The final Perspectives on Architecture talk in 2013 came from Jo Ashbridge, 2012 RIBA Boyd Auger Scholarship recipient, on Tuesday 12th November. At the time of receiving the award she was already in Bangladesh working with a local, shelter related organisation called Simple Action For the Environment (SAFE) in collaboration with Engineers Without Borders (EWB-UK).

Powerpoint from ‘Earthen Architecture in Resource Limited Settings:  A Bangladesh Case Study’

Below is a transcript from the talk:

“The research focuses on earthen solutions within a disaster risk reduction framework in areas across Bangladesh; areas that are subject to an array of water related concerns and can be broken down into three phases:

  • Phase 1: Documentation and analysis of earthen vernacular and shelter provision by non-governmental organisations (NGOs) and international agencies
  • Phase 2: Research, development and testing of modest improvements to earthen construction
  • Phase 3: Design of a prototype house based on these findings, which utilises earth as a primary building material

 

One of the most important drivers was the participatory approach, to include the local population in all aspects of the work and use a range of human centred methods to not only gain a real insight but also ensure transparency and in the end ownership of the intervention.

Bangladesh is a relatively new prospect for many and therefore it is important to understand current conditions:

  • Bangladesh is situated in southern Asia, bordered by India, Myanmar and the Bay of Bengal
  • The terrain, unlike its neighbours, is relatively flat alluvial plain with hilly areas to the southeast
  • It features a tropical climate with three primary seasons, one being monsoon.  However if you speak to many farmers they will tell you that there are in fact six distinct seasons relating quite specifically to rice production.
  • 53% of the country is arable land and although over half the GDP is generated through the service sector, 45% of Bangladeshis are employed in the agricultural sector with rice production taking centre stage
  • It is one of the most densely populated countries on the planet, with 164 million people occupying a landmass of 144,000 sqkm.  The World Bank data records 1,174 people per sqkm compared to 259 in the UK.
  • The population is 90% Muslim, although I lived for much of my time in a predominantly Hindu village and the national language is Bangla
  • Over half the population is living on less than a dollar a day, which effectively means a lack of access to opportunities such as durable housing, electricity, safe water and sanitation to name a few
  • Bangladesh is a country at the forefront of climate change; its low lying terrain means it is vulnerable to flooding.  A recent report by the Intergovernmental Panel on Climate Change (IPCC) indicates that by 2050 two thirds of the southern belt will be under water.  This of course means a loss of habitat and livelihoods but is also a nod to the devastating knock on effects of mass migration.

 

When you look at an issue such as earthen architecture and its role and relevance in society it cannot be studied in isolation.  Geography, society, economy, politics and environment all play a part in how and why earthen architecture is still prominent and whether it has a future.

The study looks at three divisions (Bangladesh has seven in total).  In the northwest, Rangpur is famous for its rice production.  It is a relatively rural region which lies in one of the highest earthquake prone zones in the country and districts such as Dinajpur suffer from particularly strong winds during September and October.

Along the southern coast, Khulna and Barisal divisions.  This is shrimp farming country, which in itself is causing severe repercussions for the environment.  The coastal districts frequently experience tropical cyclones and storm surges, the effects of Cyclone Sidr in 2007 still felt today.

Earthen architecture and construction can be sustainable, low cost and beautiful, but is it relevant in such a climate?

Wintertime in Bangladesh, particularly in low income communities is a real concern.  Temperatures drop as low as 5OC and hundreds are estimated to die every year in a large part due to inadequate housing.  More and more you see NGOs incorporating the distribution of blankets within their responses.  The thermal mass of earthen solutions keeps spaces both cool during high summer and warm during winter.  A simple earthen plaster applied to a loose bamboo weave wall can also provide a level of protection against wind, rain and abrasion.

Humidity levels in Bangladesh are recorded to reach 90% in July.  The porous nature of earthen walls means that they absorb and release water and therefore have the potential to act as a modulator for indoor humidity.  Many earthen solutions do not require expensive tools or technical knowledge, so again are potentially suited to low income demographics.

Earthen solutions complement other sustainable materials such as bamboo, jute and coconut timber which are all native to Bangladesh.  And, earth is potentially free, either harvested from your own plot or less legally from government land.

So far so good.

So what are the challenges to using this material?

Well, although the tools and techniques may appear relatively simple, there is a need for local knowledge of climate, soil suitability and weather patterns.  Earthen solutions work best when they are not in isolation, when they are complemented by design features such as adequate footings and roof overhangs.  Without water resilience measures or stabilisation techniques there is a risk of erosion and impact.  This then leads to ongoing maintenance requirements which can add an additional burden to the daily tasks of many low income families.

Poverty Economics, written by A. V. Banerjee and E. Duflo has become a key text in my life:

“Our real advantage comes from the many things that we take as given.  We live in houses where clean water gets piped in – we do not need to remember to add Chorin to the water supply every morning.  The sewerage goes away on its own – we do not actually know how…

We have no choice but to get our children immunized – public school will not take them if they aren’t and even if we somehow manage to fail to do it, our children will probably be safe because everyone else is…

And perhaps most important, most of us do not have to worry where our next meal will come from…”

For better or worse we live in a somewhat paternalistic society.  For many of the communities I was able to visit the list of daily tasks is momentus…  elements of our lives which we take for granted.  If we could lift those burdens, such as the necessary maintenance of earthen walls, imagine what could be achieved with the time saved?

The next questions are of course:

Is earthen architecture and construction commonplace in Bangladesh?  What earthen solutions are used?  Which techniques are favoured and which are not?  Which demographics use this material and what are their housing visions for the future?

The project focuses on three divisions and although there were differences in earthen vernacular across these divisions I would argue that it is very much a material used within low income communities and people really do know how to use it.

There are essentially three categories: plinths, walls and plasters.  In all categories the tendency is to use a sticky mud, essentially a simple mix of earth and water (sometimes with the addition of animal dung or fibres such as straw).  How sticky the mixture is depends on the individual craftsman or artisan and how they like to use it.

In all three divisions you see earthen plinths and the latest Bangladesh Bureau of Statistics (BBS) Populations and Housing Census indicates 74% use of earthen floors.  Plinths elevate residences above standing water due to monsoon rains and help to protect individuals and their assets during flash floods.  This technique is also seen for animal shelters.  They are compacted in a variety of ways, using local ramming tools and there is often little external protection which is a real problem in areas where flood waters are yet to recede.

One village I visited in Tala union of Khulna division had been underwater for nine months, we had to row boats to reach people’s front doors, new bamboo bridges were being created for general access and certainly there was a real issue with undercutting.  Life however does go on and ingenuity is witnessed at every corner.

Earthen walls vary, from thick adobe structures where sticky mud is thrown in layers rather than rammed to sundried earthen blocks laid with earthen mortar and rammed earth walls.  Earthen plasters also feature in all three divisions.  In Dinajpur basic single storey bamboo frames with split bamboo weaved panels are plastered, in Khulna and Barisal you see a lot more jute and coconut timber again plastered to a smooth hand finish.  Other earthen based solutions include fired products such as bricks, terracotta roof tiles (which are sadly out of fashion) and clay products which support daily life.

One of the most intriguing aspects talking to residents in the various communities I was fortunate enough to visit was their perception of earth as a construction material.  It is very much seen as a ‘poor mans’ material, as are other natural materials such as bamboo.

An interesting example is the Practical Action prototypes project run in collaboration with RESET.  Four one room shelters were designed and built within one community of Shyamnagar.  The designs were standardised but the materials differed.  The idea was to document the environmental performance of each and the perception of beneficiaries.

When you walk into the houses topped with terracotta tiles or golpata leaf it is noticeably cooler than walking into the two that feature corrugated iron (CI) sheets.  In fact those are quite unbearable during the heat of the day.  Talking to all of the beneficiary households everyone responded that they would prefer a brick house with CI sheet roof rather than an earthen wall or plastered structure with terracotta tiles.  They were fully aware of the comfort issues, but believed longevity to be important.

In a society which relies heavily on status there is a real desire to upgrade houses with more ‘durable’ and expensive solutions.  This stage of the project led to many discoveries about the current use of earth, past practices and future ideas.

So is earth a primary building material in the shelter responses of NGOs?

One of my first questions to head quarters and field staff when I was arranging my logistics and site visits was, “Does earth feature in your design solution?”.  Most of the time I was met with a no and prior to my analysis this seemed a missed opportunity.  Although in most solutions I couldn’t say earth was a primary building material, in all those I visited it did feature.

In the NARRI design, the largest shelter programme to be rolled out across Bangladesh, the field staff were working with residents to promote plinth embankments to help support the brick retaining walls which had been designed only using a single leaf…  the lateral pressure has caused some failures.

BRAC, the largest NGO on the planet, provided 43 cyclone resistant houses on stilts in Adarsha Gram, one of the most vulnerable areas of Bangladesh along the southern coast.  They worked with local craftsmen to improve upon handmade terracotta tiles, celebrating this solution which was once commonplace across the region.

To make a house a home, some beneficiaries had plastered their houses or infilled junctions to achieve a more watertight finish.

Earth doesn’t feature high on the agenda of NGOs, and this is largely due to time constraints, logistics and potential savings with manufacture of parts off site and bulk purchase.  However, as these shelter responses are minimal in the whole scheme of a country that is growing at such a rapid rate there is a real opportunity to work with populations to support them in improving the quality and longevity of their existing earthen residences.

In phase two and three I worked with SAFE to develop and test such improvements.  This included field tests to identify locally sourced and freely available natural additives that could compete with synthetic alternatives for use within earthen plasters.  Cement, lime and bitumen are an option to improve water resilience but low income households are often unable to afford these additions.

Not to go further into detail but we were able to identify a local tree mulch that performed wonderfully against a 5% cement and SAFE are currently creating a tree nursery to reintroduce this species back into the landscape.  For more information download the publication, http://issuu.com/joashbridge/docs/water_resilience_of_earthen_plasters

Secondly we built a prototype house to directly test a range of earthen solutions.  This house was designed with the beneficiary household and community and the work supported by building for safety workshops, community meetings and design consultations to disseminate ideas and offer a platform to discuss the solutions.

Again, the participatory approach, design, techniques and handover process could be a talk in itself, but to give a brief overview it is a double storey scheme with a raised brick plinth and compacted stabilised earth floor.  The ground floor walls are constructed with compressed stabilised earth blocks (CSEBs), rammed using a locally made machine featuring recycled bicycle components.  A series of stabilised earthen plasters allow the walls to breathe and although the second storey is predominantly constructed with bamboo the upper floor is a stabilised earth, thrown wet.

With the funding available, we were only able to provide one prototype but it is very much an experiment in itself and I am receiving ongoing feedback from SAFE. 

Additional financial support from friends, family and strangers enabled a holistic design response.  Although this is a prototype to test solutions it is first and foremost a home for a family of five:  Shayarani, Tarindaro, Himan, Dorithri and Bilash.  So the house is complemented with a ventilated improved pit latrine, the first latrine in this para and a designated kitchen with improved cook stove.

There is a need to work with local communities to strengthen the capabilities of individuals and families, to improve shelter construction technologies and techniques based on successful existing practices, to offer modest improvements and this includes the use of earth.  A participatory approach is just one of the many aspects needed to encourage community self-reliance rather than dependence on aid.

Architects are a luxury, engineering advice is costly.  People all over the world are building their own houses and will continue to do so.  In Bangladesh from my experience, earth is a key component of construction in areas with limited assets and it is very much part of the future of this country.

I am currently working on a publication to document the entire project.  If you are interested to know more or would like to receive a pdf once it is complete please do drop me an email (jashbridge@azuko.org) and I’ll add you to the distribution list.

The presentation includes a short video of the places I witnessed, the design process and the people that welcomed me into their homes; my life over the past 13 months in a country of true hospitality.  The accompanying song was written by one of the most famous and loved Bengali poets, Rabindranath Tagore; the first ten lines of which were adopted as the National Anthem in 1972 following the Bangladesh Liberation War.

The video is dedicated to my building team who I miss a great deal.”

Earthen Architecture in Resource Limited Settings: A Bangladesh Case Study from Jo Ashbridge on Vimeo.

All images copyright of Jo Ashbridge.

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