Facts about strawbale

Home builders have experimented with building materials since history began. Strawbale houses built with small square bales originated in Nebraska, soon after the mechanical baler was invented. Nebraska was plains country with very little trees for building so someone with imagination saw a way to use these big bricks for construction. Nebraska style and load-bearing style are interchangeable terms meaning the same thing. Most houses being built are non-load bearing, in fact we have helped people build over seventy houses and not one has been load-bearing.

In Nebraska, in the United States, many strawbale houses over hundred years old are still being used as homes. An American magazine called The last straw had an article about how some of these houses were tracked down and checked for straw quality within the walls – the straw was as good as the day it was put in. Strawbale buildings stand the test of time.

 

Facts about strawbale

  • The walls have an insulation factor of between R8.0 and R10.0, reducing the need for air conditioners or heaters, therefore saving money. Read on how the render acts as thermal mass and helps to mediate temperature, a case study on a strawbale house in the Bega valley has the stats.
  • Strawbale construction has passed Australian bushfire testing.
  • Straw is NOT a food source for termites. Rats and mice CANNOT live in the walls because they would have to get through 60mm of hard render.
  • Most areas of Victoria and Australia have Strawbale houses so council approval is normally as easy as any other building.

 

Environmentally Friendly

Strawbale houses are environmentally friendly on several different levels. Straw is a waste product which normally gets burnt adding to greenhouse gases. Straw is also a renewable product grown in one season.

The insulation properties in the bales means extra insulation does not have to be added to the walls reducing materials in the building process and energy used to make them. The insulation afforded by strawbales also reduces heating and cooling costs but also reduces greenhouse gas emissions from the power generation no longer required. Each Strawbale house quite literally saves tonnes of greenhouse gases from polluting the environment every year.

 

Financially Friendly
Strawbale houses promote financial savings on heating and cooling up to $1200 -$2500 per year. If the money saved in heating and cooling (on average, $1500) was put into the mortgage of the average home loan, roughly three and a half years off the term of the loan could be saved, that’s more than $60,000!

As we are already feeling the affects of global warming with average summer temperatures going up and power prices never seem to go down, it is inevitable that cooling normal houses is going to become even more expensive, therefore strawbale houses is a viable economic option.

 

Strawbale aesthetics

Strawbale houses can look the way you want them to look and lend themselves to nearly all style of house design. The finish of a strawbale house has be seen to be far superior to the average mud brick house and appeals to a much wider market if ever you have to sell. The large window ledges and curved corners appeal to a lot of people. See more examples of strawbale houses…

 

General building process

Slab on ground is now being used more than timber floors with sub floors as it is easier to pass the five star energy rating and easier to build so most architects are going this way. Next a post and beam frame is erected and the roof pitched, the roof is then clad giving a nice protected area to store the bales ready for building.

A load bearing house does not have a frame and is possible but cost about the same and causes complications in the design and construction. Most importantly I think is the limitations on the shape of the house and the amount of openings allowed in any wall section which hampers solar passive design.