Best Natural Building for BC? Gulf islands zone 9a

Hi there, we are about to start a sustainable project in the Gulf islands of British Columbia and I am wondering what is the best natural building approach for here. It does not seem to freeze much here but the average temperatures for December/Jan are around 3 degrees c. We wanted to build with earthbags as we have some experience with them, but now I am concerned if there will be enough insulation. I know of someone who built with Cob not so far from here, at the south end of Vancouver island and he recommends insulating the north, west & east walls. The thing is straw bales are hard to get here and expensive, same deal with Pumice, so I was thinking of woodchip clay or buying cellulose, both of which I would need to create forms for around the earthbags.
I would appreciate any ideas and or feedback from people living in this area.

Hi Mark,

Here's my take on it. I've never built a natural built house, but I have taken a 7 week intro to natural building course (we covered many different materials and did get plenty of hands on experience building a community garden shed). I'm also an Island boy, born and raised.

Locally sourced possibilities include log cabin style, Cordwood style, and Lightclay style.

I'm partial to lightclay for a few reasons. I like the fact that it's non-structural, just infill. I think this would be easier to get permit approval for, since the framing could be more standard than a monolithic style build. I also like the fact that any damage to the lightclay (moisture?) is repairable without worrying about structural integrity. Lightclay can be constructed with wood fibres, making it viable for the coast (no straw, lots of wood). It is also possible to adjust the clay/fibre ratio to choose insulation or thermal mass.

I've seen ideas for framing a structure with lightclay in mind, using alternating dimensional lumber to prevent thermal bridging. Imagine a 2x12 sill plate with 2x6 studs, first stud to the interior side of the sill plate, next stud to the exterior sided, and so on... (I can try and create an image for you if this is confusing).

One source for the beautiful potential of lightclay is EcoNest.

Hi Kirk

thanks so much for your response and yes I think you are sharing good advice with me!

Actually we volunteered at a wood chip/clay slip project in the Kaslo area this summer, basically it was a wood frame structure with temporary forms in place to allow us to fill with the wood chip/clay slip mix. I was attracted to Earthbags because I don't have much experience with timber framing, but I think it may be the better approach for us because of the insulation we will gain. We will still get to do some cob work inside, like a rocket mass stove and of course we can use earthbags for other projects like a root cellar, sauna etc
Do you know what thickness of woodchip clay we should use? How about insulating the floors and roofs, any thoughts there?