Minimum ceiling Height QLD

Hi All, recently found this forum and have been busily reading through all it has to offer! It's a fantastic resource full of good practical advice and am hoping to get some advice of my own...

We have bought a Queenslander style house (in Brisbane for our PPR) that was renovated around 10 years ago and was raised and built in under. The 2 bedrooms (and lounge area) downstairs have a current ceiling height right on 2.4m with a lino type flooring throughout.
We wanted to replace this and lay hard wood flooring but obviously this flooring would be higher than the lino (approx 30 mm thicker). If we did this would it make the space under legal height and therefor make it an 'uninhabital' space? is the 2.4 measured from the slab or finished floor? how strict is the 2.4 rule?

And the second part to this is that there is also a large 'storage room' off the garage under there that could be made into another bedroom and or study. No worries about ceiling height here as the slab here is approx 100mm lower- but they have used a much bulkier support beam through this part and it protrudes slightly lower than 2.1m. I know it's OK to have a beam as long as there is 80% (or something like that) of the ceiling above 2.4m but is there a minimum height the space under the bean has to be for the space to be classified 'Habital'?

Thanks in advance for any advice!

 

If the rooms built downstairs have already been approved and registered with council i would go ahead and add whatever flooring. If not then get that done first. I would also get the storage room approved first then worry about flooring. Pretty much what i'm saying is get it all Approved first then do the cosmetics after. It will be worth more to you in the end. Strict will all come down to the guy approving it on the day.

 

Refer to the BCA

 

Thanks Andrew and Scott. I'll look into the approvals and BCA

 

As the others have said above refer to the BCA which you can get free access to here online Home | Australian Building Codes Board this is the overarching document for building regs. That being said not sure that an existing building would be governed under new regs, I do know that if you alter certain other building elements by a certain percentage then they must meet current regs. Speak to local council planning department perhaps.