Using Indigenous Earthen Architectural Knowledge

By Lesley Freedman

In South Africa’s rural areas, indigenous earthen architecture can be seen everywhere. Indigenous Building Systems form the core of most of South Africans’ architectural knowledge, passed down through generations, solving the challenges of waterproofing in the most inspired, resourceful ways.

Pondoland, Eastern Cape

Pondoland, Eastern Cape

Some of this knowledge continues to be used, but increasing homogenisation, control and authority threaten these expressions of our cultural identities. Knowing and valuing and defining our cultural identity contribute to our overall wellbeing.

“Earth has been one of the most widely used building materials ever since people began to build homes and cities 11 000 years ago. Earthen architecture is the world’s most ancient and most prevalent existing architectural expression. In most places in the world, earth is the conventional building material” (Houben & Guillard: 1994). For example, in Peru, 60% of the dwellings are built in adobe or rammed earth and in Mendoza, Argentina, more than 80% of the rural population has built their dwellings in adobe. In Uganda, 90% of people live rurally, in earth structures.

Earthen building in rural South Africa

Earthen building in rural South Africa

Today millions of us continue to house ourselves using these building methods, but not in urban areas where they are most needed.  Urban human settlements are being built with materials that contribute little to the comfort of the inhabitants in terms of thermal content, safety or fire resistance. Earth has good insulation properties. It does not consume much non-renewable energy, uses very little water and is recyclable. Earth is a porous, breathable material with a constant relative humidity of 50%, creating a healthy environment in which to live and work; and its transformation into a building material is realised without any chemical processes and produces no chemical or industrial waste. Earthen architecture offers crucial advantages for a sustainable future and the sustainability of the planet (Doat, Hays, Houben, Matuk, & Vitoux 1996) (Norton 1997) (Conti 2007) (Rakotomamonjy: 2006).

It is the revival of identity that will give us back what we lost through the negative attitude towards indigenous black people. The racist discourse started early on in South Africa and went on to be refined into a way that increasingly denied indigenous knowledge, which then lay dormant in urban areas because of official regulations, like these of 1915, which required that “… each tenant shall erect a decent Cottage … and whitewash it at least once a year. No Kafir or Beehive huts will be allowed” (Rodriquez & Pettus 1990). It was these attitudes that put an end to our valuing our customs, forms and cultural ways of knowing and being.

Houses in McGregor

Houses in McGregor

As a result of the political economy of knowledge production and textbook publishing in the world today, educational institutions tend to teach the superiority of the economic processes and political systems of western, modernist society. There is, in consequence, an emphasis on technical answers to social and environmental problems. The energy and vitality and creative use of space found in informal settlements must be a lesson to us in recognising our ability to create our own settlements.

Hassan Fathi (1986) said: “it is this population that has an intimate knowledge of how to live in harmony with the local environment. Thousands of years of accumulated expertise has led to the development of economic building methods using locally available materials, climatisation using energy derived from the natural environment, and an arrangement of living and working spaces in consonance with social requirements. This has been accomplished within the context of an architecture that has reached a high degree of artistic expression.”

While attending the 10th International Conference on the Study and Conservation of Earthen Architectural Heritage, Terra 2008, held in Bamako, Mali, in February 2008, I saw people wearing traditional clothes and creating their own traditional homes and workplaces.

Segou, Mali

To me, this connoted pride and the giving of value to those aspects of ourselves through which we sustain our sense of identity.

Djenne, Mali

Djenne, Mali

The past few decades have witnessed the evolution and enormous advancement of earthen architecture through international conferences, training initiatives and the creation of national and international committees on all the aspects of natural and earth building technology. The literature is vast. Architects, archaeologists and conservation practitioners, academics and scientists around the world, meet regularly to discuss chemistry, soil science, seismology, hydrology, structural engineering, archaeology, sociology and sustainability, biodeterioration, wind and water erosion, mineralogy, clay and soil science and chemistry and their effect on earthen structures.

Current examples are VerSus 2014, an International Conference on Lessons from Vernacular Heritage for Sustainable Architecture, whose conference themes are the study of vernacular architecture and its mechanisms for sustainability, the conservation and restoration of vernacular architecture and, most importantly, the application of sustainable lessons of vernacular heritage to contemporary architecture. Mediterra 2014, the second conference of Earthen Architecture in the Mediterranean Region, and ResTAPIA 2014, the second conference of earthen architecture conservation in general and rammed earth conservation in particular, are both being held at the VerSus 2014 Conference, from the 11th to the 13th of September 2014 at the Universitat Politècnica De València in Spain.

The use of earthen architecture upholds traditions and recognises the human ingenuity, used for 11000 years, to adapt the environment for human needs. These ancient ways of building form part of our culture, give depth and quality to our lives, and need to be acknowledged, revived, resuscitated, given status and a place in our history and architectural books. The best way of reviving and valuing them is to involve women, youth and men in South Africa, who possess all the qualities needed to build their own sustainable natural and earth centres and housing.

References

Conti, A.P. 2007. Villa Ficana in Macerata, the restoring work of a raw earth quarter. In: Fourth International Adobe Conference of the Adobe Association of the Southwest. AdobeUSA.

Doat, P., Hays, A., Houben, H., Matuk, S. & Vitoux, F. 1991. Building with Earth. The Mud Village Society: New Delhi.

Fathi, H. 1986. Natural Energy and Vernacular Architecture. The University of Chicago Press: Chicago.

Houben, H. & Guillard, H. 1994. Earth Construction: A Comprehensive Guide. Intermediate Technology Publications: London.

Norton, J. 1997. Building with Earth. A Handbook. Intermediate Technology Publications: London.

Rakotomamonjy, B. 2010. Conservation of Immovable Cultural Heritage in Sub-Saharan Africa.. CRAterre-ENSAG: Pont du Claix.

Rodriquez, A. & Pettus, K. 1990. The Importance of Vernacular Traditions. APT Bulletin. Vol. XXII: np.

All photographs are by the author.

Read this for more on the Djenne Mosque, Mali.

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Lesley FreedmanLesley Freedman graduated as an architect from the University of Cape Town. She restored an historical area of Cape earthen architecture, recording the process in the book Bokaap: Faces and Façades, travelled and then worked as Manager: Architectural Heritage Landscape for the South African Heritage Resources Agency. Through Heritage Management Planning for the sites of Mandela in the Eastern Cape; studying at CRAterre (International Centre for Earth Construction), France, visiting Mali; and attending earth building courses, Lesley discovered that sustainable settlement is still practised by rural South Africans, and by a third of the world population. She established the Whole Earth Building Foundation, registered as a Non-Profit Organisation in 2012. Its Mission is to provide vocational training and livelihood skills in sustainable building and food security technologies within the Permaculture paradigm. The foundation is lobbying for National Codes of Practice for Earthen Structures to be incorporated into South Africa’s Building Codes.

 

 

 

 

Natural Building in the Architectural Curriculum

The first time I made cob I was knee deep in trouble, there was no way of ever leaving this muddy business again. I simply love the smell and feel of wet earth being mixed. I guess it started when I lived in Prince Albert as a 5 year old and mixed “chocolate milk” in the empty-from-plants-but-not-from-soil flowerpots on our big stoep. My sister and I had to do it quietly and secretly, since my mom did not really appreciate us drinking the soil and water mixtures………….. (In that same garden we had plenty of chickens and ducks, figs and apricots, what a great place for a child to live.)

Currently, I try to impart my love of earth building to my students at the Cape Peninsula University of Technology (CPUT). If possible we have an actual physical experience of working with earth and at other times it might be more theoretical knowledge, but applied in design and technological projects. Studio projects that deal with earth technology have become an integral part of the education in our Architectural Technology Department.

What interests me now, are ways in which natural building methods are both taught in the architectural curriculum and expressed in a contemporary manner.

Within the architectural education realm, I love Ithuba Science Centre, which was designed and built by students of the Faculty of Architecture of the RWTH Aachen University.

leon krige 1

Design-build projects are of special interest to me and are defined within the architectural curriculum as “essentially the full-scale investigation of the built form. The typologies of projects are varied, but share the characteristic that it typically gives students the opportunity to engage in a project from design to actual construction” (Delport and Perold 2012).

The project embodies for me the essence required in an architectural student project. It is real, hands-on, design-build, incorporates natural building methods, contributes to a real need in a community and does all of this in an elegant architectural manner.

leon krige 2

The Ithuba Science centre is part of the Ithuba Skills College, which is in Montic just outside of Johannesburg. The College caters for students from disadvantaged backgrounds and teaches them “English and Natural Sciences, but also practical basic skills like bricklaying, carpentry, sewing or electrical fitting during a five-year training”. (Faculty of Architecture RWTH Aachen University 2014)

leon krige 3

The light steel frame of the Science Centre was erected first and it was then filled in with a straw/clay mixture, creating a highly insulated monolithic wall according to traditional German practices. The mixture was placed into formwork which was moved upward as the work progressed. The building has large roof overhangs to protect and shade the walls and the roof structure is separated from the walls to let hot air out. (Designboom 2013)

leon krige 4

The Departments of Building Typologies and of Structures and Structural Design of The Faculty of Architecture supervised the project as part of their design-build program. A full construction booklet is available as well as a short video of the construction.

Students thoroughly enjoy hands-on, design-build work and work with more enthusiasm than on traditional studio bound projects. (Sara 2006) Where this practical work has meaning in both environmental and social contexts, the learning becomes incredibly relevant.  The more this type of work is integrated within the architectural curriculum, the bigger influence education will have on future practices within the architectural and building industry.

References

Delport-Voulgarelis, H and Perold, R. (2012). Creating a New Curriculum. ARCH SA Journal of the South African Institute of Architects. Issue 58. (Nov/Des 2012). p. 50-51.

Designboom. (2013). s2arch and RWTH aachen university build a new school in south africa. [Online]. July 2013. Available from http://www.designboom.com/architecture/s2arch-and-rwth-aachen-university-build-a-new-school-in-south-africa/. [Accessed 24 Feb 2014].

Faculty of Architecture RWTH Aachen University. (2014). Student-constructured-projects Ithuba Science Centre. [Online]. August 2012. Available from http://arch.rwth-aachen.de/cms/Architektur/Wirtschaft/Projekte/~nvv/Selbstbauprojekte/lidx/1/ . [Accessed 24 Feb 2014].

Sara, R., 2006. Live Project Good Practice : A Guide for Live Projects, Available at: http://www.heacademy.ac.uk/assets/cebe/documents/resources/briefingguides/BriefingGuide_08.pdf.

All photographs by Leon Krige who granted permission for the use thereof.

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Winning the AJ Writer’s Award

Don’t underestimate natural buildings… The Great Mosque of Djenne is built entirely out of mud and has been standing for a long time. It forms a part of Djenne heritage, but also daily life as a working mosque. And, when the whole community is part of sustaining and maintaining a mud building in this way, the building also contributes to social cohesion.
This is such an important lesson to remember when doing development work in southern Africa. When you eradicate mud buildings, it’s not just a building that you get rid of, but a social history and a chance for people to contribute to their community.

Arub Saqib

AJ1 IMG_1777

My article on Djenne’s main Mosque has been published in the Architect’s Journal this week and shortlisted for the Writer’s Awards

  • — A Primitive Art

    Primitive. When most of us think ‘African art’, this is the word that springs to mind. African architecture is a subject detached further still from our understanding. An unrecognized art, architecture in Africa is usually observed through flickering documentaries and fading books categorized under anthropology or archaeology; studied in fleeting glimpses under subheadings of politics, colonialism and oil – interests that make mention of buildings only as a backdrop for more pressing concerns circling the continent.

    Yet the architecture of Africa is perhaps richer for the fact that it has remained dormant in our eyes, slipping away from our conscience like a half-remembered dream. Different in every sense of the word, from the materials to the form and construction, this indigenous and localised architecture remains…

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Using natural materials: A comparison

by Malcolm Worby

Using natural materials for construction of dwellings and community buildings, is the oldest method of building since humans moved away from caves. In fact, more people in the world live in houses built of natural materials, than any other type of building material. It is therefore the most common method of building in the world.
There are many different types of natural building materials, and to describe and go into detail about each one would only serve to confuse many who are unfamiliar with natural building practices, as some are only applicable to certain areas of the world. So, in order to keep things simple, the more popular, and commonly known and used types, are outlined below, describing the basic methods of building with the material, along with its advantages and disadvantages. This is by no means meant to be comprehensive, and is intended solely to explain the basics to those who are unfamiliar with the different types of building and material. There is of course far more detail, and also other options of how to build than is outlined below, and it is hoped that anyone who having read this information, and is interested in pursuing building using natural materials will seek a professional to assist them to make the right choices.

ADOBE (MUD BRICK)
Adobe bricks comprise of a mixture of clay, coarse sand, fine sand, silt, and water, (the ideal clay content is no more than 20% of the mixture) which is placed in a form made to the size of the bricks required, and then removed to allow the bricks to bake in the sun until hard. A binder such as straw is added only if the clay content is low. The dried bricks are built on a solid foundation, ideally stone, built to a minimum of 200mm above ground level, which also acts as a ‘Damp Proof Course’ as it raises the adobe bricks wall from absorbing moisture from the ground. A similar clay-sand-water mix as used to make the bricks is used as mortar between the adobe bricks. Fairly large roof overhangs (600mm minimum) help prevent the walls being eroded over time, and on the north wall it helps keep the building cool in the summer. Usually a 2-coat earthen or lime plaster is applied as a final finish. Adobe wall structures lend themselves to having load-bearing walls, however, a wood or concrete ‘ring beam’ is recommended to support the roof structure.
The soil for making adobe bricks is usually of local material, and ideally from the property itself. This therefore makes adobe one of the most affordable building technologies, and is often completed without the use of engineers or architects, hence the term ‘non-engineered construction’. The walls are usually a minimum of 250mm thick for a single storey and 600mm double-brick thick for added thermal mass, and for two-storeys. Ideal areas for building with adobe would be temperate climates with hot and cold seasonal swings, cold climates, and hot dry climates which fully utilise the thick thermal mass for heat storage in winter, and for cooling during the summer. In hot and humid climates, narrower thickness walls could be used, providing sufficient roof overhang is provided for shade.

Advantages:
• High thermal mass is very energy-efficient in both summer and winter, and ideal for passive solar heating and cooling. Indoor temperatures vary only about 5 degrees between summer and winter (17-22 degrees), making it naturally cool in summer and warm in winter.
• Environmentally friendly: Low carbon footprint and embodied energy
• Ideal material for owner builders and unskilled labour
• Relatively inexpensive for a long lasting building
• Lends itself to creative and free-form walls
• Rondavel (round) type Adobe buildings are capable of withstanding seismic activity
• Fireproof
• Excellent sound insulation
• Can easily be built up to 3 stories
• Can be recycled
• Approved by many local building departments.

Disadvantages:
• Fairly labour intensive
• Obtaining a bond from lending institutions is extremely difficult
• Adobe cannot be laid during very wet or freezing weather
• Insects, notably termites and small rodents can burrow into the walls weakening them. The use of dung in the mud mix, and lime plaster can negate this problem

COB
Cob, like adobe, is also comprised of a mixture of clay, coarse sand, fine sand, silt, and water; it also uses a binder of fibrous or organic material such as straw, or dung. The cob once mixed, can either be used ‘as is’ and installed in ‘lifts’ of about 600mm, or can be rolled into balls about 200mm in diameter. The building is a process of laying the straw-clay mixture or balls in layers on top of the foundation walls, which are built ideally with stone, to a minimum of 200mm above ground level. The walls start wide at the base (600mm+) and taper in as one builds up. Each layer of cob must be allowed to dry before laying the next. As with adobe, large roof overhangs (600mm minimum) help prevent the walls being eroded over time, and on the north wall it helps keep the building cool in the summer. Cob wall structures, due to their width, lend themselves to having load bearing walls, however, a wood or concrete ‘ring beam’ is recommended to support the roof structure. Usually a 2-coat earthen or lime plaster is applied as a final finish. The soil for making cob and cob bricks is usually of local material, and ideally from the property itself. Therefore cob is also one of the most affordable types of building material, and can be built often without the use of engineers or architects, as ‘non-engineered construction’. Ideal areas for building with cob would be temperate climates with hot and cold seasonal swings, cold climates, and hot dry climates which fully utilise the thick thermal mass for heat storage in winter, and for cooling during the summer. In hot and humid climates, narrower thickness walls could be used, providing sufficient roof overhang is provided for shade.

Advantages:
• High thermal mass is very energy-efficient in both summer and winter, and ideal for passive solar heating and cooling. Indoor temperatures vary only about 5 degrees between summer and winter (17-22 degrees), making it naturally cool in summer and warm in winter.
• Environmentally friendly: Low carbon footprint and embodied energy
• Relatively easy to build for owner builders and unskilled labour
• Relatively inexpensive for a long lasting building
• Lends itself to free-form walls
• Excellent sound insulation
• Cob buildings are capable of withstanding seismic activity, but must have a ring beam.
• Fireproof
• Can easily be built up to 3 stories
• Cob can be easily recycled

Disadvantages:
• Labour intensive
• Relatively slow to build
• Obtaining a bond from a lending institution is very difficult.
• Cob walls cannot be laid during wet or freezing weather
• Insects, notably termites and small rodents can burrow into the walls weakening them. The use of dung in the mud mix, and lime plaster can negate this problem

RAMMED EARTH
Rammed Earth construction is done by using a mixture of sand, gravel, clay (the proportions depend on the available soil), and water. The mixture is placed into formwork made of plywood supported by steel frames (or similar), placed on top of the foundation wall. The amount of mixture placed in a form at a time, known as a ‘lift’, is typically about 150mm deep, which is then compacted either manually, or by a pneumatic backfill tamper. This process is repeated until the desired wall height is reached. Door and window openings are created by using formwork, with lintels placed on top of the forms prior to compacting. The final result is a sculpted earth wall of exceptional strength. A stabiliser, preferably lime, but cement can be used, can be added prior to mixing, and is typically between 5% -13% of the mixture. Note: If cement is added as a stabiliser, a rammed earth wall 300mm thick, will have more cement content than a 115mm wide concrete block wall, and therefore the carbon footprint and the embodied energy is increased dramatically. For more creative builders, Rammed Earth offers the opportunity to mix colours of soil and when the lifts are done in different colours, it provides ‘stratification’ in the walls. This process when sealed with beeswax or similar, provides a beautiful finish with minimal maintenance. The thick earth wall is structurally very sound, but it is recommended that a wood or concrete ring beam be installed at the top of the walls. Ideal areas for building with rammed earth would be temperate climates with hot and cold seasonal swings, cold climates, and hot dry climates which fully utilise the thick thermal mass for heat storage in winter, and for cooling during the summer. In hot climates, it is essential that the walls are shaded at all times.

Advantages:
• Low carbon footprint and embodied energy.
• The thermal mass is ideal for passive solar heating and cooling.
• Rammed earth walls are extremely strong
• Excellent sound insulation
• Fire proof
• Insects and rodents are not a problem
• Does not need to be plastered
• Can withstand seismic activity providing it has a concrete ring beam.

Disadvantages:
• Rammed earth walls are very labour intensive.
• Building the walls is a slow and precise process.
• The formwork adds considerable cost.
• Obtaining a bond from a lending institution is very difficult.
• The walls cannot be built during wet or freezing weather
• Difficult to recycle

SANDBAG
Sandbag construction consists of lightweight plastic bags filled with sand or other earth mixes. Ideally the soil or mix is locally available on site. Typically sandbag construction utilises the pillar and beam type of structural framework construction, whereby the full bags are used as ‘in-fill’ by laying in courses, on a foundation wall, between the pillars. If pillar and beam construction is not used, the building will need to have curved walls to create added strength. Once the walls are completed, typically chicken-wire is then attached to the sandbags, which will allow the walls to be plastered, ideally with lime plaster. Sandbag walls are relatively quick to build, and due to the pillar and beam framework, they are also strong, and relatively inexpensive. Sandbagging requires very little water especially compared to adobe, cob, or rammed earth, which can be an important factor in some areas. Sandbag walls are also a viable option for constructing temporary buildings, as the materials are mostly reusable. The thick walls offer a good thermal mass which helps regulate the interior temperature of the building during both the summer and winter months. Ideal areas for building with sandbags would be temperate climates with hot and cold seasonal swings, cold climates, and hot dry climates.

Advantages:
• Relatively low carbon footprint and embodied energy.
• Sandbags can be reused or recycled
• Strong structures are erected quickly using pillar and beam construction with sandbag ‘infill’
• Minimal water needed for construction.
• Good thermal mass for regulating internal temperatures
• Excellent sound insulation.
• In rural areas, ‘Mealie’ bags can be collected and recycled as sandbags.
• Services can easily be added during the construction phase

Disadvantages:
• Labour intensive
• Care must be taken to prevent water penetrating through to the sandbags
• Sandbags are often made of plastic and are imported from China, which increases its environmental footprint, and embodied energy. Locally made bags are available, but are more expensive.
• Pillar and beam technology using steel, cement blocks, and wood from non-sustainable forests, are not environmentally-friendly
• Walls must be plastered.
• Obtaining a bond from a lending institution is very difficult.

STRAW BALE
The straw bales used for building must be of grain stalks (oats, barley, wheat, etc), as opposed to hay bales, which are made from grasses. The use of straw bales as a building material is very environmentally-friendly, as the straw if not baled, is typically burned by the famers after harvesting, creating tonnes of air pollution. Building with straw bales either utilises the pillar (or post) and beam type of construction, with the straw bales used as ‘infill’, or the straw bales built as a load-bearing wall. In the load-bearing wall method, a wood roof or top plate is installed covering the full width of the top of the wall, which in turn is attached to the foundation, typically with wire straps, on approximately 1200 centres. The top plate acts not only as a bearing plate, but also as a ring beam, distributing the roof load evenly along the walls. Window and door openings will need to be structurally framed in with wood in both methods. The walls when completed, and the roof is installed, are typically covered with chicken wire, and then plastered with either mud or lime plaster on the exterior, and mud, lime, or gypsum plaster on the interior. It is recommended that there is a sufficient roof overhang to help prevent water saturation during heavy rains.
Straw bale building, due to its high insulating value, is most beneficial in hot, dry desert climates, high desert climates with large daily temperature swings, cold climates, and temperate climates which have relatively hot summers, and cold winters.

Advantages:
• Energy efficient, as straw bales have a very high insulation value.
• Straw bales are produced from a waste product that is bio-degradeable.
• Can be built using unskilled or semi-skilled labour.
• Not as labour intensive as other natural building methods.
• Structurally strong
• Excellent sound insulation
• Relatively inexpensive material to purchase

Disadvantages:
• Straw bale walls are susceptible to mould and deterioration unless protected from moisture, and allowed to ‘breathe’.
• No thermal mass for passive solar heating and/or cooling
• Transportation increases the embodied energy/carbon footprint, and also the cost, unless building on a farm growing cereal crops.

As published on Enviropaedia under the title Green Building: Using natural materials

Disclaimer

Malcolm WorbyMalcolm Worby studied at Bristol Polytechnic in the UK and has had his own award-winning architectural design firm ‘Malcolm Worby Designs’ for over 30 years specialising in natural, sustainable, and environmentally friendly building. He now specialises in providing consulting services for natural and sustainable building projects, including mud brick (adobe), straw bale, sand and earth bag design and building, passive and active solar heating and cooling, photovoltaic (PV), grey water recycling, rainwater harvesting, and composting toilets. He has designed buildings in various parts of the world including the USA, UK, South Africa, Mexico, and the Netherlands, and has worked on low income affordable community-build projects in South Africa, Malawi, Mozambique, South Sudan, Uganda, Zambia through his Non-Profit Organisation ‘Homeless And Poor People’s Initiative’ (HAPPI).

Two heads are better than one… Networking Event: The Better Living Challenge

If you’ve always wanted to get involved in solving South Africa’s housing problem, meet some people that share your creative vision and change-maker attitude at a meeting hosted by the Cape Craft and Design Initiative.

Speakers this month: The Better Living Challenge

Date and time: 5 MARCH  2014

Time: 13h00 to 15h00

Venue: CCDI Creative Enterprise Training Unit,
2nd Floor, 37 Barrack Street, The Fringe, East City, Cape Town.
(Entrance next door to The Field Office Café. Between Buitenkant and Harrington Streets).

For more information, visit our News page… And, remember to please contact us to send us your news about natural and sustainable developments in Africa.