There is a comprehensive guide at the Bluescope website at http://www.steel.com.au/products/coated-steel/colorbond-steel/basix-and-bca-classification

Hi! I think your lighting choice should be influenced by what you see as the focal point of the space. If you have spectacular views out your windows, you may not want eye catching different sized pendant lighting fighting with the view. However, being west facing, you may have the top part of the window wall shaded with awnings or a verandah - therefore your lighting would not distract from the view. Maybe also think about what is going on below the lighting area: think about the overall style you are going for in the room: are the furnishings minimalistic so therefore could do with some eye catching lighting? or do you have spectacular artworks or an eyecatching coffee table? If so, dimmable, LED downlights could be the answer instead of feature lighting. Too many "wow" factors can confuse the eye and create a sense of unease. Hope that did not confuse you further!! Like the other people said, a photo of the existing space would help.Sounds like an amazing room. All the best with it! :)

@ minebathroom and @ Luke Buckle, our electrician has informed us that we don't have to put solar panels on our house roof if we don't want to for aesthetics or if for example the roof was old as you mentioned Luke. Panels can be placed on a shed or garage roof anywhere on your property if you are rural like us for example, as the power can be directed into the grid from anywhere the solar panels live and that doesn't have to be on the house roof. We would love to go solar but agree with all your other points @minebathroom, too expensive and expected lifespan and feed in tarrifs are very ordinary but then there's also the back up service too, will the company still be around in one year let alone 10 years. When our electrician got his solar, he got such a fantastic tarrif rate which was offered at the very start of the solar revolution, he was recieving a cheque or refund of something like $500 a quarter but the rates are so low now, there is certainly no chance of recouping some of the instalation costs, although I wouldn't be so fused about that if I thought I would get say 20+ years out of the system before it begun to possibly fail in some way. Things do have to get allot more reliable if nothing else!!

ddarroch Thanks for all the great suggestions. Pity indeed about the directions of the sun and view. Can't change the profile of the block only can try to work out the best based on what it is. Very valid points about the heating VS. clerestory windows. We are in the temperate climate region which keeping warm it’s an issue in winter. We have thought about to have low-e glass in the south facing side but looks like we probably need to have double glazing in places like the north facing clerestory windows like you suggest. No ideas how much more double glazing will cost but certainly we need to include a fair amount into our budget. Agree with having a door separating the living from the back of the house like you said. Much better for heating and sound insulation. Again thanks a lot.