A friend of mine installed prefab along her balcony but they ran the length of the house wall, so we're pretty much protected from weather. She had screens installed at either end. Where you see the BBQ and cabinets in your photo, she just had a free standing BBQ. Her cabinets even housed her washing machine, bar fridge and dish drawer. Looked fabulous in white with her timber floor.

I would paint all the brick everywhere warm white...satin for occasional cleaning. That done I think everything else will look OK because the colours are natural. New doorknobs are always good. You could if you wanted paint all the bench and cupboards white or rich cream as well....MUCH more spacious effect. there is a product you put on first and wait and paint...Hardware will knw...something like PSo

Your kitchen is a good size but not huge so I would go with gloss white to match in with your lovely fridge. All white appliances. Light coloured bench top in the grey range. Backsplash, I'd go to tile expo, choose something you love and add some colour behind the stove, the rest of the splashbacks behind the sink etc in white subway tiles. Dark floors as you have chosen, all the walls in the house Dulux Whisper White. This is a great colour to go with everything, i use it all the time in my designs.

Ok so after all the feedback I made some changes. After looking at it, I would like to make entry point from garage on the garage wall, so you still enter into pantry, but you dont have to walk through pantry to gain access to the house. I would also like to flip bathroom and bed 3 so bathroom is centred between rooms. Also not convinced I should have entry to lounge from kitchen, should I have kept it entering from the entry. My only issues now is, do you notice how the bathroom steps in? This is because the ensuite is a bit bigger. Will it look ok once built or do I take that 30cm from my ensuite/main room to level it up? If so do I take 15cm from ensuite and 15cm from main bedroom? Also I really wanted the compartment bathroom that oklouise suggested. But its not big enough. Any ideas? My current bathroom is 3100 x 2600.