Malaria, diarrhoea and pneumonia are preventable childhood diseases that are major causes of death in young children. They’re transmitted largely in and around the home, where children spend most of their time.
For example, around 80% of malaria transmission in Africa occurs when people are bitten by malarial mosquitoes indoors at night. Diarrhoea results usually from food and water that’s been contaminated by faeces. It can also be spread through poor hygiene. Pneumonia is spread through overcrowding and poor ventilation, and is exacerbated by indoor air pollution.
We are an international group of specialists from different fields including architecture, communications, global health, medical anthropology, public health entomology, engineering and statistics.
To see if it might be possible for a newly designed house to help prevent malaria, pneumonia and diarrhoea in children, one of us (Danish architect Jakob Knudsen) came up with a new design. We called it the Star home.
This house costs 24% less in materials than a conventional single-storey cement-block house. It also uses 73% less concrete, and generates 57% less embodied carbon (the amount of carbon emissions released from the time raw materials are turned into building materials for the house to the end of the home’s life). Our analysis revealed a fourfold return on investment over 50 years once health, water, cooling and energy savings are accounted for.
The features of the Star home are:
- Double-storey buildings. Bedrooms are positioned on the upper floor, away from mosquitoes, which are most abundant at ground level.
The Star home in the background.
Courtesy Julien Lanoo
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Cross-ventilation, where air passes across the room. We increased ventilation inside the home by using walls made of shade net, instead of solid walls. These also cooled sleeping areas and deterred mosquitoes from entering the room.
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Mosquito screens on doors and windows. These screens keep malaria mosquitoes and flies out.
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Self-closing doors. These minimise the entry of mosquitoes and flies.
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Clean water harvesting, improved pit latrines and improved cooking stoves.
We put the Star home through a three year, peer-reviewed trial to see if it could reduce malaria, diarrhoea and pneumonia among children.
Our findings were startling: After three years, children living in the Star homes had 44% less clinical malaria, 30% less diarrhoea and 18% less pneumonia than those living in traditional houses.
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Nigeria has Africa’s highest malaria death rate – progress is being made, but it’s not enough
Because they were protected from three serious illnesses, their overall health improved and the children grew taller than children living in traditional houses.
Our study also demonstrated that the new, comfortable Star house has a lower carbon footprint than the cement-block houses that are currently built in sub-Saharan Africa. Put simply, we used less energy to build a Star home than is used in building a typical cement house constructed in a village.
We also found that passive cooling in the Star home made the home more comfortable in hot weather even though it did not have air conditioning, which consumes energy.
Our study demonstrates that small improvements in design are likely to make a major health impact on the lives of children in Africa.
The ground work
We first set about understanding how the pathogens causing the three diseases spread in and around the home.
Malaria: How mosquitoes enter houses has been the subject of research for decades.
Research shows that they find people mainly by smell. From far away, they follow the carbon dioxide humans breathe out, and when they get closer, they are guided by smells produced by bacteria on human skin.
Diarrhoea: Houses with a regular supply of clean water, clean food preparation areas, fly-proof latrines and kitchens can help reduce the spread of this disease.
Pneumonia: This is spread through air-borne pathogens and is made worse by smoke-filled kitchens which damage the lungs.
The Star home.
Courtesy Julien Lanoo
We then developed the Star homes and tested whether they were healthier by carrying out a randomised controlled trial in southern Tanzania, an area with high levels of malaria.
In the trials, we recruited children under 13 years of age and randomly allocated them to 110 Star homes and 513 traditional mud and thatched-roof houses.
These children were followed weekly for signs of illness for three years and the data from the clinical trial were analysed.
Africa’s housing boom: a chance to build healthier homes
Africa’s population is the most rapidly expanding in the world, with the current population of 1.5 billion people expected to increase to 2.7-3.7 billion by 2070.
Hundreds of millions of new homes will need to be constructed soon.
There has never been a better time to build healthier homes on the continent. Improvements in rural housing are increasing at a fast pace.
Read more:
Building Zambian homes with local materials delivers benefits that imports don’t: study
Governments can take a number of steps to help. For example, they can facilitate the construction of better rural homes by assuring ownership rights (titles). These are essential for homeowners who want to apply for loans to carry out healthy home improvements. Governments could also reduce import taxes on fly screening, and provide advice and support for the construction of healthy homes.
We hope that this study will stimulate further innovation by people working in the built environment who could collaborate with local communities to construct healthier homes for rural people in low- and middle-income countries. Simple improvements in housing can have profound impacts on improving public health.
(About our team: Salum Mshamu, a Tanzanian scientist, carried out trials on the Star home as part of his PhD studies at Oxford University. Jakob Knudsen has been designing healthy and cooler homes in the tropics, particularly in Tanzania, for over 30 years. Lorenz von Seidlein is a paediatric clinician who has studied the epidemiology and control of childhood infections, principally malaria, in different parts of the tropics. Steve Lindsay has over 40 years of experience working on the control of mosquitoes and flies, including running clinical trials of housing interventions.)