Thread: Big storm and no power in SA

Originally Posted by donh54

Wouldn't it be smarter if they hadn't started building houses that require air conditioning to make them habitable?

Originally Posted by rovercare

Solar passive residences, vs cheap, mass produced housing, hahaha...

Originally Posted by rovercare

You can build a residence to house yourself in Sub tropical, temperament climate that will maintain a reasonable average of 18* indoor temperature....but most are not willing to spend the money,

Different parts of the country require different designs to be energy efficient and comfortable. The house we built in Yass was very comfortable, but would have been a nightmare in Darwin.

The issue in Yass, like Canberra, is the temperature variation; not so much from summer to winter, but from day to night. A 20 degree difference between day and night is not uncommon.

Consequently what is needed is a house that will provide some temperature stability. People often assume that insulation is the way to achieve that. However probably more important is thermal mass.

Our walls on a modest 3 bedroom house weighed 50 tonne and the slab about another 28 tonne. That provides a lot of thermal mass. As a result, when the temperature outside varied by about 20 degrees, the temperature inside the house varied by about 4 degrees.

Visitors on 30+ degree days assumed the house was air conditioned. The hottest the house ever got inside was after five or six consecutive days in the mid to high 30s with nights dropping to about 20. On the last day of that period, the temperature outside was 38 degrees and it reached 28 inside, but a couple of degrees of that was because we were cooking a roast Christmas dinner.

The external and internal walls were compressed earth blocks. NOt mud bricks!

That house looked quite conventional and cost about the same as using conventional materials. At that stage the cost of external walls was about 8% of the total cost of a house, so using a different material for the walls hardly affected the total cost one way or the other.


Other features that didn't cost anything were the orientation on our 52 acre block, the size and location of the windows and the size of the eaves and verandahs. It didn't even have double glazing. That costs more.


An energy efficient house doesn't need to cost the earth and doesn't need to look radical. The important thing though is that it isn't a one size fits all situation. Maybe that is a bit like energy systems. There is no single, simple answer that will work everywhere.

A corrugated iron house can be cool inside if it is well-designed with plenty of shade and airflow.

Originally Posted by DiscoMick

A corrugated iron house can be cool inside if it is well-designed with plenty of shade and airflow.

My understanding is that such a design could work well in Darwin. It wouldn't do for Yass though.

Nice house you have there VNX!!!

Our '46 bungalow has 2 foot sandstone walls and can survive 4-5 days over 40c without a temperature crisis inside - just ceiling fans used.
Any more than that and it's not nice, then a cool change takes 2-3 days to normalise the walls again.

We just need to fit the verandahs down each side now..

Much more efficient than any new houses around here...

Originally Posted by vnx205

Different parts of the country require different designs to be energy efficient and comfortable. The house we built in Yass was very comfortable, but would have been a nightmare in Darwin.

The issue in Yass, like Canberra, is the temperature variation; not so much from summer to winter, but from day to night. A 20 degree difference between day and night is not uncommon.

Consequently what is needed is a house that will provide some temperature stability. People often assume that insulation is the way to achieve that. However probably more important is thermal mass.

Our walls on a modest 3 bedroom house weighed 50 tonne and the slab about another 28 tonne. That provides a lot of thermal mass. As a result, when the temperature outside varied by about 20 degrees, the temperature inside the house varied by about 4 degrees.

Visitors on 30+ degree days assumed the house was air conditioned. The hottest the house ever got inside was after five or six consecutive days in the mid to high 30s with nights dropping to about 20. On the last day of that period, the temperature outside was 38 degrees and it reached 28 inside, but a couple of degrees of that was because we were cooking a roast Christmas dinner.

The external and internal walls were compressed earth blocks. NOt mud bricks!

That house looked quite conventional and cost about the same as using conventional materials. At that stage the cost of external walls was about 8% of the total cost of a house, so using a different material for the walls hardly affected the total cost one way or the other.


Other features that didn't cost anything were the orientation on our 52 acre block, the size and location of the windows and the size of the eaves and verandahs. It didn't even have double glazing. That costs more.


An energy efficient house doesn't need to cost the earth and doesn't need to look radical. The important thing though is that it isn't a one size fits all situation. Maybe that is a bit like energy systems. There is no single, simple answer that will work everywhere.

No argument here, well, in regards to differing things required, hence the reference, different in tropical or arctic climates, funnily enough

The only thing is you are incorrect, it does cost to do, look in any urban sprawl and pick the north facing blocks?....thats a quick elimination, and the costs for a "regular person" to build with a volume builder and there chosen spec home, vs alterations for any variance to suit solar passive add dramatically to the cost

Thermal mass, thermal bridging, solar gain, cross ventilation etc etc....all pretty simple stuff really, but rarely used, such a shame

Suburban blocks on which you can orient a house for maximum benefit can certainly be in short supply. About the time we were building in Yass, there was a report in the Canberra press that of about 100 new blocks that had been surveyed in Canberra only 20 were suitable for locating a house to get much benefit from passive solar heating.

You mention the cost of altering standard designs and I am sure you are right. However at the time we were doing the research before committing to building our house, I found an article which may have been published by the CSIRO (or maybe not. It was a long time ago).

A standard Jennings house had been very slightly modified and its energy consumption compared with the standard version. Apart from one modification that I will mention later, they were just no cost things like changing the size and location of some windows, changing the size of the eaves and locating the house facing the right way.

For a year, computers opened and closed doors and windows and turned lights on and off etc and the modified house used a significant amount less energy. I think it was about 25% less, but I remember it was quite a bit.

The other modification was a rock pile under the house. Warm air was blown over the rocks during the day and the heat in the rock pile was used to warm the air that was blown into the house at night. The rock pile was not used the first year, but was employed the second year. The conclusion was that although the rock pile improved the efficiency of the house, it wasn't worth the extra cost.

The conclusion of the article was that even a standard project home from one of the biggest builders of project homes could be made significantly more efficient at no cost. (If you could find a block of land that allowed you to orient the house correctly. Good luck with that. )

So even if it does cost to make a house more efficient, it really shouldn't.

I haven't read the full article yet, but I just found this, which may have some useful information about the sort of things we are discussing.
[ame]http://www.industry.gov.au/Energy/Energy-information/Documents/identifyingcostsavingsbuildingredesignachievingene rgyefficiencystandards.pdf[/ame]

Originally Posted by vnx205

Suburban blocks on which you can orient a house for maximum benefit can certainly be in short supply. About the time we were building in Yass, there was a report in the Canberra press that of about 100 new blocks that had been surveyed in Canberra only 20 were suitable for locating a house to get much benefit from passive solar heating.

You mention the cost of altering standard designs and I am sure you are right. However at the time we were doing the research before committing to building our house, I found an article which may have been published by the CSIRO (or maybe not. It was a long time ago).

A standard Jennings house had been very slightly modified and its energy consumption compared with the standard version. Apart from one modification that I will mention later, they were just no cost things like changing the size and location of some windows, changing the size of the eaves and locating the house facing the right way.

For a year, computers opened and closed doors and windows and turned lights on and off etc and the modified house used a significant amount less energy. I think it was about 25% less, but I remember it was quite a bit.

The other modification was a rock pile under the house. Warm air was blown over the rocks during the day and the heat in the rock pile was used to warm the air that was blown into the house at night. The rock pile was not used the first year, but was employed the second year. The conclusion was that although the rock pile improved the efficiency of the house, it wasn't worth the extra cost.

The conclusion of the article was that even a standard project home from one of the biggest builders of project homes could be made significantly more efficient at no cost. (If you could find a block of land that allowed you to orient the house correctly. Good luck with that. )

So even if it does cost to make a house more efficient, it really shouldn't.

I haven't read the full article yet, but I just found this, which may have some useful information about the sort of things we are discussing.
http://www.industry.gov.au/Energy/En...ystandards.pdf

I have the perfect block, Northern aspect, views of the entire valley, slightly down the hill to give protection from SW winds...but I like where I live, the location is great, this place will be for later in life, although my property up the bush with roof and shipping container would suffice!

There is things you can do even on a conventional home, I have no air con, just ceiling fans, single glaze on most of the house, poor shading, but I do have window shutters and with a bit of household management, you can keep a reasonable temperature, most of the year, the winter is made up for with a stupidly oversize wood fire, as it has no solar gain, the bare concrete slab and internal brick walls helps with thermal mass though

but instead we slap undersize solar HWS on that use more energy than they save to attain 6 star energy rating on poorly orientated and designed homes

Originally Posted by rovercare

... .... ...
Thermal mass, thermal bridging, solar gain, cross ventilation etc etc....all pretty simple stuff really, but rarely used, such a shame

Something even simpler and cheaper was employed by a friend of mine.

Knowing that air movement can give a misleading impression about the temperature, he installed thermometers inside and outside the house. A slight breeze outside can fool you into thinking it is cooler outside.

He opened and closed the doors and windows when the thermometers indicated that there would be a benefit in doing so. He found that gave much better results than just flinging the windows open or closing them when he thought it might be cooler or warmer outside.

He was surprised at how much better he was able to regulate the temperature inside the house when he had actual data about the difference between inside and outside temperatures. All it cost him was the price of two thermometers.