small , poor , densely populated and completely landlocked , burundi lies in east central africa bordering rwanda , tanzania and the democratic republic of the congo ( figure 1 ) . bujumbura , the capital city , lies at the north eastern end of lake tanganyika , the world 's longest freshwater lake which is surrounded by fertile highlands . the country is situated on a high plateau with the altitude ranging from 2,532  feet ( 772  meters ) at lake tanganyika to 8,760  feet ( 2,670  meters ) at the highest point , mount heha . this elevation greatly moderates the country 's tropical character and produces relatively cool temperatures , with an average of about 21c throughout the year in the central plateau and slightly higher temperatures in bujumbura ( 25c ) . there are four seasons ; the long dry season ( june - august ) ; the short wet season ( september - november ) , the short dry season ( december - january ) and the long wet season ( february - may ) . total mean annual rainfall is 33.3  inches ( 848  mm ) . 
  for centuries , the hutu , tutsis and twa people have coexisted in the area . historically , their differences were occupational in nature ; hutus were agricultural people while the pastoralist 's elite was identified as tutsis . the numerically and socially marginal group of pygmies was known as twa . at the start of the 20th century , belgium and germany occupied the area and rwanda and burundi were part of a european colony called ruanda  urundi . after world war ii , this mandate was superseded and both countries gained independence in 1962 - rwanda as a republic and burundi as a constitutional monarchy . since independence burundi has suffered from a long history of political unrest and armed ethnic conflict , marked by two major events : the brutal massacre of an estimated 150,000 hutus by the tutsi - dominated army in 1972 , and the 1993 mass killings of tutsis by hutu militia . an estimated 200,000 people from both groups died in the 12 years of low intensity warfare that followed the  burundi genocide of 1993 , before the signing of a peace agreement in 2005 . the peace accord was further legitimized through the voting of a new national constitution by the population , and the establishment of a mixed hutu / tutsi army , incorporating elements from the previously warring factions . presidential elections were also held at this time , issuing in an era of relative peace and stability . 
  with a total population of an estimated 10.6 million people , the country although recent political stability has proven beneficial , poverty remains extremely prominent the world health organisation ( who ) recognizes that there is a strong link between poverty and health , and that public health is critical for economic growth . in burundi , there are 0.03 physicians per 1,000 people . although free primary education has been introduced , according to the cia world fact book only one in two children go to school . less than 2% of the population has electricity in their homes and food and medicine are in short supply . the end of the civil war has improved aid flows and economic activity has increased , but underlying weaknesses  a high poverty rate , poor education rates , a weak transportation network , and overburdened utilities  handicap planned reforms . burundi remains heavily dependent on foreign aid , which currently represents 42 percent of its national income . according to who , life expectancy is 54 years compared to 78 in the uk . this is contributed to by a variety of causes , including non - communicable diseases , such as heart disease which , up until recently has been largely neglected . heart disease continues to be the leading cause of death and disability world wide , with 80 percent affecting low and middle - income countries . currently there are no dedicated facilities in burundi to deal with this problem , both in terms of prevention or care for the large number of affected individuals . this has led to the idea of establishing a state - of - the - art centre ( the burundi heart centre ) in an attempt to start dealing with this massive problem . strategies of how to address this global challenge and how to establish cardiac surgery programs in the developing world have previously been discussed . offer state of the art treatment to children and young adults with heart disease , free of charge at entry , in a purpose built heart unit . conduct research aimed at defining the size and type of heart disease in burundi to guide prevention programmes . the ambition for the pediatric heart centre is two - fold : firstly , it is to provide state of the art cardiac facilities to a country in high need for decent cardiac services . at the same time it is the intention to use inspirational architecture as a tool to improve lives , highlighting the fundamental values of healing and preserving the life of children and young adults in an environment that mitigates the sensation of stress and worry . engaging with africa comes with a potent cocktail of sentiments : sorrow , fascination , hope , and the nagging question whether outside help can avoid being patronising . from the early concept stages of the project it was therefore paramount to actively engage burundians in the project with the vision that they will become the future owner- operators of the center . following a bottom up design process , this not only applies to medical training but also to the construction process and maintenance of the building . in burundi , the palette of local materials is limited to compressed earth bricks , concrete , corrugated steel and natural stone- and these are typically associated with regress . therefore , the use of these materials in an innovative and contemporary way is a critical part of the design process , not least to provide some inspiration and living proof of their value to the local population ( figure 2 ) . another intention through the use of local materials was the strengthening of genius loci and cultural context : chinese building companies now dominate and propel the construction sector in africa and most materials in burundi are  if the budget allows chinese imports , mainly of low quality . this tends to not only weaken local building companies but also domestic expertise and skills . in designing the hospital it is the desire to find an architectural language that manifests the principles of care and healing and at the same time creates a contemporary vernacular architecture from local materials from burundi for burundians . the design follows three guiding principles:create a vibrant and inspiring building that is not only functional but harmonious in its design , structure , technique and use of materials.create a sustainable architecture that involves the local people and uses locally available materials in a contemporary and innovative way.use architecture to improve lives . create a vibrant and inspiring building that is not only functional but harmonious in its design , structure , technique and use of materials . create a sustainable architecture that involves the local people and uses locally available materials in a contemporary and innovative way . the cardiac facility will be situated on the grounds of the prince louis rwagasore hospital ( figure 3 ) . it is one of the oldest hospitals in burundi and was built in 1945 , its architecture revealing a strong european influence . the layout of the heart centre takes inspiration from an african village where the traditional hut , the  rugo ( meaning many huts ) is surrounded by a courtyard , and several houses are grouped together inside a wall ( figure 4 ) . whilst the surgery and icu block follow a rational layout , the wards and outpatient facilities are loosely arranged around two central spaces . the hospital buildings have been designed as single story structures to avoid being over- imposing and to provide a sense of intimacy , especially for young children ( figure 5 ) . the proposal works with a modular system that addresses budget constraints , allows for building techniques that can be more easily accomplished and at the same time provide for welcoming , social and enlivened spaces . the soul of the building is two inner sanctums ( green courtyards ) to which all public areas and surgery facilities have direct access , optimising the building 's microclimatic and healing properties . the roof of the surgery ward acts as the building 's battery , providing sufficient area for the installation of solar panels . the overhanging vaulted roofs of the smaller modules provide shade to waiting areas and protect the low - density brickwork during the rainy season . demarcation walls form a strong part of bujumbura 's cityscape , and a 2.5  m high brick wall secures the site for the heart centre . given that security of equipment and medication will be paramount , there is the desire to turn external facades and demarcation walls into social spaces , without losing their protective function . therefore external walls will incorporate shaded sitting facilities to connect the building with its immediate surroundings , creating public or semi - public space that can be shared by both hospitals on site . the use of contemporary cooling systems implies a large electrical or fossil fuel energy consumption . to mitigate co2 emissions there is a necessity to exploit renewable energy sources for cooling , heating , lighting and ventilating a building , creating a bioclimatic architecture . thick walls made of interlocking compressed clay brick will provide an appropriate thermal mass to cool the interior temperature during daytime . the roof structure of the outpatient and ward facilities consists of an outer vaulted skin that protects from rainfall and keeps the sun out . the inner roof structure is made of compressed clay bricks and forms a series of smaller perforated vaults to allow for warm air to enter a plenum that sits between these two roofs . in addition , plants in the courtyards will help cool the air and maximize comfort levels ( figure 6 ) . bujumbura 's excellent climatic condition means that the sun can be a potent and a clean energy source that allows for a fairly constant energy generation capacity throughout the year . in order to provide warm water and to cool down the areas that can not be subject to natural ventilation ( operating theatre , cath labs/ , icu ) pvc ( photo voltaic ) to empower local people and to make them part of a solution is paramount in finding a way to improve lives in an underdeveloped country . delivered by professionals but that the project involves a social commitment , where both medical training and the construction of the building reconnect locals with skills and knowledge to provide for a sustainable and possible future .
burundi is one of the world 's poorest nations , which is also reflected in its relative lack of cardiac facilities , particularly those catering to young children and adults . 
 the authors discuss current efforts to build  the burundi heart centre  to help address this challenge . 
 in particular , they highlight how the project can act as a case study for a sustainable architecture that involves local people and uses locally available materials in a contemporary and innovative way .