greenspree.ca at The Sietch

Some common questions (usually relayed to me through my Mom!) we’ve been getting are:

Q) How does the cost compare to conventional construction?

A) This is a difficult question to answer. We are doing a 1144 sf home for about $92,500. This is extremely economical at about $81/sf. HOWEVER, we are building it ourselves, have miminized costs through simplified building and finish techniques that could be applied to any type of building and are using some free and reclaimed materials.

I don’t believe the use of straw is saving us anything in construction costs, especially as we are still using wood stud walls and merely using strawbale as an infill technique. Other methods of construction may cost less up front but would require more labour and are more likely to cause your bank/insurance provider/whatever more concern.

Q) Are you worried about fire/bugs/rats/mold/big bad wolf.

A) The short answer is no/no/no/a little/if I hear that “clever” and “origianl” joke one more time!

Strawbale walls have been studied under controlled circumstances and shown to perform better in a fire than conventional construction. The compressed fibres and seamless stucco and plaster skins limit the amount of air available to maintain combustion compared to conventional framing.

Bugs and rats actually have a tougher time getting into a strawbale wall then a conventional wall, especially wood shingle walls! Anyone in an old farmhouse can attest to the ease with which critters get into a wall shingles with old cedar shakes.

Mold and rot is a concern. Straw is an organic compound and if moisture levels reach above a certain level mold and mildew (rot) can occur. That is why conscientous building techniques and details must be used. The methods we are using are tried, tested and proven and we are on top of a well draining hill with 8″ of drainage gravel under our slab.

If you make a big bad wolf joke i will probably give you a dirty look and ignore you for a while.

Q) Why are you building with straw?

A) Three reasons.

1) a straw bale wall is a cheap way to superinsulate your house. R-Value’s (the measurement of how quickly thermal energy travels through your wall, the higher the number the slower the transmission) of about 40 are achieved with proper installation and detailing of strawbale walls, compared to 17 for a 2×6 wall with fibregalss insulation. To get the equivalent using conventional building materials, the wall would need to be furred inside and out and 2 – 2″ layers of rigid insulation applied to each side of the wall. Not evry cost effective of resource efficient.

2) Straw is a rapidly renewable resource and locally grown, harvested and sold. Unlike fibreglass insulation which is man made, energy intensive and shipped long distances.

3) Using straw bales, even in an infill only technique like we are using, replaces a large amount of wood and gypsum board normally used in house building.

Our studs in the exterior walls will be spaced 19.2″ apart instead of the typical 16″ (Code only requires 24″) reducing the number of studs overall.

Our strawbales acts as both an exterior and interior sheathing for the application of finishes and cladding. Where we are stuccoing and plastering outside and inside respectively on our bales, in normal construction we would need to apply a substrate layer (rigid styrofoam, playwood, gypsum board etc…) on each side of our wall.

Q) Why aren’t you building your house using loadbearing strawbale techniques?

A) This is one we get from people who are already familiar with alternative building techniques. The answer is another 3 parter.

1) Infill allows us to build our building, get a roof and 2nd floor up before the strawbales arrive. Straw is cut in September for most crops, meaning loadbearing would force us to wait till most of the good weather is gone to do a big chunk of the outside work. We also will have a roof and dry area to place the bales when they are delivered, keeping their exposure to moisture to an absolute minimum.

2) We are novices with only theorhetical knowledge on straw bale building. Starting with conventional framing techniques allows us a comfort level of doing construction we KNOW how to do and KNOW will be structurally sound, while still reducing the amount of wood we are using on the project.

3) PEI is not exactly the epicenter of the alternative building world, or even of Canada. The underlying framing technique is familiar to local bankers, insurance companies, mortgage inspectors, etc, while the infill technique is easily explainable and not too “out there”. That being said, those we have dealt with seemed very open and excited to be a part of building a strawbale building so I think a loadbearing structure wouldn’t be TOO hard to get off the ground either.

Well that about sums it up, hope to see you out for the raising, remember, this is not just for people who want hands on experience, there will be plenty of people there just to watch and learn. Education and exposing people to new ideas is another big reason we are doing this project the way we are!