Month: January 2010
Water is too cheap
Our last quarterly water bill was $248. This is too cheap. With water rates at this level, there is simply no way of economically justifying any of our water efficiency measures.
We’re not very efficient users of water yet. Having moved into a 100-year-old house, there’s plenty of progressive improvements to be made:
- installation of low-flow shower head (done)
- fixing dripping taps (done)
- water efficient washing machine (done)
- use of tank water for toilets (1/2 done)
- installation of dual-flush toilets (when we renovate the bathroom)
- installation of low-flow taps (now or as part of kitchen and bathroom renovation?)
- water efficient dishwasher (when kitchen is renovated)
At present, our water usage is 494L/day,which is the same as the target rate for a 4-person household. It should be down at about 300L/day. So plenty of water savings to be made!
But let’s look at the economics of this:
If we got our water down to 300L/day, that would be a saving of 70kL per year. At a rate of $1.87 per kL, that would be the princely sum of $132.
That’s right. If we drop our water usage by 40% (!), we could save $132 per year.
On that basis, the water tank would take 50+ years to be paid back. Even a low-flow shower head ($80) would take several years to recoup the cost.
We’ll make the changes because we care about the environment, and it also makes us feel good. But spending thousands to save at hundreds doesn’t make a lot of sense in dollar terms.
Our comfortable middle-class life allows us to spend money on these things, but if money was tight, this wouldn’t even get on the list. If we’re going to get serious about water efficiency, the laughably cheap rate of water needs to be increased, and dramatically so.
I recognise that thisn’t an easy change, and that measures would need to be put in place to ensure that the poorer segment of society aren’t hit hard. But surely we can’t keep going on like this?
Understanding the house
While endeavouring to improve the sustainability of our house, it’s proven useful to build an understanding of every aspect of how the house is put together.
As we’ve had things fixed by our do-all tradesman Wilhelm, I’ve been working alongside him. Now I need to highlight that I have absolutely no handyman skills at all, and have struggled to hammer in a nail in the past. Nonetheless, I’ve been able to provide a second pair (of unskilled) hands, helping to speed up jobs, reduce the cost, as well as allowing me to see what’s done.
This has meant working under the floor to remove old building rubble (to remove hiding places for rodents, etc). It’s meant helping to nail insulation up in the roof.
This has led to a number of observations:
- It’s very cool under the floor. When we extend the house, can we put in place a wine cellar or “root cellar”? Can we make use of the cool air to ventilate our pantry, or maybe even the whole house?
- It’s very hot up in the roof. We’re putting in place reflective foil to reduce the amount of heat getting into the roof space, but once it’s in there it’s trapped. Can we do something to get the heat out?
Too often, houses can be a mystery, with hidden corners and spaces. Before making any major changes, it’s worthwhile exploring these spaces to understand how the house ticks.
Insulating the roof
One of the obvious ways of improving the energy efficiency of a house is to improve the insulation. In our case, there were tatters of 40-year-old insulation left in the rooft, but they weren’t going to do much for us.
We were lucky to get in quickly enough to receive the $1600 grant from the Australian Government for insulation. This applied even though we had some (useless) insulation in place:
The program targets homes that are currently uninsulated, or have very little ceiling insulation and were built before the mandatory thermal performance requirements under the Building Code of Australia were introduced commencing in 2003.
For us, the required insulation cost $1650, leaving us only $50 out of pocket. The standard insulation used by our chosen insulation installer was also excellent: Autex GreenStuf. It is:
- made of recycled plastic
- fire resistant
- free of any loose particles
- unappetising for bugs or rodents
It will basically last forever, and is even made in New Zealand, much closer than the European products on offer.
(The Government program has now dropped to $1200, but that should still be enough to do a moderate-sized terrace.)
That was just the beginning of the process. Doing some research, the insulation provides useful “bulk insulation”, slowing down the transfer of heat across the ceiling. But the roof space still gets extremely hot, as the corrugated iron roof heats up, and then re-radiates the heat into the house. After a while, this heat works its way down through the insulation, and into the living area.
The solution (or at least part of one) is to install reflective foil, also called sarking. We are using Aircell Retroshield, which is like giant bubblewrap covered in reflective foil on both sides. The shiny surface reflects the heat, and the air bubbles provide additional insulation (upwards of R3.2 in summer, R1.5 in winter).
For a new house, this is simply laid down at the same time the roof is put on. It’s a much slower job retrofitting it.
Thankfully I’ve got Wilhelm, our handy fix-everything-guy, to help me. So we’ve spent a number of afternoons up in the roof, nailing up the foil to the underside of the joists.
I think all of this is making a difference. Even with the back of the house completely uninsulated (old extension; flat roof), the house stays upwards of 10 degrees cooler than outside. Which is a good thing with the 35+ degree weather we’ve been having recently!
Becoming a sustainable water ambassador
When we put in our water tank early last year, we received a rebate from Marrickville Council, which was much appreciated. This also started a dialogue with the water folks at the Council.
As a result of this, I agreed to become a “Sustainable Water Ambassador”, and the details on this have just gone live.
There are details on the overall programme, as well as the poster (PDF) showcasing what we’ve done.
So far this hasn’t involved doing much, although we were one of the stops on a local tour of water sustainable houses. I’ve also been invited to be a member of a Council working party on sustainability, which should be interesting.
Three little pumpkins in a row
Now that the holiday season has passed, it’s probably time I got back into the blogging. Let’s kick things off with our first three pumpkins out of the garden.
Our small variety have gone great, with three more pumpkins on the way. Our large pumpkin plants seem more intent on taking over the world than producing edible bounty.
Following instructions I read somewhere, I’m drying out the pumpkins for a week, and then putting them under the house where it’s cool and dry. Apparently leaving on some of the stalk improves their shelf life.
(And yes, the third pumpkin is tiny. For some reason it decided to stop growing at that point, and waste-not-want-not…)
Lewisham House and Farm 