Why build with straw bale?
Straw has fantastic thermal and acoustic insulation properties and it is a waste /by-product from agriculture.
Won’t the straw rot?
Rendered with lime sand render any moisture trapped inside the wall ‘breathes’ out, keeping the timber and straw dry. The render also adds to the thermal mass of the building.
What about termites and bugs?
Straw (different to hay) is a by-product of agriculture – so termites, bugs or vermin are not interested in eating it at all. It’s so densely packed, so only very tiny insects can make their homes in the walls. Fewer than those that live in a double brick wall cavity.
What about fire?
Straw walls with render to both sides like ours have been tested by CSIRO to withstand most bushfires, and tests done in US and Canada prove 2-hr fire ratings for rendered straw bale walls.
Is it really strong enough?
In our house the straw is infill – the structure inside is made of engineered timber columns and beams and steel bracings.
But load-bearing straw bale houses are possible and there are many examples in WA and indeed all over the world. The oldest straw bale house still-standing was built in Nebraska in 1903.
When did you finish the house and how long did it take to build?
The house was completed in 2011 and took a bit longer than 2 years to complete (while we were still working full time).
How much did it cost?
It cost us between $300,000 to $350,000 to build the house – that included all the fixtures, furniture, landscaping and car parks. But that doesn’t account for the time we spent ourselves as the architects & owner-builders.
Why is your house such an odd shape?
We think we hit the jackpot with this triangular block. It had difficult construction access and was therefore affordable, but it had a fantastic north orientation, views in all directions and was so close to the bus stop and shops.
The angles of the house align with the shape of the triangulated block. The layout also maximises views to the city and ocean, takes advantage of solar heating and provides shading as well as access to natural ventilation. As a side-effect the angle and direction of roof ended up in the almost perfect orientation for the solar panels.
As a bonus we now get the most amazing sun light show with reflections through the entire house from sun rise to sunset.
Was it hard to get approvals?
The City of Stirling was very positive and speedy in giving us planning approval and building permits, considering this was the first straw bale building for the council. We provided them with a lot of information, including straw bale building codes from US, testing/ rating results, and many details of our construction method to assist the approvals process.
Do you really not pay any bills?
We don’t! Over the year, the credit from our solar rebate evens out the gas bill (a small gas bottle every 2 months) and the water bill. It also pays for those dark winter weeks when we sometimes get a small electricity bill mainly due to the need to boost the solar hot water.
Do you do anything special with the water?
Yes, the rainwater is used for drinking, cooking and another tank is connected for toilet flushing. The water from the laundry and shower waters the gardens.
Where is your TV?
We don’t have one. We do have a TV set top box connected to the projector upstairs which we sometimes use to watch movies, the world cup (and Eurovision)!
There are only two bedrooms upstairs. What will you do when the kids want their own rooms?
All the internal walls are flexible. The upper-most floor could easily be divided into a kid’s bedroom. Also, the wall between the bedrooms is only connected to the furniture and can be easily dismantled, so the bedrooms can become bigger or smaller as our needs change.
Also, as young adults, the kids may want to move to the downstairs unit!
Would you do it all again?
Absolutely. It was a lot of work (a LOT!) but well worth it in the end. We get to live in a unique house that meets our needs perfectly and changes and evolves with us!
It has proven to us that a sustainable house does not mean you should lower your expectations, restrict yourself or give up little luxuries on the contrary it actually enhances your comfort and lifestyle.
