Self-sustainable homes

[Slybacon]

solaronline.com.au

[alphaomega]

i live in what you could call a self sustainable home.. north facing, mudbrick, poured earth floor, straw batt ceiling insulation, solar power, fire/solar heated hot water.. also 14 acres of paddock, bush, veggie/herb/ornamental gardens. we used some recycled timbers also no paint/chemicals..

 

forgot to mention, we also have a composting toilet, reed bed grey water treatment system, chooks, two sheep and a donkey.

[synchromesh]

Pictures, or none of it exists...

Nice link, Sly. Thanks.

[alphaomega]

Pictures, or none of it exists...

 

http://yfrog.com/5313112010jx

[synchromesh]

Beautiful, man. Thanks!

[alphaomega]

Beautiful, man. Thanks!

 

no probs mate. just PM me if u ever want any info/advice on anything.

[synchromesh]

Will do! Thanks, man.

[synchromesh]

What does it cost to build your own house?

[random]

Thats a good link thanks for sharing.

Wish I could afford it LOL I guess i'll just have to stick to my plan of buying a block out bush somewhere and putting a caravan on it!!

[WoodDragon]

Good link, Syncro - I read that a few years back and thought "too true". It's the reason I've yet to build on my land - I need to 'grow up' first and find a job that can keep up with the ridiculously inflating costs of building.

The other wake-up call that many would-be tree-changers need is to understand exactly how difficult it can be to maintain a rural property. An acreage has to be fenced (and re-fenced over time), and maintained to minimise or eradicate fire hazard and weeds, as well as being tilled, mulched, vegetated, watered and otherwise cared for in order to grow crops and habitat. These things take much more time and many more resources than most people give credit for - it's not a matter of a few hard weekends' work and she'll be right...

There's insurance, and off-grid service substitution (many folk from the city cannot adapt to things such as bucket-dunnies and solar showers...), and the transport cost of living remotely.

And then there's the small(!) matter of actually understanding what the land 'wants', and what it needs... Some folk are innately attuned to their land, and others learn to be so, and a very small third category blindly but fortuitously manage to do things right even if they don't realise that they've done so by sheer dumb luck. However, many are completely clueless even after living on their land for years, and all they end up doing is to help to drive it ever further away from a sustainable and ecologically-servicable state.

Many city folk would benefit fromspending a few months house-sitting in the country, or wwoofing, before buying a random block and expecting manna to fall from heaven. Some knowledge can only be gained by experience, although there are also many good references. I've owned rural land for years, and gardened and worked professionally in biology/ecology for decades, and I'm still learning both from experience and by reading. I won't recommend a swag of texts myself, partly because I believe that the very process of searching for information can be enlightening in itself, but I will mention two that I have currently dug out and have next to my bed - "Water For Every Farm Using the Keyline Plan" by P Yeomans, and "The Earth Manual - How To Work On Wild Land Without Taming It" by Malcolm Margolin. At their hearts both are fairly simple books, but nevertheless they contain a wealth of info. Margolin's is a US-focussed book, but this doesn't detract from many of the underlying principles, and he does a good job of making ecology accessible to the lay person. Neither is a complete manual, nor are they necessarily the best guides for particular circumstances, but for me they've both been money well-spent even though I knew much of the stuff beforehand.

Living in the country can be wonderful beyond words, but doing so comes at a financial, an emotional, a physical and an intellectual cost. Of course, for the right sort of person the last three (and even all of them) might not be "costs", but there is certainly a requirement for some energy to be invested in each category!

It's important though that a neophyte tree-changer doesn't start the dream with so many stars in their eyes that they can't see what they're doing.

[ThunderIdeal]

i recommended yeomans earlier in this thread. according to the little dream world in my head, it's the tall rural cousin of permaculture. permaculture came second and is foremost in my mind, but some of yeomans ideas should not be ignored yet the permaculture literature LITERALLY gives them no more than a few vague sentences. it's also handy to have the dual perspective, from memory yeomans order of priority began with things like fences and roads and of course dams rather than soil. i don't think either line of thought is more right than the other, it does depend on the land, climate, and what is intended for the land.

[WoodDragon]

Meeka.

Nothing wrong with that idea! Especially if the local council doesn't grow stroppy about it!

I have two caravans, and more and more I'm starting to wonder if I really need the house that I spent thousands of hours (literally) designing. If push comes to shove I could live in the vans, and concrete the floor of my 6x7 m shed and line it,and I should be good for years.

For me Stage 1 is an open-plan studio/workshop which will serve as a 'cottage', and even that's a 5-year plan. If I can never afford more than that then I would still be content, as I have the most important things already...

I should add to my previous post by saying that good shelter can be built much more cheaply than the budget detailed in Syncro's link, but such buildings might not comply with local building regulations. For some, this might not be a hassle; for others it can be. And usually the difference involves one or more of hard physical work, trade experience, years of hoarding materials, years of building, and simplicity of design/construction. If these aren't in easy supply, then the cost starts to climb...

[ThunderIdeal]

i said exactly the same things earlier in the thread and have probably made that exact post once every couple of years since i came here

[WoodDragon]

ThunderIdeal.

It's amazing, isn't it, that Holmgren and Mollison didn't employ keyline more in their work? Maybe there was an issue of 'intellectual property', although even the precepts of 'permaculture' came before them - Josef "Sepp" Holzer was on it a decade before Holmgren and Mollison.

Which reminds me - has anyone ever seen "The Agricultural Rebel"?

[Edit: Thunder, I missed your earlier post somehow, and only got on to this page when I clicked the 'recent posts' button.

It's a message that can't be too often repeated though - the field of scotch thistles down the road from me, where previously there had been a top-notch grazing paddock, reminds me that the message takes a long time to sink in for some!]

Edited December 14, 2010 by WoodDragon

[synchromesh]

Thats a good link thanks for sharing.

Wish I could afford it LOL I guess i'll just have to stick to my plan of buying a block out bush somewhere and putting a caravan on it!!

 

Caravans are usually pretty expensive aren't they? Wouldn't you rather live in a nice cabin instead?

If push comes to shove I could live in the vans, and concrete the floor of my 6x7 m shed and line it,and I should be good for years.

 

That size would be perfect for me. Thanks for all of the input man.

[ThunderIdeal]

i just find it queer that i always make those exact comments when keyline comes up.

i acknowledge that permaculture is a collection of older techniques, but as a bundled collection, along with an ideology, it is only as old as the word itself. i suspect it's because of the ideology that keyline is ignored? permaculture is supposed to be low input high output, keyline is all just a little bit too full-on and conflicting to really fit in there. i also wonder if yeoman had access to a similar understanding of soils wae have nowadays, leading to his low regard for soil improvement. not to mention agricultural soils weren't half destroyed back then like they are now. i don't have such a lofty knowledge as you must, but i've deemed it true that improved soil texture, soil life and organic additions (better soil) constitutes the most important factor in growing healthy, resilient plants if it's to be done without chemicals. would you agree?

Edited December 14, 2010 by ThunderIdeal

[synchromesh]

Mud walls give poor insulation: CSIRO

Now I don't know what to think.

[WoodDragon]

... but i've deemed it true that improved soil texture, soil life and organic additions (better soil) constitutes the most important factor in growing healthy, resilient plants if it's to be done without chemicals. would you agree?

Absolutely! I am an ardent adherent of the maxim that good gardeners don't grow plants, they grow soil. Get the soil right, and most plants will power along without too much further help.

Industrial fertilisation is a way of pumping crops without taking the time and exertion required to nurture a healthy soil ecology. It's hell on the structure and the biotic/abiotic composition of soil though...

[WoodDragon]

Mud walls give poor insulation: CSIRO

Now I don't know what to think.

This is not news - alternative builders have known this for decades!

The thing about mudbricks is that they have huge thermal mass, which helps to buffer extreme changes of temperature over short to medium periods of time. This makes mudbrick/rammed earth/cob great for areas that experience rapid changes of temperature, such as the hot day/cold night cycle in desert areas. They work fairly well for areas that don't have extended cold winters, but for places like Tassie they can be expensive to heat in winter once the retained summer heat is lost after autumn. In summers here they're great - αΩ's house is always pleasant even on the hottest days here.

In cooler climates high thermal mass walls still work well when they're used on the side of the house that receives the mid-day sun - north in the southern hemisphere, and south in the northern hemisphere.

For other sides there are alternatives that are just as envionmentally friendly. When I build my studio I will have mudbricks on the northern side, and either straw-clay or lime-hemp on the other sides. These materials combine some of the 'masonry' mass with huge amounts of integrated insulation, and the result is a much more insulative wall that still has some thermal mass. Sawdust can replace straw or hemp, and some people have used recycled paper, vermiculite, or perlite. There are a number of books that describe these techniques - I'll find titles and links for the ones I have if you can't chase them up.

And there's always strawbale building. These walls are hugely insulative, and with the benefit of a bit of thermal mass embodied in the render.

But the claims that mudbrick walls are bad simply because they are not very insulative is simplistic. In the right environment, used in the right way, they can remove almost all requirement for heating/cooling. The mudbrick community has been trying to educate bureaucracy about their naïve dismissal of mudbricks for years, but non-simplistic approaches are more than building regulators seem to be able to handle...

It's a matter of horses for courses.

[Slybacon]

How do Mudbrick homes fair against sustained rain and the ensuing mould and fungus?

[synchromesh]

Pretty good I would think. I mean, The Great Wall of China still seems to be doing fairly well...

WoodDragon - That study has its flaws anyway dude. Here, check this out:

http://www.buildingcommission.com.au/resources/documents/Mud_bricks_Fact_Sheet_12_July.pdf

[WoodDragon]

How do Mudbrick homes fair against sustained rain and the ensuing mould and fungus?

That's an interesting, and a two-part, question.

Unstabilised mudbricks (that is, no cement and sun-dried) can have good resistance against the physical force of sustained rain, but over time they will erode if exposed to direct rain. If they are rendered they may have quite good protection - lime-based renders can be quite resilient to rain. However, most unstabilised mudbricks are covered by an eve or by an awning that protects them from direct rain contact, and in this case they will last for centuries. Remember the old builders' adage...? Give a house a good hat (roofing) and boots (foundations/footings) and it'll stand for lifetimes.

The incorporation of rain protection is usually a standard design feature anyway, as there are other reasons to have eves/awnings. One alternative to putting a good hat onto the house is to stabilise the mud with cement during the mixing process. The resultant bricks usually have 5-10% cement, and are not much different to concrete blocks in terms of embodied energy/carbon, although they still retain the æsthetic of a traditional mudbrick. Stabilising also increases the cost, of course, and will incur the derision of the more purist of muddies, who generally believe that there are few reasons to stabilise! For example, if it turns out that the soil is too sandy for making a strong mudbrick, then usually a rammed-earth wall can be made instead (although these are sometimes stabilised too... )

Some people build with unstabilised mud, and render with a cement-based mix. This is a disaster waiting to happen, because clay/soil bricks have a different coefficient of expansion relative to the very rigid cement renders, and they also have a very different water absorption capacity. If a cement render is applied to a non-stabilised mubrick wall, sooner or later the render will detach from the wall and fall away. The bottom line is that unless there are pressing reasons to do so, cement should not be used in an earth-masonry wall; there are many more appropriate materials that can be used.

The other issue with cement is something to which I alluded in the last paragraph. Bricks, mortar, and render that are bound which portland cement are impermeable to water: that is, they will absorb little or no water from the atmosphere. An unstabilised mudbrick, whether it is non-rendered, or rendered with clay, cow dung, lime or other traditional material, will actively absorb moisture from the interior of a house at times of high humidity. Conversely, they release moisture when the air is very dry. This means that an earth-masonry construction that is rendered with a non-cement material, will almost completely eliminate mould/mildew from a home, and have a very stable and livable overall humidity level. I've heard many reports of people with mudbrick or strawbale or cob houses never having to worry about mould, when their neighbours are all growing black muck in their bathrooms and grey streaks on their windows.

This moisture-absorption capacity has one implication though - it is important to have a damp-proof barrier if there is a risk of a lot of surface water on the ground. If no DPB is incorporated into the bottom of the wall, the bricks can wick water up from the ground, and evaporate it to the atmosphere. Over time this process draws salt into the wall, which crystalises just below the surface of the bricks where the water evaporates. This causes the outermost layer to spall off, and over time the bricks will fall to pieces.

I'd better shut up, or I'll end up typing all evening!

Edited December 20, 2010 by WoodDragon

[random]

Posted 15 December 2010

meeka, on 13 December 2010 - 01:37 PM, said:

Thats a good link thanks for sharing.

Wish I could afford it LOL I guess i'll just have to stick to my plan of buying a block out bush somewhere and putting a caravan on it!!

syncromesh wrote:

Caravans are usually pretty expensive aren't they? Wouldn't you rather live in a nice cabin instead?

Not the type of caravan i'm thinking about... and what I'd like and what I can afford are two different things..

but its nice to dream and read threads about such.

[Slybacon]

That's an interesting, and a two-part, question.

I'd better shut up, or I'll end up typing all evening!

 

Thanks for that input. Certainly interesting to learn of moisture absorbency.

Another question to get your typing fingers ready....

How about salt water in coastal locations?

[WoodDragon]

Another interesting question indeed.

I've not encountered a great deal of material pertaining to salt spray and mud bricks, but I imagine that the impact is similar to what would happen if salt contacted a wall any other way.

Droplets of spray landing on a permeable earth wall would soak in to the surface, drawing salt in with them. At some point sooner or later, when humidity decreased, the water would evaporate from the surface, leading to the deposition of accumulated crystaline salt on the surface and just underneath. Given sufficient time these 'salt flowers' would break up the surface, which would crumble away and lead to the process repeating as long as salt continued to be present.

The best protection would be a barrier that prevents the salt from entering the bricks. As I have said before, a cement render is impermeable, but cement and earth are a marriage made in hell, and sooner or later they will divorce. (As an aside, many civil engineers are in love with cement render, and advocate its use on fired bricks. If there is any appreciable movement of moisture into the bricks from the ground or from the interior of the building, such a render will sooner or later detach from and/or cause damage to the fired bricks, just as it would to an earthen wall).

One way to protect an earth wall in such conditions might be to use a linseed sealant. Linseed is not quite as "plastic-wrappy" as a polymer sealant such as Bondcrete, so it looks far better, and it tends to cause less spalling, as can happen with Bondcrete which sometimes emulates a concrete render due to its complete impermeability.

Another way might be to use multiple limewash layerings. Limewash is traditionally used almost as a sacrificial surface (just as lime mortar is a 'sacrificial' mortar between bricks), and it requires regular re-application for at least the first years of a wall's life. The benefit though is that any limewash that erodes away is easily replaced, and over time a repeated limewashed wall developes more and more surface strength.

Having said all this, each circumstance has its own peculiar and perhaps unique parameters, and it is really an area where consultation with experienced people and with specialist literature is probably required.

One place to start is this book on G00glebooks. Read down to page 107 at least - there are some relevant comments in between.

I'll try to hunt down some more references if I am able.

Edited December 21, 2010 by WoodDragon