I'm rounding the homestretch on the 16' x 24' cabin plans. The end is in sight. After months of designing and redesigning, I've finalized the structural plan enough to start working on a materials list, finding suppliers and costing things out. And then going back and tweaking my model with necessary changes to stay somewhere close to our budget.
For instance, we'll have to forego the metal roof this time and go with shingles. It's not ideal, and won't make for good rain catchment... but we can afford it and it doesn't rain here enough anyway. The nice enclosed porches that could be turned into arctic entries every winter with a few foam panels? Those had to be post-poned as well. All the other niceties, like big windows in the living room and tongue-n-groove flooring, don't really result in enough cost-savings to eliminate.
So I feel that I've stripped down the design and construction of the cabin to barest of bones, with the absolute least amount of material waste, while still maintaining a safe, livable, and warm abode. Designing the whole thing on a 4x8 grid to match common building materials helped keep costs down ALOT, even if it made building the stairs a total PITA. It's been a challenge, but worth every minute.
What we've ended up with is a box made of 6x12 (everything yellow is 12") sill beams and girders, that rests on our piers on top of adjustable screw jacks. The 6x6 posts go on the sill box frame and support an identical header box frame creating the loft and supporting the gambrel roof. This is the main load bearing structure and more than adequate to handle the loads - including snow, wind and seismic (whew! doing all THAT math sucked!)
The concrete pad and pier foundation is completely on the surface because of the permafrost, and the crawlspace is 36" above grade to keep from thawing it out. Between the concrete piers and the sill beams is an adjustable heavy-duty (15-ton bearing/2-ton lifting) screw jack so that we can level the house in the spring and fall if there is frost heave. That's one of the reasons we had to build such a beefy load bearing frame for the main "cube" -- can't have the house joints bending and flexing too much while we're twiddling with the jacks.
Between the wall posts, we'll be installing a double wall, with a gap between, made of 2x4 studs that are staggered 24" on center (no thermal bridges!) and then the entire 8" cavity filled with blown cellulose (for about R-30). The 12" floor and rafter cavities will also be completely filled with cellulose (for about R-45).
The south end of the first floor is the living room and kitchen area, with the woodstove centrally located. There are 3 big windows on the south face (2 down, 1 up) to let in light and some tiny bit of solar gain in the winter (but mostly they will have thick insulating curtains on them in the winter to keep in the heat).
The north end of the first floor contains an 8x8 pantry for all our non-freeze-safe food storage needs (since we stock up for the entire winter), and the staircase (I don't trust ship ladders because I'm a spaz) with our composting toilet and a sink (yes, a real sink!!!) underneath. There is a small ventilation/light window in the bathroom under the stairs, and a fixed glass picture window upstairs (we couldn't ignore the view of the mountains even if windows on the north face are a bad idea).
The loft will have the bedroom, our water storage tank, the battery bank & inverter and (finally!) a small office/desk area. The super-steep (12/3 & 7/12 pitches), braced gambrel truss roof allows us to have almost full usable floor space in the loft, even if it requires a ladder permanently affixed to the roof so we can get up to sweep the chimney.
Both porches on the east and west side are 4' and we will be screening them in even if we don't fully enclose them yet. The porches will be used to store firewood, the generator, fuel and to set up our little propane burner so I can do my canning without totally heating up the house.
So that's the plan anyway. Next time we're in Fairbanks, we'll place our orders at the lumber yard and builders supply warehouse and should (hopefully) have the rest of the driveway and homesite cleared before they deliver everything to the side of the highway. No one will come down our trail in a big truck, not even for the pricey delivery fees :( Oh well, at least I won't have to drive back and forth to Fairbanks a dozen times ferrying it all 3/4 tons at a time!
Now let's see if we can build it level, square and plumb; and get it all dried in and insulated before winter comes again. :) It'll be nice to have solid walls again.