
We are planning to build some rooms (bedroom, second bathroom) under our 1970s small hardiplank home. It's on a flat block and has a concrete slab under. The posts are steel apart from 3 brick stumps at the front.
The height under the house from concrete to bottom of the supporting beams is only 137cm, so would be less than this when finished, just a bit short of legal height (bummer!) .
So my questions are, firstly, is there any way to get around the legal ceiling height issue other than raising the house? I don't know exactly what I'm asking here, lol. I think I had visioned some vague notion of a waffle type ceiling... which would probably look gross even if possible?
Also, does it really matter (eg. to home buyers, resale value) if the rooms aren't legal height, assuming that we will be wanting to sell in about 5 years time? I know that's probably a dumb unanswerable question, but we're just after some different opinions and new points of view that perhaps we haven't thought of. pros and cons

Would it cost less to raise the house because it's on a flat block? Would anyone know an approximate cost given that the block is flat, there is already a slab and only raising by perhaps about 10cm (and does cost increase with height raised?)?
Sorry so many questions, thanks in advance!
