An ocean apart, hot on the heels of the Camp Kawartha Environment Centre project is the BaleHaus at the University of Bath. Both projects feature prefabricated straw bale wall panels that were constructed and plastered under controlled conditions in a warehouse. The projects are to be completed by August and September 2009, respectively.
Looking at the prefabricated wall photo gallery for the Camp Kawartha project and the videos below, there are a number of differences. The Environment Centre’s walls are made lying down with a box beam frame of plywood and dimensional lumber, meaning much less wood is used. The BaleHaus project’s ModCell™ wall uses bale pins, solid laminated wood frames, and is baled vertically like a site-baled wall. North American builders have abandoned the practice of using pins except where it may still be prescribed in early and unchanged straw bale building codes.
Camp Kawartha Environment Centre prefabricated straw bale wall panel video
University of Bath prefabricated straw bale wall panel video
BaleHaus at Bath Simultaneous straw bale wall prefabrication projects
It’s great to see who is doing what with prefabrication using straw.
We used to do a very similar system when we first started, creating a plywood box frame into which the straw is placed and have also built panels on their backs but found that more render was being used than required. If we are building using hemcrete we still cast those on their backs but render them vertically. Today we now spray apply the lime render vertically and use solid timber frames for a number of reasons:
The structural loading tests we have done at Bath Univeristy and the regulations that we need to comply with here in the UK has determined this technique to some extent.
The other, was the question that we posed ourselves – how could we bring straw bale and hemp cladding into volume production for housing? The ply box system we found to be labour intensive and we would have struggled to scale it up to meet the demand for the housing we are targeting. The solid timber method uses a CNC fabrication process, where we create a monolithic timber blank and then automate the cutting and drilling as a subtractive process. We also use solid timber for the floors, internal walls and roof of BaleHaus.
This means we can meet our target of building 400 homes a year while still engaging local skills labour and materials through our Flying Factory concept. By automating the frame manufacture we can distribute components as a flat-pack system (a la Ikea) and then assemble the panels locally and still offsite.
The solid timber also allows the panels to be load bearing and can help stabilise a building up to 3 floors before we need to engage internal shear walls. In the UK we need to work to standards that deal with progressive collapse of buildings triggered by a system built tower collapse in the 60s (http://en.wikipedia.org/wiki/Ronan_Point). Local building regulations may account for differences in approach.
I also checked out your blog and was interested to see that staking is not required in north America any more. The wind loading tests we have done show that the stakes play a role in keeping the straw in position within the frame, particularly around the edges of the panel. Without it, we saw the bales slip relative to the frame.
If you check out the ModCell website you can see the other prefabricated projects we have done over the last 9 years.
I look forward to seeing the the finished Camp Kawartha Environment Centre project and it would be great to keep the conversation going as both projects develop.
We have also pitched the idea of prefab straw systems as a mainstream solution in The Good Entrepreneur Competition. If you think building with straw and other photosynthetic materials is a good idea why not rate our Grow Your Own pitch at:
http://www.goodentrepreneur.com/The-Competition/Entries-Pool/Photosynthetic-Architecture-or-Grow-your-Own
Dear Sirs:
I have been looking for any information about building with strawbales. I live in Chile in the most damaged area due to the earthquake. I really want to try this option and would be so grateful if you could give me as much information as possible. I have been reading about you and watching the videos. I live in my farm and my house almost collapsed with the earthquake. It is an old big beautiful house, built almost 100 years ago by my father and his parents. It is built with traditional bales in those days, well built as it has resisted 1960 earthquake and with the present one it did not quite collapse but has serious damage in some parts.
Would you please give me some advice?
Thank you in advance
Yours friendly
Verónica Fernández
Hi Veronica please visit strawbalehomes.com we have been designing & building straw bale homes since 1993. You can check out the FAQ, book bibliography and are welcome to ask questions.
Cheers
Bruce Glenn
Hello. I am master student of mechanics in my thesis, Design and the device through the wall panels are made of agricultural waste can be information you want to build devices please please help me in making devices. Thank u