Permaculture and natural building

The rains are coming to an end and building will start again soon!

Permaculture has been an inspiration for our natural building project, 'Permaculture' sounds like such a strange term that it can be off putting. I have read up on the subject and recently did a two day 'introduction to permaculture' course which has helped in my understanding of what it really is.

Permaculture is a way of living which observes and recreates natures patterns, working with nature rather than against it. It is often used in relation to farming but the principles and ethics apply to every situation, it is a framework for positive action. In the design of our home we have tried to think of the permaculture principles, once we are living in our home, we will apply these to our plot. 

Permaculture Ethics: People care, Earth care, Fair share.

The Permaculture principles in relation to the construction of our house:

Observe and interact

Before starting anything on the the plot we spent time camping and walking around to try and get to know her! We had originally wanted to have the house amongst the trees but this would have meant destroying the very thing we wanted to be enjoying, so we decided to build it just on the tree line in an open area which had been cleared as a field a couple of years before. 

 Catch and store energy

We have tried to position and design the house to best use the sun to be warm in winter and cool in summer. The thick earthen walls will provide ‘thermal mass’ they absorb the suns heat, or the winter cold and as the temperature changes they regulate, releasing the warmth or the cold they have stored. 

 Obtain a yield

We will be catching rain water and storing in tanks, for the garden from the thatched roof, a metal roof from the shed and other structures will catch rain water for washing and other household uses. Eventually building underwater cisterns to collect more water. 

Apply self regulation and accept feedback

There will be rain water collection which will be enough for part of the year the rest of the time we will collect borehole water which at present is 1km away, not having water pumped into the house will be a challenge but from experience we use far less when this is the case. Only using what is essential.

Use and value renewable resources and services

We will have solar panels to charge batteries and for lights, we will run a small 12v fridge from this also. These will be our only electrical needs.

Produce no waste

All grey water will be used on fruit trees, and at a later date a filtration system to use it on other crops. We will have a compost toilet, which uses no water, after the composting process is complete the compost will be used on crops.

Design from patterns to details

The round shape of the house and the internal forms are far more organic than angles, this is very soothing to be surrounded by these shapes.

Integrate rather than segregate

The design of the house has been done to also fit into the rural home designs around us matching the round earthen walls and thatched roof. Living in a place surrounded by nature having an earthen house blends into our surroundings. 

Use small slow solutions

We have tried to design the house for our needs and keep it as small as we can and be comfortable, we would like to create outdoor spaces that are comfortable to spend time in as we spend a lot of our time outside.

Creatively use and respond to change

In a place where anything can happen anytime we have to be able to adapt, this includes this project. We will see as it evolves if certain things need to be changed.

Use edges and value the marginal

The site we chose is on the edge of where people live and the wildlife area. We wanted to live in this area for several reasons, there is conflict with wildlife entering into the areas where people live, those on the edge feel the effects far more. We hope to be able to 'turn the problem into the solution' at least try out different ways to change this. 

Use and value diversity

We will be apply and trying methods and materials to the house which will be a living test, using grass straw rather than wheat straw as it is what is locally available. Using smashed glass bottles for the floor base instead of gravel. Seeing how these and other materials react in this environment with the threat of insects... If some things don't work, we will learn from this!

The Rains have come!!!

The rainy season usually starts in October/November and in this region it is desperately needed and awaited by both people and wildlife. This year significant rains only started in mid January. The plot and the bush around are now looking green and lush.

So with these rains we have paused construction until the end of March, we need to allow the cob to dry during construction, I will continue blogging about ideas, design and any developments during this time.

                            Wild coffee bean Bauhinia Petersiana growing on the plot

Design

This is the basic floor plan for the house, it is 10 meters diameter. It took a long time to decide on the size, we spent many sunday afternoons drawing the design in the sand and putting furniture inside to have an idea of space. We wanted something small and cosy, but not too cramped, so it has 2 bedrooms, a kitchen and living/dining area. We will have a compost toilet which we wanted outside but with our 3 year old we decided to have a toilet inside with a basic compost toilet design which will not have the chamber built in but a bucket which is emptied onto a compost pile. The external walls of the house will be 50 cm wide and internal walls 25 cm wide. There will be a mezzanine above the bedrooms, to use the  space which is created by the thatched roof.

We also want to create outdoor living spaces as we spend a lot of time outside having spaces to sit and relax outside are as much a part of the home as indoor space. All the windows will be rounded and arched, some will be glass panes built into the wall, as well as glass bottles into the wall. The nice thing about cob that I'm looking forward too is adding sculptural details, alcoves, shelves, gecko shaped windows etc.

The roof will be gum-poles and thatch all of which are sourced locally, there will need to be a central support for the roof otherwise I like the idea of a reciprocal roof design but not sure how possible this is with thatch when a minimum 45 degree angle is needed, anyone who has any information on this I would be interested to hear!

Termites the original mud builders!!

Termites are amazing little creatures, when I first moved to Zimbabwe I was amazed to see these mounds that appeared all over the horizon, sculptural and intricate in their own right, these are the original mud builders!! In areas where no clay is found people building mud huts in zimbabwe will use the termite mounds by grinding it up and adding water, then making bricks from this, the result is very strong. I chose not to use this method as I would prefer not to destroy termites homes, after all of that hard work! Unfortunately when building your own home termites can become a huge problem, eating through structural wood. I really don't want to use any harmful chemicals for treating the wood, here the only options are pressure treated poles with Cresote or CCA. I would like to treat wood myself with something less harmful such as borax.

I have had some good suggestions, help and advice from joining a permaculture forum http://www.permies.com , which includes a natural building forum, there are lots of interesting ideas and topics raised. I posted a link to my blog to see if anyone could help and a discussion on termites and wood borers has started up, please have a look if you are interested or have any ideas http://www.permies.com/t/11974/green-building/cob-blog-please-have-look

Details, details...

I drew up the design for this door, which will be the front door. A local carpenter who uses wood from the forestry commission, which is the most sustainable source of wood here at the moment. The wood used is Mukwa. He did a great job, I'm really happy with this, a window pane will be fitted in the circular hole. I love arches and I am keen to have mainly arched doors and doorways in the house, this also reduces the need for lintels. The back door will be rectangular with a lintel as I have some old railway sleepers which look beautiful as lintels.

Any wood which is cut and used in the house, we are replacing by planting more trees which I have grown from seed on our land.

Laying the foundations.

For the foundations we have been using stones which were collected close to the land with a scotch cart. The stones vary in size and shape, larger heavier stones were used for the first layer. Over lapping is as important as in brick work, to ensure no continuous cracks form.

The mortar used between the rocks is the same as the cob mix, but with 15 percent lime added. So to mix this we needed to wear boots as lime is very corrosive. The lime hardens the mortar.

There is no bore hole on the land, so I delivered water each day emptying it into an old bath.

Site selected, marked and pegged, get digging!

The site was selected, Misheck pegged out the building according to the design I had drawn up (which I will post soon!) and we were ready to start digging. It's quite a huge job, I wanted to make the foundations 1m deep and 60 cms wide to make sure the weight of the roof could be supported by the walls.

It's great to start seeing the shape and design come to life! The sand that is dug out of the foundations will be used in the cob mix.

Now the foundations have been dug, the earth below is rammed to compact the earth below.

I've included the site of our future home on the 'Location' link below for you to have a look!