I mentioned it in an earlier post:

viewtopic.php?p=184452#p184452

In the end we decided that mass walls were not required and that the slab was adequate.

We had it modelled with AccuRate and it didn't seem to make a difference to performance (if you can trust the operator and software).

It wasn't required either according to the glazing mass ratios quoted in Paolino and Baverstock's manual.

http://forums.envirotalk.com.au/Thermal ... t8093.html

Information given to was that Formatech cost about $160/m2. for a 150mm wall.

Building in brick veneer is definitely cheaper than double brick - except in Perth! However, this is only one perspective to look at it from ie construction cost. As people have stated earlier, having thermal mass on the outside of the building doesn't contribute to energy efficiency - it's when the thermal mass is on the inside that it does. Having said that, when another member stated that the best performer was double brick, that wasn't necessarily correct either. In a study done comparing different wall constructions in different climate zones (download the Green Book http://jameshardie.com.au/designtools) Reverse brick veneer outperformed other wall construction methods - including double brick. In fact, double brick performed relatively poorly against for example lightweight cladding on the outside, insulation and then gyprock in many climate zones and in most orientations.

The best place for thermal mass is inside, and frequently in the floor WHEN THE BUILDING IS WELL ORIENTED. When it's not, the thermal mass is actually a hindrance. On the same site you can watch a video with Steve King, an academic at the Built Environment department at UNSW talk about role of thermal mass...

A bit JH product bias but not a bad summary about how to design and build an energy efficient house.

Yes for thermal mass inside the home
and on the south side cool and north side warm
...dream is to have fish tanks (glass and concrete)
as room dividers and screen walls etc

Nathan
you seem pretty fired up on ICFs, why don't you do double brick and insulate the cavity (ie qasi reverse ICF). Or put hebel panels on the inside, insulate in the middle (bulk and reflective) then brick or sheet of whatever you like on the outside. You will then have a good effect feel / touch on the inside and awesome insulation and thermal mass.

perhaps i just dont like green bricks and ham! i am pretty keen for a new form of construction; as mentioned i believe that double brick and brick veneer just dont cut it here in Australia; its time for change and new methods must be looked at to insulate better.

ive seen 3x houses now with concrete forms; and i am convinced.. the advantages outweigh the cost.

Go for it! Then tell us cost / comfort / good / bad - we will learn from your experience. You could be the ICF pioneer. . . There is a book I saw in melbourne the other which is all about ICFs (a US book) it is in McGills in Elizabeth street (but you probably have it...)

lol not much of a pioneer, there are a few on here that have built with it. the houses ive seen people i have spoken too lala.. my own experience with climate and house construction is all relevant. i have plans currently in the design/draw stage so ive still got quite alot of research to do!

Hi,

I have been building with Zego ICF.

Initially, I also had the same problem of finding builders and tradies that were comfortable with using ICF. But after a bit of research I managed to find a builder that only builds with Zego exclusively. And he obviously has a whole group of tradies that he uses. So problem solved.

Some points to note with ICF:
- Yes it is more expensive. But looking back, I would not build with any other method. I was looking at building from standard brick veneer, double brick, and even concrete tilt slab!
- You really need to get double glazing to get the full benefits of ICF
- You have to factor in the cost of a full house render

I’m happy to discuss anything else you need to know.

Cheers,

R.

did you get other quotes from eco-block or thermacell? are you building 2x storey or 1? exterior and interior walls? more info etc..

-Nathan

Hi Nathan,

I am building a 2 storey with a garage sub floor (basement). Only external walls are ICF, with the exception of the home theatre, primarily due to sound proofing reasons.

I did get quotes from Thermacell and in terms of cost there wasn’t much difference. I would guess that it would also a similar cost for eco-block as well?

But the reason why I went with Zego:
- Their block heights are 300mm, and as most standard sizes are in divisible of 300mm I figured it would be easier to work with and eventually save me some $$$ in avoiding non-standard sizes.
- I attended the Zego training workshop and found it very informative and felt that there was enough support available, especially for the owner builder.
- I quite liked their wall brace system as it eliminated the need for scaffolding or having to manually make up the wall braces from wood. Saves time and money as far as I’m concerned.
- Zego also has the Fire Form, which I ended up using for retaining walls. Unlike regular Zego blocks, this creates a solid concrete wall and you can vary the thickness of the concrete core by changing the size of the connecting clips that you use.
- Zego also has a cladding system, which I also used for a parapet to hide the roof line.
- But I think most importantly, I was able to find a Zego builder who I was comfortable to work with. He builds exclusively with only Zego, has built heaps of Zego houses and has a whole team of tradies and sub-contractors who are not afraid of ICF and don’t charge you an arm and a leg for it!

If you require any more info, check out my blog (can be accessed via my profile).

Cheers,

R.

Hows this for a ressurrection...!! i thought it better to revive this thread with the mountain of info already in it, than to start a new one.

so we are currently in fairly early stages of planning and i have been looking quite seriously into using Zego for construction. Now i know its not the "perfect" system, but i think its a damn sight better than BV.. especially building in the Blue Mtns...

so im pretty set on wanting to go Zego for exterior walls (and some interior like the rumpus room and the HTR), but is it worth doing all the interior rooms in Zego also, or would a timber frame suffice?

does the cost of having Zego for interior walls, out-weigh the benefits? What are the benefits of having them as interior walls compared to timber? would love to hear any stories from those that have built using zego in any combination..

Sorry for the long post..


Cheers
Dan

I have built a house using ICF thermacell.

Looked at the others but thought this was better.

Also found a draft person who was brilliant.

But the bigger question would I build again with ICF?

Hmm not sure.

Certainly would never do brick double or single.

I would not do ICF for internal walls you want thermal mass, inside.

I did timber frames fill with concrete blocks.

Good Luck

Pulpo

I might as well chime in as well…
I built with Zego and have absolutely no regrets.

I’ve got Zego external walls and retaining walls. All walls in basement are Zego (load bearing) and home theatre is Zego (sound proofing).
All other walls are standard timber frames.

As for whether it will be worthwhile for all internal walls to be Zego, I would say no… mainly due to costs. This is especially the case if you are planning on a two storey house, as you will need beams to support the weight of the walls above.

Take a look at my blog: www.rlay1.blogspot.com

Cheers,

R.

I'd considered ICF for quite a long time for my house, but given how sensitive my location is to wall thickness, I've instead gone for lightweight timber framing with Kingspan insulated wall panels. It is probably the second most expensive option (forewent the steel framing) but the poor solar access means I wanted to maximise insulation and minimise thermal mass, while keeping my walls as thin as possible.

It took me about 18 months to reach this decision.

I have poured a concrete slab with an electric heating cable to make the living area comfortable in winter.

Depending on the location however, I would probably use rammed earth construction in rural areas, ICF in suburban, and lightweight construction with insulated panels in inner urban areas.