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felsmand

Double storey extension costs

Darren Felsman
6 years ago

Hi, Sorry if this has been covered. I am demolishing the rear section of my home and replacing with a double storey extension. Am wondering how to come up with a ball park estimate calculation.

- Ground level is 80 sqm and upper is 80sqm so 160sqm in total.
- Example square metre rate used is $2200 .

Is the calculation just double the square metre rate for 1 storey or do you apply 50% to the upper level?

For example

A) 80sqm + 80sqm = 160sqm x $2200 = $352000 OR

B) 80sqm x $2200 + 80sqm x $1100 = $264000

I realise there's many other variables but am curious about which approach is more widely used.

Thanks

D.

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