Help in calculating $$

I'm trying to cost a small extension to our house. I do remember that builders work on a $$ per square, but I can't remember.

The extension is simple, single brick, stud/plasterbrd interior. 2 storey, concrete slab, t/g chipboard upstairs.however the lower will be my new shed and I'll line etc myself. Tile roof, 3 windows up, 2 down, no plumbing.

Dimensions 3.5 metres x 5 metres.

Anyone give a rough cost? No time to do it myself and I can't lay bricks (in a straight line that is)

Maybe a Hebel block construct would be cheaper? Exterior will be rendered.

Its just for an addtional bedroom on top and new shed below. All suggestions gratefully accepted.

Try going here and downloading the cost guide:
http://www.archicentre.com.au/html/downloads.html

Archicentre is a good base - and your extension SOUNDS relevatively simple, but as I discovered, estimate with the Archicentre, then times that by 2!!!!! :rolleyes: . Builders seem to add a "Pain in the backside" fee for extensions!

If there are no real problems with "joining" the existing with the new, then go Best Case Scenario = $800/m2, Worst Case Scenario = $1800/m2.

Sorry, no help really!

My estimation technique is to work out how much you can afford and think it is worth, then multiply by 5. :D

Trav

Estimating would have to be one of the hardest tasks when building anything; just a couple of points, are you owner building? if so the trades will inevitably add more on for dealing with an OB.
I think $1500.00 a m2 is a reasonable estimate. The Hebel will be more expensive, however if you're putting a room on top of your shed, it may be advantageous to use that for the floor, because its a very good insulator.
just a thought.

Quote:

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Originally Posted by floydus

Estimating would have to be one of the hardest tasks when building anything; just a couple of points, are you owner building? if so the trades will inevitably add more on for dealing with an OB.
I think $1500.00 a m2 is a reasonable estimate. The Hebel will be more expensive, however if you're putting a room on top of your shed, it may be advantageous to use that for the floor, because its a very good insulator.
just a thought.

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Probably not owner building, unless I finally give the daily grind away
Would Hebel be more costly? I know brickkies hate laying it, but if you use the thick blocks, you only require a single wall. Good point on the insulation tho.

If I did owner build and used Hebel, I'd do the lot myself excepting the sparky. My BIL built a significant extension on his house as an OB, and whilst the Hebel looked pretty wonky bare, when rendered etc, it looked like a bought one.

Thanks all for help, $25 should cover it?