A house of straw?

An avid Farmer’s Weekly reader has the opportunity to build a straw bale, self-sufficient, off-the-grid home in the Magaliesburg area. Jonno helps her out.

straw-house

Hi Jonno,
We have the opportunity to build a straw bale, self-sufficient, off-the-grid home in the Magaliesburg area, and having been a keen reader of Hillbilly Homes in the Farmer’s Weekly for the last couple of years, my logical choice was to contact you for help with the basics.

Attached you will find a floor layout. We would like the house to be as compact as possible, without feeling boxed in. All drainage should be on one side as we will be doing grey and black water recycling. Construction should preferably be post and beam with straw bale filling.

We’d like to have aluminum windows and sliding doors and all north-facing rooms. We want to keep it all as plain and simple and as cost-effective as possible.

Not sure of the roof design, possibly a hip style with enough overhang to protect the walls.
Regards, Nikki

straw-house

Hi Nikki,
I certainly appreciate your concerns in wanting to keep the building costs as low as possible, and your suggestions of building the outer walls from straw bales. This is an aspect that I’m still trying to get my head around.

I have several quantity survey estimates which were prepared for regular brick-built houses. The estimated cost of the walling material from floor to ceiling is at roughly 10% of the total house cost. Of this 10%, a quarter is for labour.

So at 7,5%, which includes the mortar mix, why would one want to use an alternative material as a substitute? Any of these alternatives will require an added support structure of wooden poles or steel framing to hold the roof up and for wind-loading. Besides, which the straw bales will need to be plaster encapsulated and water proofed to keep the rats from sharing your home.

Besides, which the straw bales will need to be plaster encapsulated and water proofed to keep the rats from sharing your home.

You said that you wanted aluminum doors and windows for your new house. I would imagine that you’d also incorporate all the usual mod-cons, finishes and fixtures too. By acquiring the straw bales for free, you might at the end of the day, save about 2% or 3% on total house costs.

By acquiring the straw bales for free, you might at the end of the day, save about 2% or 3% on total house costs.

I have some very innovative construction ideas using materials that are locally available. These need specific technical applications, which will be included in my working drawings. Added to alternative building methods and materials are the approvals by Local Council, the NHBRC and NB Regulations codes of practice.

Shown in the sketch is the layout you e-mailed me, where I’ve shown the outer walls of straw bales, inner walls of cladded wood framing and also the support poles that will be required.

I hope all this will help you decide.
Regards, Jonno