Q&A with Paul Marais, award-winning architect specializing in rammed earth

First off, congratulations on winning the Afrisam-SAIA Award for Sustainable Architecture + Innovation for Sustainable Product/Technology for your design of the rammed earth Otto cottage in Maun, Botswana. 

Thank you, I am very pleased for recognition of this off grid, rammed earth building , where I designed and built the house, energy & water systems and sewerage.

The award-winning rammed earth Otto cottage in Maun, Botswana. Designed and built by Paul Marais. Photo courtesy of Paul Marais.

The award-winning rammed earth Otto cottage in Maun, Botswana. Designed and built by Paul Marais. Photo courtesy of Paul Marais.

How did you first get involved in natural building?

I have been always interested in natural buildings and as a student studied natural building in Malawi and Zambia.  I have travelled a lot in remote Africa and have an interest in indigenous architecture which is both material and energy efficient.  Continue reading

Guest post: Rammed earth on the rise

By Mary Anne Constable

This post first appeared on Earthworks Magazine in April 2016. We are re-posting it here with the permission of  Young Africa Publishing and author Mary-Anne Constable.

Rammed earth in Botswana

House Freeman is cool in the hot Botswana desert thanks to an evaporative cooling system, which draws air over solar powered sprinklers, a living roof and thick, thermally efficient walls. The shuttering was reused in, for example, the roof, so nothing was wasted.

Of more than twenty different types of earth construction techniques, rammed earth has been lauded for its durability, sophisticated environmental performance and striking earthen beauty.

Rammed earth construction in South Africa has generally been stigmatised as a substandard and primitive building construction method reserved ‘for the poor’. Yet it is now gaining popularity for community social projects, as well as among wealthier clients. Although a building standard is yet to be formalised in South Africa, the rammed earth industry is established in many African countries, Europe, United States and Australia. This means plenty of expertise and established international building standards already exist and this construction method is now far removed from its primitive roots.

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From the ground up ~ approaches to building a foundation for your natural building

Foundations for conventional building have, to a large extent, a one size fits all approach regardless of the type of ground you are building on i.e. a concrete and steel foundation that works equally well on all types of earth and varies only slightly in its design. It requires little thought and has been proven to be effective. The cement in concrete provides the compressive strength, and the steel tensile strength to resist cracking. It does however come at a cost to both your pocket and the environment.

When building with earth your foundation needs to be well considered as the integrity of your building rests here. Decisions you make about your foundation depend on the materials you have available, the type of ground you have to build on and what carbon footprint you want to leave. The goal should be to create foundations that are hard enough, move uniformly and resist cracking for the walls above it. Foundations will always have a higher Mpa value than the walls, however it does not need to be excessive. A 4 Mpa foundation is sufficient for a 1.6 Mpa mud-brick wall, which most types of foundations are suitable for. Furthermore, if after levelling the site the undisturbed earth is hard enough, foundations may well be unnecessary.

There are several strategies for foundations depending on the type of ground that you are building on. In this blog post, I discuss the four types of ground, (1) uniformly hard, (2) uniformly soft, (3) hard and soft, and (4) clay, their challenges and several strategies you may incorporate into your design. The discussion is quite technical in some areas so I recommend that you read my three-part series on understanding earth first. Continue reading

First course of 2016

Poster 04_2016 sml

How to incorporate passive solar design in your building, using thermal mass and insulation.

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Passive solar design is the starting point of sustainable building. Once one understands the basic principles of using the abundant natural renewable resources at our disposal we become more creative in our approach to design, more in tune and observant, reconnecting us with the natural rhythms that surround and sustain us, if only we would pay attention. Sustainable buildings save money, reduce your carbon footprint and provide a healthy living environment, transforming buildings from consumers of energy to producers and forging buildings that meet our needs.

From a permaculture perspective, incorporating these aspects into the design of your home are excellent examples of several permaculture design principles. To mention the most obvious: Observing and interacting with your environment to make the most of the sun’s migration, catching and storing energy, using and valuing renewable resources and services, integrating functions and elements rather than segregating them and obtaining a yield from the planet’s most abundant energy source, the sun.

Passive Solar Design uses the energy provided by the sun and stored in the earth. First we need to look at how this energy is utilized by defining insulation and thermal mass and then look at the strategies of how to incorporate them into our designs.

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The dynamic qualities of African Vernacular Architecture

In this guest post written by Jon Sojkowski, he chronicles common misperceptions of African vernacular architecture and how it is being abandoned for the status that comes with living in conventional Western style buildings. He asks whether these modern materials are truly better than the vernacular options.

By Jon Sojkowski

African vernacular architecture is a subject that has had very little attention. The lack of documentation and available data on the internet has led to a severe misunderstanding of a type of architecture that a large percentage of the population in Africa living in on a daily basis. The lack of data has led to negative perceptions regarding African vernacular architecture, mainly that it is temporary, primitive or for the poor. Most people, when they think of a mud hut, get an image of a dilapidated mud structure which is quite small and has a thatch roof. Sadly, this perception exists both inside and outside the African continent, but it is simply not the truth. Continue reading

CPD accredited natural building course: Materials and techniques

We’re excited to announce the first course of the year will be taking place from 26 April – 2 May, at Wild Spirit Backpacker’s lodge in the beautiful Nature’s Valley. Email naturalbuildingcollective@gmail.com to book your spot!

CPD accredited Natural Building 7 day course_April_WS