After I had finished my Archi Masters I was working for an architecture firm who also did a small amount of work for a volume builder. They were actually a pretty good quality builder and at least got the orientation of their 'pre-designed' plans correct. We had the ability to make minor changes to every job and it pained me to see so many simple to implement passive options not being incorporated. Had most of their clients known that they would be saving MONEY over the longterm by making a few minor changes to suit their site, they all would have done it. The problem is unless someone can sell this idea to them as a financial/lifestyle choice, many just think it is about saving the world. It is a no-brainer if you have in interest in it, but for those who don't know, there is no-one there selling it to them, especially on the lower end of the market.

Thank you everyone for all your help and advice! Yes, we live in an inland part of Southern Australia that is very chilly in winter and exceedingly hot in summer. So efficiency is a very important part of our build. From the picture you added Louise, I think a "coffered" ceiling looks like what I would call an "up lift". I'm glad to have a second on that option ;) The picture looked good, and could defiantly be an option over the dining table I think. Thanks jbantick I looked up "scissor trusses" and they look like a great idea as well. I'm just not sure how they would run. From the entry across the dining area (N to S) or across the whole length of the 3 zones E to W ? The middle of the roof line (running E to W) doesn't run in the middle of the living zones (if that make sense) as it stretches across a hall way on the south side. If it ran this way would it look a bit off centre? How did you in vision it? Thanks for your thoughts guys.

As bigreader has suggested any soft furnishing you can add will all help to reduce noise. Not knowing what kid of treatment you offer I would try a small well fitted head set for your clients playing soft relaxing music.

This wasn't your question, but looking at a possible boxed out window in the open plan kitchen dining living it shows just how limited you space is. The following 3D overview shows a boxed out window seat. I have run the kitchen along the same wall as the new window, The Island is 2m x 900 with 1m between the wall base cabinets and the island and 1m between the Island and the wall where your plan shows cabinets. If you have/had cabinets along the other wall as shown on your floor plan they will be 600 deep this would make the island 1400 x 900 which is small. Has your kitchen been renovated and were you considering that, if not. Looking at the overall size of your open plan area I would be considering 1 or 2 large stacker doors to open up to the rear alfresco, that's what I would do but you need to choose what will work for you PS I think that the boxed out window at the front of the house is a lovely idea but possibly not right when it faces West.