Trying to be a bit green

At this point we'll take a bit of a "time-out", leap sideways and have a look at some sustainable-type things we're trying out at eightmangana that we couldn't/didn't do at the last build.  Before you think we're entirely altruistic and honourable in our intentions, a lot of the following make sense to us because they're going to save some money in the long run - which is a good thing.  They also happen to be 'green' principles - and pretty logical really.

Principle #1 - Orientation:  Found in any and every sustainable house design book, website, blog and pamphlet but rarely seen in real life bricks-and-mortar - not sure why, because it's simple and makes sense.  Face your main windows and living area north (don't care where the street is - doesn't matter...) and make those windows big.  Put as minimal an amount of glass to the south as you can (and make those rooms less-used ones).  Avoid western-facing windows as they'll catch late afternoon sun that you can't block out = uncomfortably warm.  Do what you like on the east - it's where the sun comes up in the morning...  All this was in our minds as we looked for a block to build on - in our case the view and the sun are in the same direction, which makes things a lot easier.  Of course, we'll insulate to billy-oh as well to make sure the heat that gets in stays in.

Principle #2 - Eaves/Shading:  They don't have to be the industry standard and better if they're not.  Idea is that eaves make shade.  The amount of shade depends on how wide the eaves are, how far above the windows they are, and where the sun is.  Our eaves annoy our builder and will annoy the roofers because they're all different, but they'll let winter sun into our main windows (=warmth... beautiful, not-possible-to-manufacture, sunshine-type warmth) but block out the summer sun from those big north-facing windows (because summer sun rides much higher in the sky than winter sun).  I used a highly technical piece of software called Publisher to check angles, heights, eave widths, etc and see if they worked:

 

Principle #3 - Thermal Mass:  It's great having a builder and builder's dad who are brickies, because we have 3 walls inside the house that are going to be solid block filled with concrete.  Why?  A substance like concrete absorbs heat from its surroundings, so when the house is warm these walls warm up - and most importantly, hold the warmth.  Then, as the house cools down later in the day the concrete releases that warmth back into the room.  Works in both cold and hot climates.  Free sunshine, collected in a giant wall-sized heat-bank, free warmth even after the sun goes down - perfect!



What you might call a "slim-line wall-mounted panel heater" - or just a big grey concrete wall...

 Principle #4 - Sunshine is free:  Hence the big windows and also our foray into solar energy at the more technological high-end.  Eightmangana is going to have both solar power (back-to-the-grid) and also solar hot water.  It remains to be seen how cost-effective both these are but we've found some good deals and think they'll be worth the investment this time - shouldn't take too many power and hot water bills to see how good a decision it is.  The hot water is a continuous gas-boosted system - gas supplements if the sun don't shine, but only as the water is used (hence the 'continuous') and only to the temperature needed.  Well-insulated, on-ground tank keeps water hotter for longer and doesn't need reinforced roof trusses.

Principle #5 - Rain is free too:  At least for now, until someone finds a way to meter and charge for it.  But we plan to put in a tank or two to catch some of this resource before it runs off the roof, through the pipes, into the gully and away to the sea.  Beats buying water from the council...  Plus it tastes great!

So there you go.  Our little bit for the planet and hopefully the hip-pocket as well.  Easiest time to do these kinds of things is when you're building