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) has stated that we are currently in the midst of the sixth mass extinction on planet earth. The need to face up to these crises lies primarily with the industrialised countries of the world, but most of Africa will have to adopt policies of both adaptation and mitigation as they undergo a process of rapid urbanisation and economic growth. An holistic approach to sustainable building design is one way in which the worst consequences of these crises can be avoided.
According to the IPCC, East Africa is among the world’s most vulnerable regions to the impacts of climate change.
The climate in most of East Africa is relatively benign i.e. temperature and humidity levels are comfortable for much of the year compared to areas with much more extreme conditions. However, with the rapidity of global warming, weather conditions are likely to become far more extreme. The report ‘Impacts, Adaptation, and Vulnerability’ by the IPCC, outlined significant risk to the region from a projected increase in hot days and heavy precipitation. Buildings must therefore be designed to mitigate the effects of extreme weather conditions, taking into account regional variations. Online resources can provide easy to understand data on temperature, humidity, rainfall and ventilation throughout the year, which can be used to influence building design and ensure ongoing comfort conditions.
East Africa faces unique infrastructural challenges as a result of high rates of urbanisation and some of the highest levels of population growth in the world.
With an average population growth rate of 6.7% between 2013 and 2017 – double the African average – East Africa is one of the fastest growing regions in the world. This increase in population will put huge pressure on the region’s cities and overburdened infrastructure, and will undoubtedly lead to urban expansion and an increase in demand for new housing and school communities.
This guide focusses on single-storey structures in peri-urban or rural areas, though with the intensification of urbanism it is anticipated that 2-3 storey buildings will become much more common. This will introduce a new range of concerns such as the structural stability of multi-storey structures and the additional cost of stairs and lifts.
Percentage population growth by 2080 over climate change vulnerability. Circle size represents current population size. Data Source: UN Department of Economic and Social Affairs 2019
Most East African schools are thermal uncomfortable to the extent that they create adverse internal conditions that are not conducive to inspired learning.
Typical school buildings are single storey structures with pitched roofs and simple window openings. Unfortunately, they are often thermally uncomfortable, to the extent that classrooms do not function as spaces offering shelter, but create adverse internal conditions. For example, darkly painted or corroded single sheet metal roofs may heat up to 60°C during the day - even in well ventilated spaces. This has negative consequences for a rising new generation requiring good and efficient education. Even more concerning is that as equatorial East Africa will be severely affected by global climate change, the need to design resilient buildings that do not rely on artificial space conditioning will become more and more critical for comfort and inspired learning.
NTC Kaliro Before being renovated and expanded the NTC Kaliro had metal sheet roofing that regularly heated to over 50 degrees C.
As schools are typically remote, electricity is not always available, and accessibility is limited. Solar PV provides a sustainable and reliable solution.
Energy use in schools is likely to increase as computers and other electrical equipment become more intensively used and demand grows for the use of buildings outside daylight hours. However, connection to a municipal grid is not always available in rural locations and electrical supply is anything but reliable. Locally integrated solar photovoltaic systems address a certain degree of grid-independence, while being far more sustainable than centralised energy generated through the burning of fossil fuels, or polluting diesel generators that can be damaging to health. Solar PV systems are reducing in costs year on year though they are still relatively expensive. Their advantage is that they run simply on the free and abundant solar energy available in the equatorial climate and produce zero CO2.
Standard solar photovoltaic cells mounted on a 15 degree pitched roof; an affordable, accessible and sustainable energy source.
Imported materials have high embodied energy from transportation and fail to add the same benefit to the local economy as the use of local resources.
East Africa has an overreliance on imported construction materials such as cement and metal sheet roofing. The problem with imported materials is that the added CO2 from transportation contributes towards creating high embodied energy buildings. Comparatively, locally sourced materials have low embodied energy and help to build local economies through job creation, although local materials can become scarce if not managed responsibly. Compressed earth for instance is readily available on most sites, and can provide a low-carbon alternative to fired clay bricks. Timber is a low-to-negative carbon material providing it is part of a sustainably managed plantation where new trees are planted to replace the ones which are cut down for construction.
Ilima Primary Cement-free mud bricks were made with earth from the nearby termite mounds to create a stronger cohesion.