This came in the form of a prefab log cabin - that is to say, the lumber is all cut to shape and size, and you're "just" banging it together. "You" in this case being my wife and I.
Total for the structure was just under €20k - includes windows, doors, insulated walls, floor, ceiling.
Total for water is less than €1000 - IBCs for storage, a km of water line, carbon and sediment filters, UV-C reaction chamber, reverse osmosis.
Total for waste is about €200. IBC. Worms. Cheap plumbing supplies.
Total for power is about €15,000 - most of that cost is in a huge bank of OPzS batteries, and then theres victron gear, a dozen solar panels, a dinky wind turbine, and an experimental (failed) waterwheel. This covers both the mill and the cabin, which are about 600m apart.
So, all in all, it's an off-grid house for under €40k. That of course doesn't include labour, which has been about 1000 hours of our time, from digging and pouring column foundations through to transporting everything to site by aerial cableway - so in many cases it'd be much less, as you wouldn't be building on a 45 degree slope with zero access for machinery.
The thing I keep seeing people getting wrong is energy. Literally yesterday I talked someone out of buying used lithium ion cells from EVs, as while they were indeed very cheap, they likely only had a few years of life in them, so the price/kwH stored amortised over the lifetime of the batteries was terrible. Can't go wrong with lead acid OPzS - 20 year lifetime, easy to maintain - two years in and they've lost basically nothing in terms of their potential. For some reason you don't often see them in domestic installs - but they're super common for battery backups at hospitals, battery storage for renewables providers, etc.
In terms of prefab log cabin, any pointers you could share? (Even if portugal specific)
Thanks
Ours is 70mm milled logs, fit together like tongue and groove. Generally really pleased with how it's come together, although I need to finish the roof, which got postponed by weeks of rain.
Only thing I'd say is that they can be tricky to get permission for in Portugal, but it really depends where you are. Where we are, in the north, where the fires aren't so bad, pretty much anything goes - I have a signed note from the local council saying "it's your land, you build what you like".
Only other thing is don't underestimate the labour. I naievly thought we'd have it up within a few weeks of the kit arriving, but it's been more like four months, and we're still not quite done. Oh, and don't build in winter :)
https://www.h2oreca.it/cerca.php?categoria=giardino%2Fcasett...
Are you putting the log house further up hill? :-?
Love the idea of the house btw - inspiring once the kids get older
This winter the worst we had was 3cm in 24h, and the river stayed a good meter below the level of the floor of the mill, so we now have a better understanding of what kind of weather conditions constitute a danger - the rain we had at the end of 2019 was the worst in 70 years or more.
The mill itself is ancient, and built out of enormous boulders, each weighing tens of tonnes, so the structure was entirely unscathed despite being battered to hell by both the force of the water and the debris that came down - everything from trees to trash to trailers. The roof got pretty badly torn up, so we've had a tarp over it for the last year, as we intend to take it off and put a storey on top this year anyway. Overall, while it was a crisis (we waded out in thigh deep water in torrential rain, and had to walk to the nearest village as our car was already gone, cats screaming in their bag... all a bit traumatic tbh), we've turned it into an opportunity - it spurred us into building the cabin, it's shown us what the river can do and what we should therefore plan for with our projects (for instance, I moved our entire battery bank a few meters further uphill), and the damage to the roof has encouraged us to think about building upwards. It's also shown us what we can bounce back from - lost a lot of posessions, and hosing down the house and everything in it was pretty miserable. Oh, and it happened a few days before Christmas!
The cabin is about 30 meters uphill, and about half a kilometer away, on an old agricultural terrace - nightmare doing the groundwork, and getting materials in, but it's so worth it - spring is just beginning here, and I'm sat in the unfinished structure right now, watching birds flit between the treetops at window level, listening to the stream chuckling in its bed - very different to the perennial roar of the weir at the mill.
It's a challenging lifestyle, but I wouldn't trade it for the world.
I hope it's a lovely spring.
I did discover that you can totally immerse a lot of modern electronics in muddy water, and so long as you wash (urgh, heatsinks) and dry them thoroughly, they live on. Hard drives in the NAS lasted just long enough to get the data off them - NAS itself was fine. Getting silt out of microswitches is also a PITA. Thought the tv was trash, but after a few months, the water that had gotten inbetween the layers of the display dried out, and now you’d never know.
Our main losses were things like mattresses and bedding, the car, books, and a whole bunch of time - took days to hose the mud off the walls, inside and out, and we had about 10cm of silt to shovel out - it took until summer to dry out! The damage outside was also extensive - lots of clearing of debris and chainsawing of huge treetrunks balanced improbably all over the place - at least the flood delivered construction material for the tent platform, which became our home last year while we worked on clearing up the mill and groundwork for the cabin, and taming some of the utterly overgrown forest. This year, as the flood was much smaller, it delivered commensurately smaller wood - but all in all, enough firewood to keep us going until the nights are warm, and some awesome driftwood that’s becoming light fittings in the new cabin.
So far, spring is gorgeous - the valley really benefits from the floods, leaves the banks super fertile - it’s a strip of luminous green in a grey and brown surrounding.
It's very interesting that even after all the improvements in battery tech since then, this still appears to be the case. I wonder how much longer it will hold true?
Lead is at the other end of the periodic table. It's heavy and dense. But the batteries last and last and last, and are well-proven. The lead itself is recyclable,a nd is the most-recycled material by mass in the US IIRC (the USGS reports on this). About 40% of lead production is from recycled lead.
I can't wait for some of the more stable, non-toxic chemistries run through redox flow batteries to become more marketable. For a shelter, I don't care how big the system is, and if all I have to replace is a pump (and I'm trying to figure out if I can use magneto-hydrodynamic pumps to even extend the life of that component) and what evaporates away, the lifespan of the battery is far longer than what we are used to. I'm also interested in nickel-iron chemistries getting hammered out.
Many of these “construction kits” can be seen and bought in a city somewhere on the highway between Chiang Mai and Bangkok (probably Phrae as this[0] company is located there as well).
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For comparison consider that I rent a 45m^2 1 bedroom furnished apartment on the 28th floor of a high rise in the heart of Bangkok for roughly $600/month. I could have a 90m^2 two bedroom in the same building for about $1,000/month.