Depends on budget. Many dwellings (probably majority actually) don't setdown the floor structure to end up with a flat floor throughout. It costs extra money to achieve for something that is to most people un-noticable. High quality dwellings do this all the time however. If you're going to that level of detail you should also look at setting down the floor edge where the sliding/stacking/bifold doors are (if you have them) so that the door sill is flush. This something you'll see continuously more often than the bathroom/ens floors. It was mentioned on 'The Block' recently and I've now had numerous clients asking about it and/or presuming that this how all floors are done.

having the space in the roof is one thing, but a whole other exercise converting ceiling structure into floor structure and getting the structure down to the ground, supported etc...even more complex on smaller jobs, not to mention finding space for stairs which typically involves collateral knock-on effect to lower level layout.......best you arrange a consultation/visit from an architect to discuss the practicalities a realities of costs involved........these things are usually possible, but ultimately dictated by costs......... In regards to the process, as architects we begin with several design stages (& if required Planning/DA) and then eventually move into working drawings once a design has been finalised and refined. There is a bit of a process involved and typically fees/costs will be ballpark anywhere from 5-15% of the construction cost of the project, depending upon the scale and complexity. On smaller jobs like this the % fee will be at the higher end of the scale and if it's too small often an hourly rate or fixed/packaged fee basis is the only way to render services Hope this gives you a bit of an idea, but best to do some homework and speak directly to a few local design professionals/architects to get some idea of what their process and fee structures are, because ultimately everyone operates and services projects differently... Good luck Cheers PD :)

HI again! I've spent the past few days visiting far flung industrial estates to look at where the CarbonLite product is manufactured and my friend's double/triple glazing factory. (I, too, am more comfortable with the panelised wall/floor/roof systems than modular, after visiting the Modscape factory...which was very impressive but ...not for me). On my travels I was a bit disappointed to find that the CarbonLite walls in the factory, ready to go out for construction, were not made with the 'recycled PET bottle' insulative layer but with glass wool batts. Also, some of my queries couldn't be addressed due to a lack of technical knowledge on behalf of the person I made a time to speak to at the factory. The fellow I spoke to the day before, who has a potentially rival business, was extremely knowledgeable and I'm hoping to work with him towards costing our house, which is still in the design phase. Our site has excellent views to the south east which is what got me thinking about triple glazed windows and now I have fallen down this rabbit hole of new ways of thinking... Nevertheless, I have become much more interested in the Passive House concept and intend exploring further to see if 1. we will be able to afford it 2. if we can find a skilled, Passive House certified builder for South Gippsland and, 3. if we can work out whether it is just a bit of a fad that may be overkill in Australia! Do you think Passive House is here to stay? I'm trying to reconcile the passive solar/passive house principles- I've been so bound to the idea of thermal mass it's a hard one to let go of! However, i do prefer not to live on a concrete floor! Having just read 'dreamer's' link I think I may have been bedazzled by the triple glazing fairy dust rather than our reality of not being millionaires! Habitech looks interesting but I think it comes with the external cladding and i don't love the versions I've seen so far... I am completely in agreement with you regarding designing a house with the space you need rather than building some voluminous thing with space to burn, just for the sake of it! Ridiculous and irresponsible on a planet that is already using up far more resources than is sustainable over the not-much-longer term.

It would be such a shame to rip up your beautiful floors, to try and do polished concrete now would be such a hard and costly job, along with the mess and the uncertainty of getting a good job that you may not like on completion as suggested, why not embrace your floors, decorate with the industrial look that you love , maybe a brick or concrete look wall could look really stylish and cost a lot less in $’s and stress