New phase in life (building our own cabin)

[Cricket]

So wife and I just got on island and are staying with friends. We have spent plenty of time here in the past and bought a lot years ago, had an area flattened out in the a'a' and some finer agregate brought in for a cabin and I even put in a cesspool. We are planning on starting work very soon building an unpermitted and offgrid cabin, but boy do I have some questions I'd like to crowdsource here.

I'm going to be doing this myself, with the help from the little lady and my friend I am staying with said he'd offer up some assistance should it be needed.
I'm a pretty handy guy who can figure things out, though I have never build a "home" before.
We want this to be "our thing". We've always dreamed of building our own small place to live and doing it ourselves. Downsizing has been a long time coming.

It's going to be a simple place, 16'x24' with a skillion roof.
I have built a couple of sheds in the past like this, so a cabin should not be much different, just beef up a few things, hurricane strapping on the rafters, 16"OC studs, etc.
I guess my concerns are all.... Hawai'i specific.

So to start, I'll put my main concern on the table here and stop rambling. I'm sure I'll have more questions as I get closer to build time.
I plan on making some molds and pouring the footings directly on the crushed and compacted lava. Others in my area just have tofu blocks tossed on the ground, so I guess I am going a step above that. Any pointers on mold size/thickness? Is it really necessary to pin the molds?
Is there a "problem" with pouring the molds on the crushed a'a like I plan?
Of course, back on the mainland things are always different, would have to dig several feet due to the frost heave. I'm just trying to figure out the way it is done here.

[randomq]

I've seen permitted home plans where the foundation blocks are buried in the gravel, and plenty of older homes where they just sit on top. I dug out the ripped lava and filled the holes with rebar and concrete, in the hopes a hurricane would not carry my home to Oz. We'll see.

16x24 is pretty big, I'm not sure I'd be brave enough to do that on my first structure. No matter what you build you will make tons of mistakes and compromises, especially if you are in a hurry to get out of the rain!

If I were starting over I'd do a 12x16, and then add porch and lanai front and back. Outdoor living space is the best! You'll want to sleep out there in the summer.

[Rob Tucker]

In considering your foundation you are going to want to think in terms of earthquakes and hurricanes. Some old houses were just sitting on a brick with no attachment. An earthquake can cause your building to dance around depending on the event. So being attached to the blocks or concrete is of value.

Hurricanes are another matter. They are longer duration events and you should take into account your "exposure". One house on the shore with no shelter will be teeth in the wind. Another location might be sheltered from the wind by trees, hills, etc. Consider your exposure to the wind.

[Cricket]

I guess I should put out the "pertinent" information.
Our lot is in Ocean View (below the highway) at about 1300 feet elevation.
There is a high mound of lava on the mauka side of where we are planning on building, about 15 feet high, that wraps to the south a little to give us shelter from the high winds that come from that direction. From talking to the people who have lived in the area for years, kona winds are rarely "strong", even during the last TS that hit here (Darby?).

We rented for almost a year in lower Puna years ago before heading back to the mainland. So we are familiar with that area. While beautiful and green, the rain really drove me nuts. We rented for 6 months in the lower Ocean View area previously and really liked it there so we purchased a lot for pretty cheap (even considering the area), came over and started working the area (grading, cesspool, etc) then went back to the mainland and let the place sit for years. Now we are here for good, no ties left to the mainland.

My friend here said that Punaweb was pretty much the best place for information from local people on building. Better than trying to use Facebook and stuff. I spent the last week on this site and think I have read through every thread regarding building, offgrid, etc. Then I signed up to start talking.

Rob, I know you know your stuff. If funding was not EXTREMELY tight I'd consider your products. But we have nothing much as far as savings. At least I own my land, so that's a big plus.

Randomq, thanks for replying. And you are right, I do plan on sleeping outside a bit (in the summer), it was 65DEGF here this morning when I checked. So that's out of the question right now.

I have confidence in building something 16x24, as I've done it twice. Once in the U.P. of Michigan for a garage, and another in South Carolina that was used as a workshop. Both are still standing. But that is there, and this is here, and I am not jaded enough to think that things are the same. It really is doing the footings that I have so much doubt about as obviously I have never done anything on lava before... but I'm learning. If I had the cash, I'd outsource that out to someone who knows what they are doing.

[Rob Tucker]

I am not concerned if you build with my products but I will let you know I have a new product line which you might just take a look at.

Just for information sake.

www.modularfarmbuildings.com

Mahalo!