# Forum Home Renovation Sub Flooring  Lift or dig? building in under a QLDer

## IanWain

Hello, 
I have just purchased an old queenslander.  I want to add room to it an renovate while my current lease runs its course.  One major job i would like to do is to build in underneath. 
The property was restumped with concrete stumps recently.  
Under the house is dirt.  It runs on a slope from so the roof height is 1800mm going down to 1000mm as it goes up the slope.    
I have a number of questions... 
How far would i have to raise it to get it legal?   
Can i raise it and put some sort of extender on top of the stumps or do i have to replace the near new stumps it has? 
Can i dig down to make it legal height? 
Would i be able to raise it and put some sort of support beams in to reduce the amount of stumps under the house.  
or should i just level out a section, put some astroturf under there and use it to store my tools? 
Thanks for your knowledge and experience in advance. 
Ian

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## Oldsaltoz

Check with your local council as the rules change depending on post codes among other things. 
It should be possible to have a steel frame made up to stand on the existing stumps, or you can go for an all steel structure and place the posts in a manner that best suits the new layout. 
Would avoid digging down, apart from having to replace many of the existing supports you are inviting some serious drainage problems. 
Good luck.  :Smilie:

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## Bloss

:What he said:  best to raise and generally cheaper too (such as the example given for plumbing & drainage - easier to extend up than rip-out and replace). Not really a DIY job IMO and in Qld plenty of people who have done this for a living for a long time. Some of them would no doubt be happy to do just the lift and have you do the disconnect service prep work and the reconnect work (using your labour and any subbies needed - plumber, sparky etc). That can save you some money if you have the skills and the time.

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## Draffa

Sums I've done suggest it is cheaper to dig down that build up (if building new), but you're lifting, not building, so lifting is going to be cheaper than digging (depending on the slop of your block and driveway orientation you may end up doing both). 
2.7m clearance seem to be the generally considered height for a 'liveable' room.  If you're lifting there's no benefit to a lower height other than a slight saving in uprights costs.  I'm aiming for ~3000mm slab-to-floorboards as this will let me hang 'racks' from the beams for additional storage.  I've been quoted $35/foot for 75*75mm steel stumps, so the additional cost to go from 2700 to 3000 isn't that big of a deal in the scheme of things. 
If you raise, get an engineer to draw up a plan which eliminates as many stumps as possible, using steel beams to support across the gaps.  6m spans seem common (two-car garage).  You may be able to replace the old beams using Laminated beams and skip the steel, but I don't know about prices or difficulty.  The house I previously lived in was raised and had a single I-beam run down the middle, eliminating three concrete stumps and gaining us heaps of useable space

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## Pulse

For habitable rooms, 2400mm is the minimum floor to ceiling clearance in the BCA, but 2700mm is a bit more spacious. 2700mm lift gives room for the slab, ceiling battens etc. without encroaching on the 2400mm clearance.  2100mm is acceptable for kitchens, storerooms, laundries and the like. 
Cheers
Pulse

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## jago

I'm No expert and the consensus seems to be raise have a look at brissyboys go to whoa   http://www.renovateforum.com/f176/mo...-anyway-90246/  
he raised his...

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## Draffa

> For habitable rooms, 2400mm is the minimum floor to ceiling clearance in the BCA, but 2700mm is a bit more spacious.

  Yeah, 2400 is a bit tight these days, since people tend to be taller than they used to be.  Add in lights, fans, etc, and it's almost cramped.

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