can put in skylight if you need more light ? more lights ? or build your fake wall a bit in and only high enough to hide the windows but not all the way up to the ceiling so you let in light from your 3 windows?

If the front of the house is west facing in Queensland and you have glass on that side of the house, in summer in the afternoon the sun beats down on this side for hours, heating up the whole house. There is some speculation on double glazing as some think that they do heat up, better than nothing. Once the sun hits the wall you are lost. These image are for north this is worst for west. A more passive means of cooling the house is to install tall enough thick leaves to the base trees on the western side so that they shade that elevation. Problem with that is that in winter, that sun would be nice. So you need trees that drop their leaves early winter and have them back on say September when the sun starts to heat up. Some trees hold onto their leaves till a few weeks before spring, so make sure you do your research and think root barrier up front to protect your footings. Photo below horizontal external shade screens, Another method is to shade the house with screens, i said house not windows. With western sun, it is low when it starts to clear the roof overhangs, so no amount of horizontal shade devices will make any real difference. The screens for western sun in Queensland must be of a vertical nature. So screens that hang OUTSIDE the house to around say 900 mm off the ground would be fantastic. Since the sun travels around the west from more south west in peak summer to west in winter, vertical blades tend to be ideal solution and should pivot, to deal with this moving sun. In the past, Queenslanders used to have these vertical screens on castors and they moved them around to suit the conditions, for some reason we did not learn from the past. This house the screens are not shading the walls at the bottom so they would still heat up. From the plans i see you are building in brick, so western sun and bricks in summer make an ideal oven. Takes bricks 12 hours to cool down depending on the colour. All material heats up in the sun, but bricks take longer to cool, light weight material which is properly insulated is a better choice and against popular opinion, glass is also a good choice, all better if vertically screened. Double brick tends to keep a house cooler and you might as well use the double brick for structure instead of the decorative nature of cavity brick house, but after a while that heats up and takes forever to cool. Studs hold up the roof, not the face bricks. Ever wonder why the house stands up during construction with stud wall and roof? Photo is vertical blades which pivot. A good landscape architect would be worth a look and they will know how to blend your style of house with the garden. North windows in Queensland even with no overhangs, (which is stupid in Queensland) do not get sun into the rooms, but in winter it might crawl in say 2 M which is nice. What are you doing with the roof and concrete tiles heat up nicely and the darker you make them the hotter they get, Colorbond is a good choice with all the hail we tend to get, or keep a stockpile of tiles for when they break. Colour also makes a difference to heat. Make sure you vent the roof space, whirly birds, and vented eaves or gable ends, make sure you fully insulate the roof and also ceiling, and choose a light colour. choose a style of external screens or trees to fit the house. See if that makes a difference to the report which is there to make your life better and we are talking the cost of air con for the life of the house, the reports are there to help save you money, maybe a bit more up front but worth it in the long running cost of a house. Ros

do you mean internal sliders or hinged doors? what would be the purpose of the wide opening? where will the doors stand when open? do the open doors interfere with movement around both the bedroom and the room from which you enter the bedroom? will the wide opening reduce available space for furniture placement on either side?? only consider a bigger than normal (820mm wide) opening if it improves the space and doesn't compromise movement or furniture for both rooms

Oklouise and Sirius, thanks for the ideas. Actually the first one could work us very well, removing part of the wall and having a partition instead of a door. A lot more work but we are pretty handy. Regarding the barn door, most of the people I talked to agreed it might date quickly, unless I use a different mechanism than the ubiquitous black one you see everywhere,maybe.