Ducks!

This whole project began for us a few years ago, emerging from Kyle's enthusiasm for vegetable gardening which has been infectious. So we've given a fair amount of consideration over time to what vegetables and fruits we'd like to grown when we eventually have the space for them. At our current place we have a small patch (about 4m by 3m) that does well in summer but is fully shaded all winter, and another section made up of as many pots as I can cram into the paved area around the other side of the house. The first year we were here we had some overly-successful experiments resulting in an abundance of tomatoes and zucchini (which I've vowed never to plant again because I never used them).

We've also given considerable thought to animals also. We already have a cat (strictly indoors). Kyle grew up on a pig farm, so this seems like an obvious choice. Pigs necessitates getting a dog, a gun, or (most likely) both as the presence of domestic pigs is likely to draw interest from feral ones which can be dangerous but are somewhat deterred by large dogs. I'd love to keep bees, which is probably a separate post, and rather than keep ornamental birds we'll just plant lots of things they like so as to attract wild ones. So, cats, dogs, pigs, bees and birds.

But then there was the endless discussion about chickens.

I quite like a breakfast omelette, of a morning, and thought free range chickens a great idea. Kyle, who is violently allergic to eggs, didn't see the appeal. Our current neighbours have a rooster which doesn't seem to realise dawn is still hours away at 2am giving us a rather strong impression of the noise associated with chickens, and there was considerable objection to the inevitable scratching in the veggie patch that would occur. A conundrum.

But then, and I'm embarrassed to say it never occurred to us earlier, we happened upon ducks! Seems like all the insect-collecting benefits of chickens without the down sides, and considerably more character to boot. We'd have to manage water very carefully to ensure a consistent supply, but once the property is established with collection tanks this should be straightforward. We haven't tested the theory yet, but it seems sometimes allergies to chicken eggs don't transfer to duck eggs - Kyle is crossing his fingers as he's always liked the smell of eggs cooking. Plus, the cuteness of fluffy little chicks is eclipsed only by a congo line of fuzzy ducklings following mum for the first swim.

Ducks it will be!

Radon Off-gassing

Until very recently I'd never even heard that Radon in homes could be a problem, so when a friend of mine mentioned to me a few weeks ago that it might be a concern in an underground house I began looking into it. What I came across was a bunch of websites from the USA telling me about how it leads to lung cancer and I should be very worried about it, and here's who I can pay loads of money to to fix my home. Ka-ching!

I like to look a little deeper into things like that.

So, I started with what its all about anyway - where does it come from? Apparently, underground. The gist of it seems to be that Radon gas exists in the soil, at varying levels across the world, and slowly leeches up into the atmosphere. It's radioactive decay over time can contribute to lung cancer and other unpleasantness, particularly at high levels, though there doesn't appear to be useful data on 'safe' levels, just 'advisable' levels (US website are careful to make this distinction, the cynic in me thinks). The concern is that it enters houses through their foundations where it accumulates indoors due to the lack of air movement. This is apparently quite an issue in basements particularly.

So, on the surface at least, for someone wanting to build an essentially underground house this seems quite a worry. But I like to be thorough, so I started thinking about what factors contribute to the information gleaned above, which seems to be widely accepted as fact (at least by organisations trying to sell solutions, and the US government agencies charged with addressing the problem).

Firstly, it is clear that Radon levels vary from place to place. Much of the initial information I came across was from the US, describing it as unusually high compared to global levels. ARPANSA conducted an Australia-wide survey in the 1990s which seems to indicated Australian levels (¬11 Bq/m^-3) are lower than elsewhere (¬40 Bq m^-3).

Very comforting.

However, upon closer inspection this refers to the indoor levels only. This is significant because there's a possibility (indeed probability) that the variable causing the difference between areas relates to the type of house rather than any inherent difference in the Earth's crust. In truth, I would assume a bit of both. The plot thickens.

One can assume, for instance, that part of the issue in the US with basements is because they aren't as well ventilated as above-grade spaces, leading to an accumulation of Radon as it off-gasses through the foundation. One might also assume that in deep winter or the extremes of summer people actively seek to limit ventillation in their houses to keep air temperatures consistent and not waste all that energy-hungry air conditioning. It's unclear, though, how much this plays a part in geographical differences regarding Radon accumulation.

I could hypothesise based upon the above map (for example, I notice that the area of high concentration on the NSW/VIC border is an area in which it is both very hot in summer an very cold in winter, perhaps leading to accumulation due to lack of ventilation year round), however I have no way of finding out if this is in fact that case. It also just so happens that that very area of higher concentration is close to where we intend to build, so figuring out if it is an inherent difference in the earth's crust or some function of prevailing building and climate control techniques seems rather important.

As I have no way of knowing this (despite several hours of energetic googling on the subject) I turn instead to methods of limiting Radon accumulation as it seems like perhaps we should consider doing that anyway. Pleasantly, after a bit of searching, I found that the most effective methods are based around aspects of construction we will need to do anyway when building with earthbags. Problem solved!

Firstly [A] a permeable space below the floor (eg. gravel, which we have to do anyway for drainage). Secondly [B] a non-permeable layer above A but below the floor (eg. plastic, which is easy to add in during construction). Thirdly [C] sealing all openings in the floor (eg. around pipes, which one would want to do anyway). Next [D] a pipe from below the foundation to above the roof to allow the gas to disperse into the atmosphere rather than indoors (pretty easy to include during construction), and [E] a roughed in electrical box to put a fan in later (seems a little pointless, but I totally get that if you're going to do a thing do it properly).

There don't appear to be any regulations around controlling Radon levels indoors (although I may not be looking for the right thing there). So, given that the risk of Radon accumulation is essentially completely unknown (fancy government survey's not withstanding), but addressing the possible risk is pretty easy if done during construction and almost impossible if attempted later, I figure we might as well add in the pipe.

Compost water heating

I've seen a few compost water heaters now, on my search for hot water systems. I was far from convinced that they were for us, however. Most seemed either a lot of work to maintain, or don't last very long. The geek in me still likes the idea, though - somehow it seems a little like hacking nature.

So I started thinking - maybe a compost heap water heater won't work for us for the main house. But before the house is up we'll be on site for a period of a month or two at least, essentially camping. Whilst Kyle and I are no strangers to camping, we're not against doing so with some added comforts. It also occurs to us that we'll be more able to conscript convince our friends and relatives to help if we have ammenities available.

To that end, I quite like the Compost Wheelie Bin Hot Water System (there are any number of other sites showing a similar design - I couldn't quite be bothered to track down who did it first, I just gave up once I'd found a site that quoted measurements).

It works pretty much like the name suggests - you stick green stuff in a wheelie bin, with a water coil down the centre. Several sites I found suggested it would last comfortably for about 4 weeks, though they also said it takes about a week to peak and suggested starting another one two weeks in to tag team them. Two of these, swapped in and out, could do quite comfortably during the build for our little house, and let me have my experiment.

For a more long-term solution I quite like the Pain Mound, and this is where I could see compost-powered water heating working for Kyle and I.

I first found this one through an instructable, and later tracked down the original book on the matter (long out of print but available as pdf). The bits that really caught my attention were that Pain's goal wasn't just convenient cheap energy, but fire risk reduction in the forests near his farm (an ever-present risk in rural Australia). A bit more hunting around and I found someone else had taken on the water heater idea and very recently produced another book on the matter, which I'm about to order a copy of.

It might take me a bit of work to convince Kyle (or even just myself) that compost-powered hot water is a good move though. The particular lifestyle we're looking for does not involve isolating ourselves from the world entirely and digging in off-grid. We'll still have our day jobs, we just aim to be less dependent upon them. Whilst education is a fairly safe industry to work in most of the time, in that the job itself isn't going anywhere, the idea of being able to retire at 35 if the work dries up (or if the mood takes us) is an attractive one. Not that we'd have to, we just could if we wanted to - the idea is to have choices, open up options, rather than lock ourselves into the traditional game of life.