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Is Insulation a legal requirement in WA?
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TOPIC: Is Insulation a legal requirement in WA?

Re: Is Insulation a legal requirement in WA? 3 years, 7 months ago #200

Yes climate zone 5 no insulation to external walls provided that there is:
-there is sufficient shading on the external walls of all storeys and
-adequate energy efficient glazing is installed for all storeys
-floor of lower storey containing habitable rooms is concrete slab on ground and the internal walls of the lower storey are masonry.


However I do find that last part amusing, as you could build the house open-plan without any internal walls to habitable rooms and it would therefore comply, and build in the walls with any building materials later!
(bathrooms and laundry, and pantry/store and other non-habitable rooms can have walls of any material anyway as non-habitable rooms are exempt from energy efficienty requirements)

Climate zone 4 also allows no insulation or shading to external walls if: (option b)
-there is adequate energy efficient glazing, but there is a higher penalty for the calculation than in climate zone 5.

The glazing one is sometimes tricky though, because depending on other factors, sometimes you need smaller windows to comply which doesnt make sense as youd want to let more sun inside during winter. It can take a lot of fiddling with the window sizes and glazing in order to make it comply, but with patience it can usually be done. Then what you build your windows with later doesnt really matter. Technically, you dont need to submit building plans to change your windows after the house is built, so why does it matter if you dont put the same windows there in the first place, that were used to make the glazing calculator comply. The whole window compliance thing is a bit of a joke I reckon!
Often the deemed to satisfy report plus the glazing calculator is required to comply, if the softwar star rating doesn't comply. The glazing calculator is available from the abcb website so your designer should be able to do the calcs on the design for you to ensure that its right, during the design stage.
Last Edit: 3 years, 7 months ago by sharon.ponsford.

Re: Is Insulation a legal requirement in WA? 2 years, 7 months ago #242

  • aaron.t
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This whole issue is a non-issue - the UWA Kalgorlie trials of rammed earth versus insulated rammed earth showed no real difference between the two.

Re: Is Insulation a legal requirement in WA? 2 years, 7 months ago #243

It's certainly an issue for some climate zones until the building codes (National Construction Code) are changed.

Until that happens the councils must assess building license applications based on the NCC. (formerly the BCA) unless the building codes have a mid-year update, which doesnt happen its always May 1st. But who knows something as major as this evidence may require a mid-year update.

But that's great news they've proven it at Kalgoorlie! Yay! for rammed earth!

It certainly shows this whole energy efficiency conspiracy against rammed earth construction is nothing more than a scam by those who write the building codes as I"ve always suspected.

Thanks for letting us know! (Yay!!) Happy dance!!
Last Edit: 2 years, 7 months ago by sharon.ponsford.

Re: Is Insulation a legal requirement in WA? 2 years, 7 months ago #244

aaron.t wrote:
This whole issue is a non-issue - the UWA Kalgorlie trials of rammed earth versus insulated rammed earth showed no real difference between the two.


Insulation with RE walls is a MASSIVE issue in WA, especially if you are climate zone 4 or 5.
It can add significant cost, or push an owner builder's RE project just a step too far into the "overly complex" and force them to reconsider RE, either due to complexity in build or most likely due to complexity/compromise in getting their design to "6 stars" stupid fng NatHERs. A real pity.

The UWA research is showing that heat loss due to other mechanisms far out weigh the advantage the insulation gives. Lets hope they can convince NCC to stop forcing insulated RE to get a build permit.
Thermal bridges MUST be considered. Currently, NatHERs simulations do not fully consider thermal bridging.

The heat losses into the footings, slab and/or top cement bond beam (via thermal bridging) far exceed any gain insulated panels make. One paper I read thermally modelled losses due to thermal bridging and indicated losses greater than an entire wall of single glaze windows!

Don't get me wrong, insulated RE (I-RE) can make a huge difference but only if careful consideration in the design of thermal bridges is also given to insulated panels.

SIREWALL made thermal bridge reduction their mission and have succeeded in building I-RE in environments from Alaska (with permafrost and -20*C) to Arizona.
You should see their construction detail (esp around windows) incorporating insulated panels into a RE wall whilst ensuring minimal thermal bridges. Very complex construction detail! A lot of effort!

If you can spare a moment, please read the EXCELLENT paper "Rammed Earth Thermodynamics" 2015 Krayenhoff.

There is an interesting free article "A high-performance Rammed Earth wall system for Cold Climates", google should provide. In particular note the "continuous line of insulation" and "thermally broken bond beam".

The very good book 2012 "Modern Earth Buildings" has a good section just on thermal bridging and should be available if you go to your local library and request it. I've been AMAZED at the WA library system and what it can get. They do a great job.

NatHERS models convective heat flow fantastically (brick home heated+cooled via air con). NatHERS does not model radiant heat flow as well (high thermal mass home). A RE house is currently disadvantaged when getting it through energy assessment.
Last Edit: 2 years, 7 months ago by william.turner.

Re: Is Insulation a legal requirement in WA? 2 years, 6 months ago #248

  • aaron.t
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I should add that the poor performance of the insulated rammed earth was probably due to poor construction details allowing thermal bridging - well constructed insulated rammed earth (e.g. Canada's SIREWALL) works.
Last Edit: 2 years, 6 months ago by aaron.t.

Re: Is Insulation a legal requirement in WA? 2 years ago #249

Finally got hackers out of the site!

Yes that's correct.

Geraldton is climate zone 5, so no insulation required if slab on ground and masonry internal walls.

If you are not going to build all masonry internal walls, I would build one internal feature wall which should be enough to get it passed the energy efficient assessment.

I'd recommend an energy efficiency assessor who is experienced in making rammed earth pass.

There just shouldnt be so many work arounds required.
The two test houses in Kalgoorlie proved that insulation makes no difference in climate zone 4. Climate zone 5 would be the same as its milder than 4. Climate zone 4 has colder nights.
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