Since you offered...
Wow, tons 'o photos.
Just a couple
Count me among the people who are surprised at the presence of a
cesspool...
Cesspools are still allowed in a lot of areas of the big island. The ground is rock and porous. They star jack hammering the hole with the back hoe and go down until they get into fractured rock. It gets inspected and when passed the back hoe man comes back, lays 4x4's over the hole with a layer of old roofing tin, lay some rebar in and cover with cement. That's it
There are more areas where septic systems are being required. Cesspools will eventually be phased out. This cost me 2500 bucks a septic system would have almost 7 grand
So is the catchment tank + gutters the only source of water for your house? Considering how much rain you had during construction, maybe I shouldn't be surprised.
Yes, that is our drinking, flushing, and irregation water. And in emergencies like a house fire the pumper will (if needed) put a sucksion line in the tank and continue fighting the fire. If you don' have at least 10,000 galons your fire insurance is higher As you seen in the photos we have a pump, filters, and a UV steralizer light (that silver tube in the photos) I have no qualms about drinking the water. We've never had any problems runnng out of water but there is only the two of us. Bigger families do at times have to buy water when it gets dry for a while. I can't remember how much it is but a truck with 4000 galons is like 250 or 300 bucks.
The only sheathing I saw was the vertical tin panels. That's it? So your walls consist of drywall on the inside, insulation, and then a thin bit of tin on the outside?
It just seems flimsy to me. Or is that "thin tin" a lot stronger than it looks?
There is a t-111 type siding it is 1/2"x4'x10', tyvic, and sheetrock. The only insulation I put in is the the bathroom walls. Don't have to listen to the "tinkle" that way The roof is steel. If maintained will last years and years. I do wish I had put some of that silver colored blanket insulation in the ceiling. It can get warm at times. I did put in an automatic fan in one gable end. Kicks on at a preset temp and goes off when the sun goes away. The construction is stronger than it looks. After the trusses are up there is metal straping layed out in a "X" patern. On the size of ours there was a double "X" side by side. The perlins are layed out next on 24" centers, and on top of that is the tin. There is talk they may call for 1/2 ply sheeting under the tin in the future but I wouldn't want is as you loose so much attic ventalation.
You seemed to either put gravel or cinder over a large amount of property. Is that common? No topsoil + grass or other growing stuff? (Hey, San Diego is the closest I've ever been to Hawai'i, so I know very little about things down there.)
The only tops soil we have comes basicly from the "older" end of the island. They have a red soil that is sticky and gooy like clay when it gets wet and is 30' deep in some areas. Very poor drainage. There is a product called cindar soil. It is a dark cindar that has a lot of fines in it and mixed with mulch. Very expensive The red cinder will break down faster than the black and both are good growing medium. If I wanted I could plant grass on it or there is an alternative that is like a real couse grass, grows slow, and quite hardy. Don't know what it's called but you start it with plugs and then who mowes it???
Was there any consideration to solar electric or solar hot-water-heater panels? I would think that the further south you live, the more those make fiscal sense.
I know quite a few people that have installed various sizes of solar power system. Electricity is about .33 a kw It's the up front cost that is prohibitive. There is a lot of maintenance involved with it too. Very easy to "cook" your batteries like one man I know. Cost him another 4000 bucks for another bank of 6v cells. Solar hot water would have been another option but I've got a tankless gas fired Takagi jr on demand system. Very economical and again it was 5000 bucks for a solar system There are a lot of fed and state tax breaks but you pay up front and have to have it installed by an otherized person. There again, didn't have enough capitol for that. I have 2, 100# propane tanks (23 gal.) and one will last about 4-5 months for the two of us. That is for hot water, cooking, and cloths dryer. It cost 95 bucks to fill one tank. Two years ago it only cost 75 bucks to fill.
I was surprised to see that you put drywall on the ceiling of your Lanai. With all that rain that you noted during construction, aren't you worried about it getting wet and ruined? Or is it a special water-resistant kind?
Yep, that regular dry wall! When it rains here it is wierd. Most of the time you'll get a small gust of cool wind and then in a little bit the sky opens up and the rain comes straight down hard for a while then will stop in the snap of your finger! I've seen just buckets coming down across the yard at my neighbors house and dry at ours and that is about 60' away! So knowing how it rains come down we have at least 3' eavs and that keeps the sheetrock dry enough to "hang" in there You do have to keep an eye on it for any mold that might start. I used paint with a fugiside in it and after 2+ years it's still looking good, other than the Geko poo.
congrat's on a great looking house!
...art
entire project is superb. 
