Running cladding in opposite directions gives a contemporary look. Many examples I've seen seem to vary the profile width each. ie. narrow verticals juxtaposed with broader horizontals. You could clad base in a recycled plastic timber-look product or composite timber cladding. (Colour stable and no maintenance). Stone could look fab too. Painting it the Farrier would definitely be simplest. You could do a contrast with the verandah floor and its edge.

I love our glass splash back. We choose an electric blue as the rest of our kitchen has a lot of timber, white and windows. Easy to keep clean, withstands the heat of the stove and you can choose any colour you like. you can even match it with an existing wall colour if you wanted to. The aluminium one sounds good, but I think that in our climate with salty air and a lot of moisture it would show corrosion spots very quickly. macymacmaples, I agree that there are a lot of choices for tile, but the 'easy to replace' comment doesn't really make sense to me. Then again, I have no idea how easy it would be to replace our splash back, which is wedged between the overhead cupboards and the benchtop - I still love it though, even after 10 years!!!

Wall-mounted AC units have a directional outlet on them, so you'll be able to set it to push air across the room. 7.5 metres is a long way for it to travel though, probably won't go that far. The fans are not that powerful. As for the output size, the rule of thumb for these things is 100W per square metre, so 5kW is about right. With 7kW you should be okay. However your desk is right by a north-facing window so that's where the sun will come in and cook you, unless there's some shading. The suggestion for a fan is a valid one, and will probably make a big difference. I'm not sure is position 2 would really be a lot better since it's directed at the stair void anyway. Thermal comfort is always a tricky one since it's very subjective. Ultimately you'll just have to try it and see whether you feel too hot or cold. But overall I think it won't make too much difference which of the two locations the AC unit is in.

There are other things to consider than just cost. There may be council height restrictions, setback requirements from boundaries, and limitations on windows overlooking the neighbours. Large two metre wide cantilevered overhangs are structurally difficult and expensive to build. Don't forget the aesthetics - nobody wants to live in an ugly, out of proportioned house. Don't measure the value of a house by the size, number of square metres and number of living rooms, as there is much more to a well designed home, such as light, flow, functionality, how it performs in winter and summer, and how it fits into the neighbourhood. Best of luck with your research, Dr Retro of Dr Retro House Calls/Dr Retro Virtual Visits