A brief look ahead at our natural building courses for 2018

Attend our natural building course and take the first step to a sustainable future by learning hands-on natural building skills. Learn a whole range of materials and techniques while exploring questions around sustainable living based in Peter McIntosh’s experience living off-grid since 1999.

Natural building courses in South Africa 2018

If you’re serious about building naturally and sustainably then you’ll know that each technique has pros and cons. That is why our natural building course is designed around the principles of understanding earth, how it works and does not work together. You will leave with the theoretical understanding and practical grounding of a range of techniques and materials, so that you are able to make the most appropriate decisions regarding materials and or sustainability once you are ready to begin your project.

This year, Peter will be hosting two CPD accredited courses at Jakkalskloof farm, in Swellendam. Continue reading

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Guest post: Hybrid alternative and natural building blocks at the Delft ECD (Early Childhood Development Centre)

In Delft, an impoverished township on the outskirts of the Cape Flats, local government is changing its approach to building early childhood development centres with a pioneering project showcasing a hybrid of natural building methods and up-cycled waste materials.

By Mary Anne Constable

This post first appeared on Earthworks Magazine in February 2017. We are re-posting it here with the permission of  Young Africa Publishing and author Mary-Anne Constable. 

Peter McIntosh, founder of the Natural Building Collective was the project coordinator for the alternative materials (natural and recycled) portion of the Delft ECD build.

Delft ECD_Natural building collective

The new Delft ECD (Early Childhood Development Centre) represents the first time that government – in this case the City of Cape Town – has significantly integrated alternative and unconventional building methods for the construction of a public building.

The considered design of the Delft ECD building is an example that will make an essential contribution to the development of South Africa’s youngest residents. The alternative building materials, which include both natural methods (compressed earth bricks and cob) and recycled waste materials (ecobricks, tyres, glass bottles), deviate from conventional brick and concrete, while creating a healthy environment.  Continue reading

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Announcing natural building course dates for 2017

Are you on the track with your sustainability goals? Attend our natural building course this year and learn some essential practical skills to help you on your way to living the off-grid dream.

We are thrilled to announce that both courses will be held at Jakkalskloof bio-dynamic training farm in Swellendam this year.

Dates for 2017:

  • 19 – 25 March: Natural building course: materials and techniques (7 category 1 SACAP credits) ~ Jakkalskloof farm
  •  14 October: Natural building course: materials and techniques (7 category 1 SACAP credits) ~ Jakkalskloof farm

For more information please visit our course page or send us an email at naturalbuildingcollective@gmail.com to book your spot!

natural-building-course_poster_03_2017

https://www.naturalbuildingcollective.com

First natural building course of 2016

Announcing our first natural building course for 2016! Our natural building course is comprehensive and covers a range of materials and techniques based on Peter McIntosh’s professional and personal experience working with these approaches and from having lived off-grid since 1999.

The course will be taking place at Wild Spirit Backpacker’s in Nature’s valley from 17 – 23 April. You will leave with the theoretical understanding and practical grounding of a range of techniques and materials, so that you are able to make the most appropriate decisions regarding materials and or sustainability once you are ready to begin your project.

Drop us an email to book your place and avoid disappointment.

Poster 04_2016 sml

https://www.naturalbuildingcollective.com

TERRA Award ~ first international prize for contemporary earthen architecture

The TERRA award is a collaborative effort on an international scale to enable both professionals and the general public to fully appreciate earth’s increasing popularity as a building material of high aesthetic and technical quality. 

Earth is becoming increasingly popular in contemporary architecture: hundreds of projects of high aesthetic and technical quality are emerging across five continents. This material, which has low embodied energy, is readily available and appropriate for participatory buildings. It could help provide a solution to the needs for ecological and economical housing.

To enable both professionals and the general public to fully appreciate this building material, the following partners have taken the initiative, under the auspices of the UNESCO Chair “Earthen architecture, construction cultures and sustainable development”, to launch the first international prize for contemporary earthen architecture: the Labex AE & CC-CRAterre-ENSAG Lab research unit, the amàco project, the Grands Ateliers, the CRAterre association and EcologiK/EK magazine.

Wang Shu, 2012 Pritzker architecture prize laureate, is the president of honour of this TERRA Award, the trophies for which will be presented in Lyon on July 14, 2016 at the Terra 2016 World Congress.

Context

Since its creation in 1979, the CRAterre-ENSAG Lab has been considered as the international research and training reference centre for earthen construction. It will organize in July 2016, under the auspices of the UNESCO Chair “Earthen architecture”, the Terra 2016. This World Congress takes place every four years on a different continent and will be held for the second time in Europe. It is expected to draw around 800 professionals, teachers and researches to Lyon (France).

The TERRA Award was initiated within this framework. It will be the first international prize for contemporary earthen architecture and a natural furtherance of the national award launched in 2013 in France by CRAterre-ENSAG, AsTerre and EcologiK/EK magazine.

Objective

The purpose of the TERRA Award is not only to identify and distinguish outstanding projects, but also to highlight the audacity of the project owners for choosing to use earth, the creativity of the designers and the skills of the craftsmen and entrepreneurs.
An itinerant exhibition will feature 40 buildings from all continents, constructed using various techniques (adobe, cob, CEB, rammed earth, plaster, etc.) for all types of programs: housing, public facilities, activities, and exterior and interior designs. The exhibition will be completed with lectures and workshops by CRAterre-ENSAG and the amàco project.
The search for outstanding achievements deserving of this prize and the associated exhibition will make it possible to generate the first worldwide database on contemporary earthen architecture. The resulting virtual library will be available both to the general public and professionals via this website.

Involved projects

The projects must have been completed after January 2000.
There are eight categories covering all types of programs, whether new or renovated:

  • Individual housing
  • Collective housing
  • School, sports and health facilities
  • Cultural facilities and religious buildings
  • Offices, shops and factories
  • Interior layout and design
  • Exterior design, art and landscape
  • Architecture and local development

Text from the Terra Award website.

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

Passive solar design can dramatically reduce our demands on fossil fuels and other forms of energy input, allowing our buildings to become producers and not consumers of energy and resources, supporting us in a healthier more comfortable abundant way.

DSC01797_edit 1

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.

Continue reading

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The dynamic qualities of African Vernacular Architecture

In this guest post 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

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Owner-builder journey ~ Franz Muhl: Energy flows where attention goes

In this edition of the Owner-builder journey, Franz Muhl writes about a mud brick addition to his Scarborough home: “Let me build a home from fertile materials that is beautiful and healthy to live in, have a very low footprint and would grow a forest if you left it.”

Franz 1

Five years ago, Peter McIntosh gave me +- 900 sun-baked mud bricks, for an extension to my house. Franz 3With little start up money, a trickle of income, some plans on google sketch up, a pickaxe and, most importantly, plenty of time, I finally started the process a year ago.

 

At foundation level, with the skills that I had at the time, I used clay-fired bricks and a bitumen coat for damp-proofing. Franz 4In March, I headed off to Berg-en-dal for a crash course with Peter. He traded his skills and knowledge in natural building for mine in brewing beer. To take clay, sand, water and a bit of straw in the right proportions and work it into a material for building, was a big revelation for me. Continue reading

https://www.naturalbuildingcollective.com

CPD accredited natural building course: Materials and techniques

Our natural building course is comprehensive and covers a range of materials and techniques based on Peter McIntosh’s professional and personal experience working with these approaches and from having lived off-grid since 1999. You will be empowered to be successful and make rational choices whatever the given situation.

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.

Take the first step to a sustainable future by learning hands-on natural building skills. Understand the alchemy of how different types of earth work, and do not work together, their potential and limitations. You will also explore questions around sustainable living based in Peter McIntosh’s experience living off-grid since 1999.

Email naturalbuildingcollective@gmail.com to book your spot!

CPD accredited Natural Building 7 day course_April_WS

 

 

https://www.naturalbuildingcollective.com

Understanding earth III: Plaster and mortars mixes

(Please note that in order to understand what is written here you will need to have read my previous posts on understanding earth and testing earth)

Plasters and mortars are by far the process that I get asked about the most, and for good reason as plasters are what protect the building from the elements and give them their beautiful finish. Understanding how the material is going to behave right the way through the process, plasters and mortars should be planned for from the beginning. Plasters that are not planned are plasters that fail and if they do the building not only looks unsightly but loses a valuable layer of protection.

As discussed in the earlier articles on understanding earth and earth testing, it is important to establish the most appropriate earth mix at the beginning of the building process. This mix quite literally informs the whole building process from the ground up to the last 3mm of plastering. The initial testing phase establishes a basic cob mix that has both sufficient compressive and tensile strength and has acceptably low cracking. It is important to have an idea of how you will approach each phase and ensure that the different materials ‘talk to one another’ to prevent excessive cracking and delamination, which are the most common failures associated with natural building. Essentially the same original mix is manipulated to be appropriate for different areas, depending on the purpose. Areas that will require the original mix to be manipulated are, amongst others, the foundations and plasters.

It is important to remember that there are as many mixes as there are building sites and what follows is just a taste of what is possible. Over the years one comes to settle on a strategy that works and begins to perfect it to prevent failure. What follows works, but is by no means the only way and is one amongst many.

Let us imagine that the mix you worked out after the testing phase was two parts clay and three parts sand, i.e. 40% clay earth and 60% rough sand, and straw. Just an aside, this formula would indicate that there is a percentage of silt present in the clay earth (often the case), otherwise the clay percentage would usually be lower.

Let’s start with a mortar mix for the foundations. Firstly you will leave straw out of the mortar mix for the foundation, as it would degrade with any moisture. Obviously the foundation should be able to resist water, so using un-stabilized mud-bricks or cob is not possible; ideally you have rock available.

Lime is often seen as the answer to stabilise mortar mixes, as it hardens over time especially when exposed to moisture. However, lime is not friendly to the environment due to the high embodied energy i.e. the energy used to create the product. Over time lime does re-absorb the gasses given off by it during its production, the energy required in this phase is considerable and may well come from a polluting source such as coal. Furthermore, lime is quarried or produced by crushing coral. Lime also makes the material more brittle and prone to cracking, even though the material gets a lot harder, compressive strength is not everything. Often, lime is considered to be better than cement, not because it is less damaging to the environment, but rather because it is naturally occurring and an ingredient of cement. So the strategy should be to minimize its use.

Earth mixes are more plastic and able to resist a certain amount of movement so care needs to be taken just where you apply the lime. However the use of lime is beneficial in foundations where the pros of lime, its hardness and resistance to moisture, are required. With the earths in our example, a mortar mix that will work with the rock foundation is 30% clay, 50% sand and 20% lime. This keeps the material as close as possible to the original mix while getting the benefits of the lime right where you need it. If you pay attention to how the rock work is done you will minimize the use of the mortar and thus minimize the use of lime.

As your house is exposed to variances in temperature and humidity, you want to prevent the materials in the walls from moving at different rates as it causes delamination and cracking, which is in my opinion, the number one reason for a natural building failing. To help prevent this you need a good mortar mix. This is an area that your mix does not need to be manipulated. Between your mud bricks it is ideal if you stick to the original mix that came directly out of the testing phase, including straw.

While some imperfections are fine in the foundations and mortar mixes, any imperfection in your plaster mix will have dire consequences for you final finish. This is mainly because there is generally no amount of acceptable cracking in the final plaster as this leaves the building vulnerable to water erosion. In a nutshell, plaster provides the final finish look and provides protection from the elements.

I have adopted a three phase approach to plastering that is well accepted and works. The first is the scratch coat, the second the form coat and lastly the final plaster coat. The scratch coat is your original cob mix applied to the mud bricks to give purchase to the subsequent layers. It includes straw and is left rough often with lots of fingertip marks.

Scratch coat on this straw bale building near Groot Marico includes more straw and is left rough and textured.

Scratch coat on this straw bale building near Groot Marico includes more straw and is left rough and textured.

The form coat is just what it says and creates the final shape of the building. At this stage it is best to leave out the straw as you don’t want anything protruding through your final plaster coat. The form coat is hand smoothed in such a way that the final plaster coat can go on evenly with a plastering trowel or steel float. Fine cracking is still acceptable in this phase.

On this mud brick building in Scarborough near Cape Point, you can see the scratch coat on the left, while on the right the form coat cob mix, excluding straw, is being hand smoothed.

On this mud brick building in Scarborough near Cape Point, you can see the scratch coat on the left, while on the right the form coat cob mix, excluding straw, is being hand smoothed.

Prior to the final plaster you will need to do a number of tests on top of your form coat. This is done to ensure that there are no fine cracks that will lead to erosion by water. Often cracks create wonderful patterns and you may want to leave the mix to show off its beauty but only on the inside plaster. On the outside no cracking is acceptable after the material has been polished. Usually I do about four tests to select the best mix. Based on our theoretical mix for this article the four tests may look something like this.

  1. First your original mix, 40% clay, 60% sand with 5 % lime =105%
  2. Second reduce the clay a little to reduce potential cracking 35 % clay earth, 65 % sand plus 5% lime.
  3. Reduce the clay some more just in case there is still cracking to 30 % clay earth, 70 % sand plus 5 % lime.
  4. Lastly increase the clay content over the original mix, 45% clay earth, 55% sand plus 5% lime.

    The walls were still going up when we started the Final plaster test patches for this compressed earth brick (CEB) building in Scarborough, Cape Point, SA.

    The walls were still going up when we started the Final plaster test patches for this compressed earth brick (CEB) building in Scarborough, Cape Point, SA.

As these samples are applied so thin they will dry fast so decisions can be made fairly quickly, perhaps after three days or so. You will need to choose the mix that does not crack. If it so happens that none of them do, pick the one closest to your original mix to ensure that the dreaded delamination is ruled out. If you are confident that this will not happen then choosing the mix with the highest clay content will lead to a very fine finish.

Technique is as important as information when it comes to natural building and nowhere is that more important than with the final plaster mix. The final plaster mix needs to go on evenly between 3 and 5 mm thick. The mix changes slightly to include 5 % lime, but only in these last few millimetres. The reason lime is added to this final 3mm – 5mm of the walls is to improve the resistance of the final plaster to water; the percentage is kept low so that the material does not become brittle and prone to cracking, and allows the natural plasticity of earth mixes to overcome small amounts of movement and not delaminate from the wall. There is also a reaction that takes place between the lime and clay that is complete between 5 and 7 %, which greatly increases its durability.

The final plaster mix will need to be finely sieved so that bigger particles do not protrude through the plaster and the result is smooth and even. I prefer the common kitchen flour sieve. Don’t be put off, by how long you think it would take, because you really need so little for the final plaster mix that it goes quite quickly and you can do it directly into a bucket.

Here the final plaster coat is being applied to the exterior of the straw bale building near Groot Marico. It’s between 3mm and 5mm with 5% lime and polished.

Here the final plaster coat is being applied to the exterior of the straw bale building near Groot Marico. It’s between 3mm and 5mm with 5% lime and polished.

Once the final plaster is applied it is polished to provide a very smooth almost fine leathery appearance, further driving the material into the wall and providing durable weather protection. A plastic tool cut from feta or ice-cream tubs work well for this final polishing stage.

Once the plastering is complete, coat the building with three coats of raw linseed oil. Mix the first two 50/50 with mineral turpentine to ensure that the linseed oil penetrates well into the plaster. Allow each layer to dry before you apply the next. Finally a coat of undiluted raw linseed oil will finish it off.

Looking at the whole process as being one thing instead of being separate little bits helps to avoid common problems. Always pay attention to the testing phase, understanding that the same mixes you use for your bricks and mortars will be reflected in your foundations and plasters.

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https://www.naturalbuildingcollective.com