I'm hopeful that a pro will provide you with some great ideas. Yours looks like some of the "befores" that they do brilliant changes to on the TV reno shows. Most architects will come up with excellent solutions within the space if that's what's required, but nothing worthwhile is likely to be done cheaply though.

although it's a lot more work the new floor will look so much better if you remove the skirting boards and restore after the new floor is laid...done care fully you should be able to save (most of) the old boards and then supporting them at waist height (across the backs of a couple of chairs or a table covered with old sheets) you can sand and repaint them, (and maybe repaint walls) before you put the skirting boards back and then you will only need to fill nail holes and joins and touch up paint ...so much easier than doing it down on your knees.. despite all the extra work the result will ne well worth it and not especially difficult and you can Google video advice for techniques tools to use that will make the job so much easier...good luck

@ddarroch - you suggest rotating the home so it faces a compass point. Which compass point would you recommend? I'm leaning towards north facing but would appreciate your thoughts on this. Based on what I have read online, and the fact that we live north of Brisbane in a rural/residential area, I am trying to achieve a house orientation that excludes direct sunlight and minimises radiant heat at all times of the year and maximising access to cooling breezes. I'm just not sure how to achieve this on the block we are now building on as I keep getting conflicting feedback.

what is the hallway marked .59 and your plan shows bed 2 opening off the master bedroom...it would help to be able to see the whole house plans before attempting an extra bathroom