A sustainable journey building from straw bales

straw bale building

Antbear Lodge (www.antbear.co.za) is all about disconnecting from our stressful lives and reconnecting with the natural beauty of the area. This is a comfortable Eco experience in beautiful organic structures created from straw bales, natural rock, rammed earth, cob and sun-dried bricks.

We started our slow process of alternative building in 1999. As you can imagine the process of architects, planning permission and the like takes a considerable amount of time although we have been lucky living in a rural area where regulation is little and enforcement even less.

The most successful of our eco structures, by far, has been the straw bale construction. Besides that this concept is a great selling point for promoting the sustainable ethos of our lodge it does come with a lot of tangible benefits. From our perspective the biggest advantage was the massive cost savings together with the fact that it’s an easy construction method suitable to be put up with unskilled labour of all genders. For us creating employment opportunities especially amongst women for our local community has always been front of mind and we also like to pass on knowledge and skills development. However, I have yet to see a straw bale construction go up in the community although much of our alternative practices are being adopted, straw bale construction seems to have been a bridge too far.

The resource that we have used make up the bales is veld grass that has been mowed and made into square bales and is off our own land. Just about anything that can be baled can be used. Straw bales are an annually renewable agricultural waste product that is often wasted or burnt by farmers. The total cost to make the straw bales was essentially 2 days of tractor and baler hire. Its important to look at what resources you have access to locally to avoid transport costs and environmental impacts. The straw bale concept has been around for more than 100 years and has been used in many countries around the world so it is a proven concept. The next biggest benefit is the massive insulation factor achieved keeping the building cool in summer and warm in winter.

We have encountered a few disadvantages along the path of our straw bale journey. There were some extra costs needed in that the roof structure increased by about 20% due to the thickness of the walls. It has also been a mission to get insurance cover too because as soon as you mention straw houses the story of the 3 little pigs comes to mind. I can imagine that planning permission where needed might also be an issue although we managed to sidestep this issue due to our rural locality. A straw bale wall does not allow the attachment of a shelf to the wall. A way round this would be to make add wooden supports to the bale walls where you might need to attach something using a wall screw. Another method we found was to make a large wooden wedge, drill a hole through the plaster big enough to hammer the wedge in and then replaster the hole. This does turn the simple putting up of a shelf, into a mission.

From a costs perspective I first need to state that we do the work ourselves together with labour from our local community and that we are very much into the upcycling concept. We have built at less than 15% of what the building would have cost had we done this conventionally. Normal costs applied in the main only for glass, concreate and treated poles for the roof supports and the double line of concrete blocks to get above ground level.

It starts with foundations as normal and a first layer of concrete blocks to get above ground level such that the bales do not get exposed to damp. The method we used to make the walls was a pole framework that holds up the roof with the bales basically filling in the walls, with door frames and window frames set at the same time. Our roofing material is made from thatch grass that has also been cut on the farm. This thatch grass cutting process is labour intensive so while the material costs are zero the cutting costs are substantial especially when liveable wages are paid for the labour. Supporting local jobs is a huge factor for us.

A great hack that we found was that once the bales are in place they can be trimmed using a weed trimmer which creates a lovely organic shaping of the walls allowing features like rounded windows to fit perfectly. The walls are then plastered with mud that has a clay content and sticks to the grass and then finally plastered with a normal cement plaster. This has worked well and the first of our buildings has been around for 20 years now. A point worth considering is that once its built its not that easy to drill a hole through the wall. It kind of just self repairs the hole which means meaning it is a really good idea to put in pvc access piping into the walls wherever you will need to have power, gas and water services supplied while you are laying down the straw baes. We did discover that a copper pipe with a wooden cone attached to the front of it was a tool that can be forced through the wall to make an access hole but this works only for smaller diameter pipes and not the and not the larger waste water pipes.

We have used broken tiles for the bathrooms, home made acid tints for the concrete floor finishes and a lot of upcycled wood and alien wood species. One of the features that we included was a truth window. A glass frame that allows our guests a glimpse of what’s inside the wall. Its has become almost like an interactive picture and always seems to be a conversation starter.

Over the years we have made changes to the building like changing door entrances. This was easy and it was interesting to see that there had been zero degrading of the straw bales when we opened up the wall. On another occasion a leaking pipe caused us to need to open the wall and fix the leak. The bales had started to compost. All we had to do was take out the damaged grass, replace it with new bales after fixing the leak and replaster the wall. A job I was dreading turned out to be a simple fix.

20 years in to our sustainable self-sufficient journey I can safely say that straw bale building has been one the best alternative ideas that we have followed. If you would like to consider building using straw bales you are welcome to come and visit me and I will show you around with pleasure. The most important things I can show you is what not to do.

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