PPOR - Prefab Concrete Panels

[danwatto]

Hi All,

My wife and I are looking to buy our PPOR and we've found a house that "ticks all the boxes" in a suburb with good transport, and is GREAT value for money.

However it is made of prefab concrete. The agent said they can erect the structure in a day or two that way, and it limits the construction time but other than that there aren't any major disadvantages.

We found:
On the inside it looks great
On the outside, some walls are a bit plain, but we can change that.
A very fine crack! Near the top of the outside wall. It is double story and a huge panel has been used on one side from ground to roof.

Has anyone had any experience buying houses made like this? Anyone heard of any drawbacks? or advantages?

Does it mean the house is worth less than a brick one?

We want to buy the house, but we aren't familiar with this building method...

Needless to say, our offer WILL be subject to satisfactory building inspection even though it has a warranty.

Any advice would be appreciated.

Many Thanks

Daniel

 

[Rolf Latham]

Hiya

Tilt Slab pre fab concrete is very common in commercial style propertiesand they seem to survive allright.

As to the perception..........

ta
rolf

 

[kph]

Is the inside lined? with drywall or gyprock?
Just curious if there is any insulation between the inside skin of the concrete panel and the inside wall, or if the panel is the only wall.

Reason being that a solid concrete panel is a great 'heat sink' or heat soak and make a good thermal bridge from the outside to the interior therefore these structures can reflect the outside temperature more readily which is not always a good thing.
This can be overcome with good design using solar design principles.

If you were proposing to build on a vacant block and were asking if this was a good method to use then I would say no, but seeing as it is already build, then as long as it performs thermally ( maintains confortable inside temerature and environment ) then there is no reason not to buy it just because its a tilt up concrete construction.

Its more expensive to use this type of construction for resi compared to brick veneer or double brick, but works well for a tight site where you don't have good access, and it should go up quicker.

Its easy to change the outside appearance if you are not happy with it by texture coating or rendering or even cladding.

kp

 

[danwatto]

The inside of the external walls is painted without gyprock.
The internal walls between the rooms are gyprock, which allows running wires etc.

We viewed on a 36degree day and it wasn't overly hot inside without the air con. However it might take a few days before concrete builds up heat in summer? The previous day was cooler.

I think if it does get hot, there is ducted air conditioning throughout which I love to have

Yes we were thinking of using some textured paint. We've got the better homes and gardens home design program, so we'll have to program in the plans and try out some ideas.

It's interesting to read though that some people actually prefer a cement render to brick, for example this article thinks bricks are ugly!
http://www.homedesigndirectory.com.au/articles/FeaturedProducts/CementRender.shtml

I never thought that, but it gives us a nice new perspective.

 

[kph]

Yeh would personally agree with those sentiments.
Bricks were introduced to Britain by the Romans and we do not seem to have progressed much since then!!

If you viewed on a 36 degree day and it didn't seem hot then maybe the design has taken into account orientation and shading to minimise the summer sun's impact.

Proper solar design however would remove the need to have any air conditioning, but not always easy to achieve due to the size and orientation of urban blocks.

 

[Ausprop]

Yeh would personally agree with those sentiments.
Bricks were introduced to Britain by the Romans and we do not seem to have progressed much since then!!

it was interesting walking around ancient Rome looking at the brickwork. Looked like something that could have been buitl in 60's suburbia Oz. Amazing to think we are still building the same (on the whole anyway).

 

[RumpledElf]

I want a castle out of that concrete prefab stuff as an office when we're rich and infamous.

Actually I just want a castle.

Drove past some more houses today with turrets on. Lovely big grand old things with a sort of keep on, there's quite a few near where I live. Not a castle, but good enough.

Can you make turrets out of prefab concrete or do I have to go back to the drawing board?

 

[kph]

Nah no need to go back to the drawing board.
Its all been reinvented.
You can have ANY shape you want, turrets included.
And its made of cement or concrete coated EPS ( expanded polystyrene)
The EPS is shaped first then spray coated with the cement finish.

 

[RumpledElf]

<mr burns>
excellent
</mr burns>

Doesn't that concrete prefab stuff that's reinforced with polystyrene better thermal properties than just plain concrete blocks? I vaguely recall that stuff is one of the better construction materials for keeping houses cool. Plain cement on the other hand, yes, its got terrific thermal mass, and once its heated up it takes ages to cool off, but that's no different to a solid brick or stone house.

There's some very cool and very underused alternative building materials out there.

 

[kph]

Yep.
The use of this product is common in Europe and the US but has not caught on here yet.
Usually know as SIP construction as the panel is a Structural Insulated Panel.
Excellent thermal qualities and works as well in hot climates as well as cold.

Effectively becomes a BIG esky once built.
If Eskimos have figured out how to live in Igloos' then no reason why Aussies can't live in Eskys' !!

 

[danwatto]

Thanks guys.

The agent did say it has good insulation, but I don't believe everything I hear first time. The building inspector will tell me more on this.

That stuff looks similar.

I might have to add some turrets soon!

By the way, does anyone know a good Sydney solicitor? We've had our offer accepted


Cheers

 

[Belu]

kph - cost vs traditional brick?

 

[kph]

The million dollar question...what does it cost compared to ....brick

Short answer is that standard brick construction is cheaper ( maybe cheapest hence why it is so popular)

Longer answer is that there are a number of 'costs' to be considered.
First cost is the cost to manufacture the building materials used ( energy required to make bricks, cement etc)
Second cost is the cost of the building ( the one everyone focuses on)
The third cost is the ongoing cost to keep the house cool/warm ( energy required to maintain a comfortable temperature)

If you look at the total cost, then it makes sense to use materials that are as thermally and energy efficient as possible.
This will become more obvious as energy costs rise in the near future.

 

[danwatto]

Yeah he did say that it does cost more, it's just quicker to erect and the whole house can be done in a month.

I think most people not being used to it are unsure about buying one of these, but I'm very happy for the difference in sale price compared to similar brick homes, it's allowed me to be able to afford to actually buy the perfect floorplan that I always wanted.

Some of the lower price is on account of a busy road behind the house, but with the bedrooms at the front and the living area at the side I can't see it affecting the price that much (It's $250,000 cheaper than a similar brick one down the road). The road is set higher than the house and I didn't find the noise to be very loud. The back fence is a piece of crap though.

Anyone know what the best fencing is to block car noise? Next-door has a concrete fence.
The side fences are colourbond but for the back I'm not sure what to replace it with. I'm thinking colourbond being steel may even make the noise worse as it won't absorb it well?

Are there any specialist fencing products for noise absorbtion?

Cheers

 

[alpina]

love seeing houses being built from contemporary materials.
i think prefab concrete panels are great although they do require a lot of thought regarding insulation and placement of plumbing and electrical points.
i think if i was to build a house, i would use this material.
cheers

 

[danwatto]

love seeing houses being built from contemporary materials.
i think prefab concrete panels are great although they do require a lot of thought regarding insulation and placement of plumbing and electrical points.
i think if i was to build a house, i would use this material.
cheers

Yes they need the internal walls as gyprock to run cables and points etc. Also a section of the external walls has some gyprock but you can't tell.

The issue with building is the expense of having a crane onsite and sourcing the material. However this is offset by the fact that your house will be complete in 1 week rather than 6 months so you save on holding costs a little.

In our case, the guy who built did 2 houses next to each other, so he was able to use the crane and material and got some economies of scale savings.

Insulation is not a problem, this place is like a fortress. We also have a busy road near the yard and inside we hear nothing unless the back sliding door is open.

 

[alpina]

so, how much more expensive is prefab over brick, when one takes into account saved labour vs crane cost vs manufacture costs vs cost of rendering brickwork etc? 10% more expensive or more? just looking for a ballpark

cheers

 

[danwatto]

I'm not sure actually, we bought the house already built.