I’ve been corresponding with one of our readers in New Zealand about low cost, alternative cabin building ideas with disaster preparedness in mind. We’ve talked about a whole range of ideas such as using straw bales for energy efficiency. The design presented here is DIY friendly, affordable, suitable for a grid-down situation and can be easily moved if desired.
Just like any location, New Zealand has some challenges that must be addressed when designing a home or cabin. Design challenges here include earthquake resistant construction, adequate insulation, and selecting materials that are available in more remote areas. In this situation it has to be owner-builder friendly, reasonably affordable, and portable in case the owner ever wants to move it.
Here’s a brief summary of the ideas we’ve hashed out so far:
– Pour a concrete or soil cement slab on top of rigid foam insulation and with insulation around the edges.
– Make DIY double arch trusses using a pipe bender and chain link fence top rails. If you’re not a welder, you can flatten and drill holes in the ends of the web members and bolt to the arches. The arches are bolted to short pieces of slightly smaller or larger pipe that’s buried in the slab. These homemade trusses provide reasonable resistance to quakes for small cabins. Square or rectangular tubing are options that are easier to screw to.
– Attach steel rails and durable metal roofing on top of the trusses with self tapping screws.
– Install outlets and any other desired mechanical components such as fans, cabling, etc.
– Frame in a window wall on the end that faces the sun (north facing in NZ). Make insulated curtains to seal off this wall at night to conserve energy.
– Frame in the other end wall of this arched cabin to join a pre-built unit that contains all of the mechanical systems as explained in this previous blog post.
– 8” of sheeps wool insulation is approximately equal to straw bales but without the drawbacks of losing space, etc.
– Add wood T&G or lap siding on the interior.
– Design the cabin with counters, closet, sofa/bed and desk along the outside walls so you have more headroom. Study tiny house videos for space saving ideas. Use throw rugs down the center area so the floor is more comfortable.
– The cabin can be hoisted onto a trailer after unbolting the trusses where they connect to the slab. The mechanical unit can also be removed and transported elsewhere.
– The owner said it would not be difficult to get this design engineered and approved. (No chance of building without a permit in case you’re wondering.) The owner also would like to use 12V wiring because it doesn’t require the services of a licensed electrician.